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@ -1,43 +0,0 @@
name: CI
on: [push, pull_request]
jobs:
run:
name: "Build using Racket '${{ matrix.racket-version }}' (${{ matrix.racket-variant }})"
runs-on: ubuntu-latest
strategy:
fail-fast: false
matrix:
racket-version: ["6.6", "6.7", "6.8", "6.9", "6.10.1", "6.11", "6.12", "7.0", "7.1", "7.2", "7.3", "7.4", "7.5", "7.6", "7.7", "7.8", "7.9", "current"]
racket-variant: ["BC", "CS"]
# CS builds are only provided for versions 7.4 and up so avoid
# running the job for prior versions.
exclude:
- {racket-version: "6.6", racket-variant: "CS"}
- {racket-version: "6.7", racket-variant: "CS"}
- {racket-version: "6.8", racket-variant: "CS"}
- {racket-version: "6.9", racket-variant: "CS"}
- {racket-version: "6.10.1", racket-variant: "CS"}
- {racket-version: "6.11", racket-variant: "CS"}
- {racket-version: "6.12", racket-variant: "CS"}
- {racket-version: "7.0", racket-variant: "CS"}
- {racket-version: "7.1", racket-variant: "CS"}
- {racket-version: "7.2", racket-variant: "CS"}
- {racket-version: "7.3", racket-variant: "CS"}
steps:
- name: Checkout
uses: actions/checkout@master
- uses: Bogdanp/setup-racket@v0.11
with:
distribution: 'full'
version: ${{ matrix.racket-version }}
variant: ${{ matrix.racket-variant }}
- name: Install Txexpr and its dependencies
run: raco pkg install --auto --batch
- name: Run the tests
run: xvfb-run raco test -j 4 -p txexpr

5
.gitignore vendored

@ -1,7 +1,5 @@
# for Racket # for Racket
compiled/ compiled/
doc/
*~
# for Mac OS X # for Mac OS X
.DS_Store .DS_Store
@ -17,7 +15,8 @@ Icon
.Trashes .Trashes
# generated documentation # generated documentation
doc/*
scribblings/*.js scribblings/*.js
scribblings/*.css scribblings/*.css
scribblings/*.html scribblings/*.html
scribblings/pollen/* scribblings/pollen/*

@ -0,0 +1,165 @@
GNU LESSER GENERAL PUBLIC LICENSE
Version 3, 29 June 2007
Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
This version of the GNU Lesser General Public License incorporates
the terms and conditions of version 3 of the GNU General Public
License, supplemented by the additional permissions listed below.
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As used herein, "this License" refers to version 3 of the GNU Lesser
General Public License, and the "GNU GPL" refers to version 3 of the GNU
General Public License.
"The Library" refers to a covered work governed by this License,
other than an Application or a Combined Work as defined below.
An "Application" is any work that makes use of an interface provided
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A "Combined Work" is a work produced by combining or linking an
Application with the Library. The particular version of the Library
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Version".
The "Minimal Corresponding Source" for a Combined Work means the
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The "Corresponding Application Code" for a Combined Work means the
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You may convey a covered work under sections 3 and 4 of this License
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If you modify a copy of the Library, and, in your modifications, a
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whatever part of its purpose remains meaningful, or
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3. Object Code Incorporating Material from Library Header Files.
The object code form of an Application may incorporate material from
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5. Combined Libraries.
You may place library facilities that are a work based on the
Library side by side in a single library together with other library
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License, and convey such a combined library under terms of your
choice, if you do both of the following:
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is a work based on the Library, and explaining where to find the
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6. Revised Versions of the GNU Lesser General Public License.
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Each version is given a distinguishing version number. If the
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Library.

@ -1,9 +0,0 @@
MIT License for txexpr
© 2014-2019 Matthew Butterick
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

@ -1,27 +1,14 @@
## txexpr ![Build Status](https://github.com/mbutterick/txexpr/workflows/CI/badge.svg) txexpr
---------------
Convenience functions for working with HTML-style tagged X-expressions in Racket
Convenience functions for working with HTML-style tagged X-expressions in Racket 6.0+.
Install from the command line like so: Install from the command line like so:
raco pkg install txexpr raco pkg install txexpr
Then require it in your Racket file, in standard mode: Then require it in your Racket file:
(require txexpr) (require txexpr)
In safe mode (with contracts):
(require (submod txexpr safe))
Full docs are installed with the package. You can also [read the docs here](http://pkg-build.racket-lang.org/doc/txexpr).
## License
MIT
## Project status
Complete. I will maintain the code but no major updates are planned. Certain aspects of the API and implementation could be better, because much of this code was originally written during a more naive era of personal Racketeering. Still, it gets the job done, and I personally lack enthusiasm for diving back in. Full docs are installed with the package.

@ -1,6 +1,4 @@
#lang info #lang info
(define version "0.2") (define collection "txexpr")
(define collection 'multi)
(define deps '("base" ["sugar" #:version "0.2"] "rackunit-lib")) (define scribblings '(("scribblings/txexpr.scrbl" ())))
(define update-implies '("sugar"))
(define build-deps '("scribble-lib" "racket-doc" "rackunit-doc"))

@ -0,0 +1,273 @@
#lang racket/base
(require (for-syntax racket/base))
(require racket/match xml racket/string)
(module+ safe (require racket/contract))
(define-syntax (define+provide+safe stx)
(syntax-case stx ()
[(_ (proc arg ... . rest-arg) contract body ...)
#'(define+provide+safe proc contract
(λ(arg ... . rest-arg) body ...))]
[(_ name contract body ...)
#'(begin
(define name body ...)
(provide name)
(module+ safe
(provide (contract-out [name contract]))))]))
(define+provide+safe (txexpr-tag? x)
(any/c . -> . boolean?)
(symbol? x))
(define+provide+safe (txexpr-attr? x)
(any/c . -> . boolean?)
(match x
[(list (? symbol?) (? string?)) #t]
[else #f]))
(define (validate-txexpr-attrs x #:context [txexpr-context #f])
; ((any/c) (#:context (or/c #f txexpr?)) . ->* . txexpr-attrs?)
(define (make-reason)
(if (not (list? x))
(format "because ~v is not a list" x)
(let ([bad-attrs (filter (λ(i) (not (txexpr-attr? i))) x)])
(format "because ~a ~a" (string-join (map (λ(ba) (format "~v" ba)) bad-attrs) " and ") (if (> (length bad-attrs) 1)
"are not valid attributes"
"is not in the form '(symbol \"string\")")))))
(match x
[(list (? txexpr-attr?) ...) x]
[else [else (error (string-append "validate-txexpr-attrs: "
(if txexpr-context (format "in ~v, " txexpr-context) "")
(format "~v is not a valid list of attributes ~a" x (make-reason))))]]))
(define+provide+safe (txexpr-attrs? x)
(any/c . -> . boolean?)
(with-handlers ([exn:fail? (λ(exn) #f)])
(and (validate-txexpr-attrs x) #t)))
(define+provide+safe (txexpr-elements? x)
(any/c . -> . boolean?)
(match x
[(list elem ...) (andmap txexpr-element? elem)]
[else #f]))
(define (validate-txexpr-element x #:context [txexpr-context #f])
; ((any/c) (#:context (or/c #f txexpr?)) . ->* . txexpr-element?)
(cond
[(or (string? x) (txexpr? x) (symbol? x)
(valid-char? x) (cdata? x)) x]
[else (error (string-append "validate-txexpr-element: "
(if txexpr-context (format "in ~v, " txexpr-context) "")
(format "~v is not a valid element (must be txexpr, string, symbol, XML char, or cdata)" x)))]))
(define+provide+safe (txexpr-element? x)
(any/c . -> . boolean?)
(with-handlers ([exn:fail? (λ(exn) #f)])
(and (validate-txexpr-element x) #t)))
;; is it a named x-expression?
;; todo: rewrite this recurively so errors can be pinpointed (for debugging)
(define+provide+safe (validate-txexpr x)
(any/c . -> . txexpr?)
(define (validate-txexpr-element-with-context e) (validate-txexpr-element e #:context x))
(define (validate-txexpr-attrs-with-context e) (validate-txexpr-attrs e #:context x))
(when (match x
[(list (? symbol?)) #t]
[(list (? symbol? name) (and attr-list (list (list k v ...) ...)) rest ...)
(and (validate-txexpr-attrs-with-context attr-list)
(andmap validate-txexpr-element-with-context rest))]
[(list (? symbol? name) rest ...)(andmap validate-txexpr-element-with-context rest)]
[else (error (format "validate-txexpr: ~v is not a list starting with a symbol" x))])
x))
(define+provide+safe (txexpr? x)
(any/c . -> . boolean?)
(with-handlers ([exn:fail? (λ(exn) #f)])
(and (validate-txexpr x) #t)))
(define+provide+safe (make-txexpr tag [attrs null] [elements null])
;; todo?: use xexpr/c provides a nicer error message
((symbol?) (txexpr-attrs? (listof txexpr-element?))
. ->* . txexpr?)
(filter (compose1 not null?) `(,tag ,attrs ,@elements)))
(define+provide+safe (txexpr->values x)
(txexpr? . -> . (values symbol? txexpr-attrs? (listof txexpr-element?)))
(match
; txexpr may or may not have attr
; if not, add null attr so that decomposition only handles one case
(match x
[(list _ (? txexpr-attrs?) _ ...) x]
[else `(,(car x) ,null ,@(cdr x))])
[(list tag attr content ...) (values tag attr content)]))
(define+provide+safe (txexpr->list x)
(txexpr? . -> . list?)
(define-values (tag attrs content) (txexpr->values x))
(list tag attrs content))
;; convenience functions to retrieve only one part of txexpr
(define+provide+safe (get-tag x)
(txexpr? . -> . txexpr-tag?)
(car x))
(define+provide+safe (get-attrs x)
(txexpr? . -> . txexpr-attrs?)
(define-values (tag attrs content) (txexpr->values x))
attrs)
(define+provide+safe (get-elements x)
(txexpr? . -> . (listof txexpr-element?))
(define-values (tag attrs elements) (txexpr->values x))
elements)
;; helpers. we are getting a string or symbol
(define+provide+safe (->txexpr-attr-key x)
(can-be-txexpr-attr-key? . -> . txexpr-attr-key?)
(if (string? x) (string->symbol x) x))
(define+provide+safe (->txexpr-attr-value x)
(can-be-txexpr-attr-value? . -> . txexpr-attr-value?)
(->string x))
(define+provide+safe (txexpr-attr-key? x)
(any/c . -> . boolean?)
(symbol? x))
(define+provide+safe (can-be-txexpr-attr-key? x)
(any/c . -> . boolean?)
(or (symbol? x) (string? x)))
(define+provide+safe (txexpr-attr-value? x)
(any/c . -> . boolean?)
(string? x))
(define+provide+safe (can-be-txexpr-attr-value? x)
(any/c . -> . boolean?)
(can-be-txexpr-attr-key? x))
(define (->string x)
(if (symbol? x) (symbol->string x) x))
(define+provide+safe (can-be-txexpr-attrs? x)
(any/c . -> . boolean?)
(ormap (λ(test) (test x)) (list txexpr-attr? txexpr-attrs? can-be-txexpr-attr-key? can-be-txexpr-attr-value?)))
(define (flatten orig-sexp)
(let loop ([sexp orig-sexp] [acc null])
(cond [(null? sexp) acc]
[(pair? sexp) (loop (car sexp) (loop (cdr sexp) acc))]
[else (cons sexp acc)])))
(define+provide+safe (attrs->hash . items)
(() #:rest (listof can-be-txexpr-attrs?) . ->* . hash?)
;; can be liberal with input because they're all just nested key/value pairs
;; but still need this function to make sure that 'foo and "foo" are treated as the same hash key
(define (make-key-value-list items)
(if (null? items)
null
(let ([key (->txexpr-attr-key (car items))]
[value (->txexpr-attr-value (cadr items))]
[rest (cddr items)])
(cons (cons key value) (make-key-value-list rest)))))
(make-immutable-hash (make-key-value-list (flatten items))))
(define+provide+safe (hash->attrs hash)
(hash? . -> . txexpr-attrs?)
(hash-map hash list))
(define+provide+safe (attrs-have-key? x key)
((or/c txexpr-attrs? txexpr?) can-be-txexpr-attr-key? . -> . boolean?)
(define attrs (if (txexpr-attrs? x) x (get-attrs x)))
(hash-has-key? (attrs->hash attrs) (->txexpr-attr-key key)))
(define+provide+safe (attr-set tx key value)
(txexpr? can-be-txexpr-attr-key? can-be-txexpr-attr-value? . -> . txexpr?)
(define new-attrs
(hash->attrs (hash-set (attrs->hash (get-attrs tx)) (->txexpr-attr-key key) (->txexpr-attr-value value))))
(make-txexpr (get-tag tx) new-attrs (get-elements tx)))
(define+provide+safe (attr-ref tx key)
(txexpr? can-be-txexpr-attr-key? . -> . txexpr-attr-value?)
(with-handlers ([exn:fail? (λ(e) (error (format "attr-ref: no value found for key ~v" key)))])
(hash-ref (attrs->hash (get-attrs tx)) key)))
;; convert list of alternating keys & values to attr
(define+provide+safe (merge-attrs . items)
(() #:rest (listof can-be-txexpr-attrs?) . ->* . txexpr-attrs?)
(define attrs-hash (apply attrs->hash items))
;; sort needed for predictable results for unit tests
(define sorted-hash-keys (sort (hash-keys attrs-hash) (λ(a b) (string<? (->string a) (->string b)))))
`(,@(map (λ(key) (list key (hash-ref attrs-hash key))) sorted-hash-keys)))
(define+provide+safe (remove-attrs x)
(txexpr? . -> . txexpr?)
(cond
[(txexpr? x) (let-values ([(tag attr elements) (txexpr->values x)])
(make-txexpr tag null (remove-attrs elements)))]
[(txexpr-elements? x) (map remove-attrs x)]
[else x]))
;; todo: exclude-proc will keep things out, but is there a way to keep things in?
(define+provide+safe (map-elements/exclude proc x exclude-test)
(procedure? txexpr? procedure? . -> . txexpr?)
(cond
[(txexpr? x)
(if (exclude-test x)
x
(let-values ([(tag attr elements) (txexpr->values x)])
(make-txexpr tag attr
(map (λ(x)(map-elements/exclude proc x exclude-test)) elements))))]
;; externally the function only accepts txexpr,
;; but internally we don't care
[else (proc x)]))
(define+provide+safe (map-elements proc x)
(procedure? txexpr? . -> . txexpr?)
(map-elements/exclude proc x (λ(x) #f)))
;; function to split tag out of txexpr
(define+provide+safe (splitf-txexpr tx proc)
(txexpr? procedure? . -> . (values txexpr? (listof txexpr-element?)))
(define matches null)
(define (do-extraction x)
(cond
[(proc x) (begin ; store matched item but return null value
(set! matches (cons x matches))
null)]
[(txexpr? x) (let-values([(tag attr body) (txexpr->values x)])
(make-txexpr tag attr (do-extraction body)))]
[(txexpr-elements? x) (filter (compose1 not null?) (map do-extraction x))]
[else x]))
(define tx-extracted (do-extraction tx)) ;; do this first to fill matches
(values tx-extracted (reverse matches)))
(define+provide+safe (txexpr->html x)
(txexpr? . -> . string?)
(define (->cdata x)
(if (cdata? x) x (cdata #f #f x)))
(xexpr->string (let loop ([x x])
(cond
[(txexpr? x) (if (member (get-tag x) '(script style))
(make-txexpr (get-tag x) (get-attrs x) (map ->cdata (get-elements x)))
(make-txexpr (get-tag x) (get-attrs x) (map loop (get-elements x))))]
[else x]))))

@ -0,0 +1,449 @@
#lang scribble/manual
@(require scribble/eval (for-label racket "../main.rkt" xml))
@(define my-eval (make-base-eval))
@(my-eval `(require txexpr xml))
@title{txexpr: Tagged X-expressions}
@author[(author+email "Matthew Butterick" "mb@mbtype.com")]
@defmodule[#:multi (txexpr (submod txexpr safe))]
A set of small but handy functions for improving the readability and reliability of programs that operate on tagged X-expressions (for short, @italic{txexpr}s).
@section{Installation}
At the command line:
@verbatim{raco pkg install txexpr}
After that, you can update the package from the command line:
@verbatim{raco pkg update txexpr}
@section{Importing the module}
The module operates in two modes: fast and safe. Fast mode is the default, which you get by importing the module in the usual way: @code{(require txexpr)}.
Safe mode enables the function contracts documented below. Use safe mode by importing the module as @code{(require (submod txexpr safe))}.
@section{Whats a txexpr?}
It's an X-expression with the following grammar:
@racketgrammar*[
#:literals (cons list symbol? string? xexpr?)
[txexpr (list tag (list attr ...) element ...)
(cons tag (list element ...))]
[tag symbol?]
[attr (list key value)]
[key symbol?]
[value string?]
[element xexpr?]
]
A txexpr is a list with a symbol in the first position — the @italic{tag} — followed by a series of @italic{elements}, which are other X-expressions. Optionally, a txexpr can have a list of @italic{attributes} in the second position.
@examples[#:eval my-eval
(txexpr? '(span "Brennan" "Dale"))
(txexpr? '(span "Brennan" (em "Richard") "Dale"))
(txexpr? '(span [[class "hidden"][id "names"]] "Brennan" "Dale"))
(txexpr? '(span lt gt amp))
(txexpr? '("We really" "should have" "a tag"))
(txexpr? '(span [[class not-quoted]] "Brennan"))
(txexpr? '(span [class "hidden"] "Brennan" "Dale"))
]
The last one is a common mistake. Because the keyvalue pair is not enclosed in a @racket[list], it's interpreted as a nested txexpr within the first txexpr, as you may not find out until you try to read its attributes:
@margin-note{There's no way of eliminating this ambiguity, short of always requiring an attribute list — empty if necessary — in your txexpr. See also @racket[xexpr-drop-empty-attributes].}
@examples[#:eval my-eval
(get-attrs '(span [class "hidden"] "Brennan" "Dale"))
(get-elements '(span [class "hidden"] "Brennan" "Dale"))
]
Tagged X-expressions are most commonly found in HTML & XML documents. Though the notation is different in Racket, the data structure is identical:
@examples[#:eval my-eval
(xexpr->string '(span [[id "names"]] "Brennan" (em "Richard") "Dale"))
(string->xexpr "<span id=\"names\">Brennan<em>Richard</em>Dale</span>")
]
After converting to and from HTML, we get back the original X-expression. Well, almost. The brackets turned into parentheses — no big deal, since they mean the same thing in Racket. Also, per its usual practice, @racket[string->xexpr] added an empty attribute list after @racket[em]. This is also benign.
@section{Why not just use @exec{match}, @exec{quasiquote}, and so on?}
If you prefer those, please do. But I've found two benefits to using module functions:
@bold{Readability.} In code that already has a lot of matching and quasiquoting going on, these functions make it easy to see where & how txexprs are being used.
@bold{Reliability.} Because txexprs come in two close but not quite equal forms, careful coders will always have to take both cases into account.
The programming is trivial, but the annoyance is real.
@section{Interface}
@deftogether[(
@defproc[
(txexpr?
[v any/c])
boolean?]
@defproc[
(txexpr-tag?
[v any/c])
boolean?]
@defproc[
(txexpr-attr?
[v any/c])
boolean?]
@defproc[
(txexpr-attr-key?
[v any/c])
boolean?]
@defproc[
(txexpr-attr-value?
[v any/c])
boolean?]
@defproc[
(txexpr-element?
[v any/c])
boolean?]
)]
Predicates for @racket[_txexpr]s that implement this grammar:
@racketgrammar*[
#:literals (cons list symbol? string? xexpr?)
[txexpr (list tag (list attr ...) element ...)
(cons tag (list element ...))]
[tag symbol?]
[attr (list key value)]
[key symbol?]
[value string?]
[element xexpr?]
]
@deftogether[(
@defproc[
(txexpr-attrs?
[v any/c])
boolean?]
@defproc[
(txexpr-elements?
[v any/c])
boolean?]
)]
Shorthand for @code{(listof txexpr-attr?)} and @code{(listof txexpr-element?)}.
@defproc[
(validate-txexpr
[possible-txexpr any/c])
txexpr?]
Like @racket[txexpr?], but raises a descriptive error if @racket[_possible-txexpr] is invalid, and otherwise returns @racket[_possible-txexpr] itself.
@examples[#:eval my-eval
(validate-txexpr 'root)
(validate-txexpr '(root))
(validate-txexpr '(root ((id "top")(class 42))))
(validate-txexpr '(root ((id "top")(class "42"))))
(validate-txexpr '(root ((id "top")(class "42")) ("hi")))
(validate-txexpr '(root ((id "top")(class "42")) "hi"))
]
@deftogether[(
@defproc[
(can-be-txexpr-attr-key?
[v any/c])
boolean?]
@defproc[
(can-be-txexpr-attr-value?
[v any/c])
boolean?]
)]
Predicates for input arguments that are trivially converted to an attribute @racket[_key] or @racket[_value]…
@deftogether[(
@defproc[
(->txexpr-attr-key
[v can-be-txexpr-attr-key?])
txexpr-attr-key?]
@defproc[
(->txexpr-attr-value
[v can-be-txexpr-attr-value?])
txexpr-attr-value?]
)]
 with these conversion functions.
@defproc[
(txexpr->values
[tx txexpr?])
(values txexpr-tag? txexpr-attrs? txexpr-elements?)]
Dissolves a @racket[_txexpr] into its components and returns all three.
@examples[#:eval my-eval
(txexpr->values '(div))
(txexpr->values '(div "Hello" (p "World")))
(txexpr->values '(div [[id "top"]] "Hello" (p "World")))
]
@defproc[
(txexpr->list
[tx txexpr?])
(list txexpr-tag?
txexpr-attrs?
txexpr-elements?)]
Like @racket[txexpr->values], but returns the three components in a list.
@examples[#:eval my-eval
(txexpr->list '(div))
(txexpr->list '(div "Hello" (p "World")))
(txexpr->list '(div [[id "top"]] "Hello" (p "World")))
]
@defproc[
(txexpr->html
[tx txexpr?])
string?]
Convert @racket[_tx] to an HTML string. Better than @racket[xexpr->string] because consistent with the HTML spec, it will not escape text that appears within @code{script} or @code{style} blocks.
@examples[#:eval my-eval
(define tx '(root (script "3 > 2") "Why is 3 > 2?"))
(xexpr->string tx)
(txexpr->html tx)
]
@deftogether[(
@defproc[
(get-tag
[tx txexpr?])
txexpr-tag?]
@defproc[
(get-attrs
[tx txexpr?])
txexpr-attr?]
@defproc[
(get-elements
[tx txexpr?])
(listof txexpr-element?)]
)]
Accessor functions for the individual pieces of a @racket[_txexpr].
@examples[#:eval my-eval
(get-tag '(div [[id "top"]] "Hello" (p "World")))
(get-attrs '(div [[id "top"]] "Hello" (p "World")))
(get-elements '(div [[id "top"]] "Hello" (p "World")))
]
@defproc[
(make-txexpr
[tag txexpr-tag?]
[attrs txexpr-attrs? @empty]
[elements txexpr-elements? @empty])
txexpr?]
Assemble a @racket[_txexpr] from its parts. If you don't have attributes, but you do have elements, you'll need to pass @racket[empty] as the second argument. Note that unlike @racket[xml->xexpr], if the attribute list is empty, it's not included in the resulting expression.
@examples[#:eval my-eval
(make-txexpr 'div)
(make-txexpr 'div '() '("Hello" (p "World")))
(make-txexpr 'div '[[id "top"]])
(make-txexpr 'div '[[id "top"]] '("Hello" (p "World")))
(define tx '(div [[id "top"]] "Hello" (p "World")))
(make-txexpr (get-tag tx)
(get-attrs tx) (get-elements tx))
]
@defproc[
(can-be-txexpr-attrs?
[v any/c])
boolean?]
Predicate for functions that handle @racket[_txexpr-attrs]. Covers values that are easily converted into pairs of @racket[_attr-key] and @racket[_attr-value]. Namely: single @racket[_xexpr-attr]s, lists of @racket[_xexpr-attr]s (i.e., what you get from @racket[get-attrs]), or interleaved symbols and strings (each pair will be concatenated into a single @racket[_xexpr-attr]).
@deftogether[(
@defproc[
(attrs->hash [x can-be-txexpr-attrs?] ...)
hash?]
@defproc[
(hash->attrs
[h hash?])
txexpr-attrs?]
)]
Convert @racket[_attrs] to an immutable hash, and back again.
@examples[#:eval my-eval
(define tx '(div [[id "top"][class "red"]] "Hello" (p "World")))
(attrs->hash (get-attrs tx))
(hash->attrs '#hash((class . "red") (id . "top")))
]
@defproc[
(attrs-have-key?
[attrs (or/c txexpr-attrs? txexpr?)]
[key can-be-txexpr-attr-key?])
boolean?]
Returns @racket[#t] if the @racket[_attrs] contain a value for the given @racket[_key], @racket[#f] otherwise.
@examples[#:eval my-eval
(define tx '(div [[id "top"][class "red"]] "Hello" (p "World")))
(attrs-have-key? tx 'id)
(attrs-have-key? tx 'grackle)
]
@defproc[
(attr-ref
[tx txexpr?]
[key can-be-txexpr-attr-key?])
txexpr-attr-value?]
Given a @racket[_key], look up the corresponding @racket[_value] in the attributes of a @racket[_txexpr]. Asking for a nonexistent key produces an error.
@examples[#:eval my-eval
(attr-ref tx 'class)
(attr-ref tx 'id)
(attr-ref tx 'nonexistent-key)
]
@defproc[
(attr-set
[tx txexpr?]
[key can-be-txexpr-attr-key?]
[value txexpr-attr-value?])
txexpr?]
Given a @racket[_txexpr], set the value of attribute @racket[_key] to @racket[_value]. The function returns the updated @racket[_txexpr].
@examples[#:eval my-eval
(define tx '(div [[class "red"][id "top"]] "Hello" (p "World")))
(attr-set tx 'id "bottom")
(attr-set tx 'class "blue")
(attr-set (attr-set tx 'id "bottom") 'class "blue")
]
@defproc[
(merge-attrs
[attrs (listof can-be-txexpr-attrs?)] ...)
txexpr-attrs?]
Combine a series of attributes into a single @racket[_txexpr-attrs] item. This function addresses three annoyances that surface in working with txexpr attributes.
@itemlist[#:style 'ordered
@item{You can pass the attributes in multiple forms. See @racket[can-be-txexpr-attrs?] for further details.}
@item{Attributes with the same name are merged, with the later value taking precedence (i.e., @racket[hash] behavior). }
@item{Attributes are sorted in alphabetical order.}]
@examples[#:eval my-eval
(define tx '(div [[id "top"][class "red"]] "Hello" (p "World")))
(define tx-attrs (get-attrs tx))
tx-attrs
(merge-attrs tx-attrs 'editable "true")
(merge-attrs tx-attrs 'id "override-value")
(define my-attr '(id "another-override"))
(merge-attrs tx-attrs my-attr)
(merge-attrs my-attr tx-attrs)
]
@defproc[
(remove-attrs
[tx txexpr?])
txexpr?]
Recursively remove all attributes.
@examples[#:eval my-eval
(define tx '(div [[id "top"]] "Hello" (p [[id "lower"]] "World")))
(remove-attrs tx)
]
@defproc[
(map-elements
[proc procedure?]
[tx txexpr?])
txexpr?]
Recursively apply @racket[_proc] to all elements, leaving tags and attributes alone. Using plain @racket[map] will only process elements at the top level of the current @racket[_txexpr]. Usually that's not what you want.
@examples[#:eval my-eval
(define tx '(div "Hello!" (p "Welcome to" (strong "Mars"))))
(define upcaser (λ(x) (if (string? x) (string-upcase x) x)))
(map upcaser tx)
(map-elements upcaser tx)
]
In practice, most @racket[_xexpr-element]s are strings. But woe befalls those who pass string procedures to @racket[map-elements], because an @racket[_xexpr-element] can be any kind of @racket[xexpr?], and an @racket[xexpr?] is not necessarily a string.
@examples[#:eval my-eval
(define tx '(p "Welcome to" (strong "Mars" amp "Sons")))
(map-elements string-upcase tx)
(define upcaser (λ(x) (if (string? x) (string-upcase x) x)))
(map-elements upcaser tx)
]
@defproc[
(map-elements/exclude
[proc procedure?]
[tx txexpr?]
[exclude-test (txexpr? . -> . boolean?)])
txexpr?]
Like @racket[map-elements], but skips any @racket[_txexprs] that evaluate to @racket[#t] under @racket[_exclude-test]. The @racket[_exclude-test] gets a whole txexpr as input, so it can test any of its parts.
@examples[#:eval my-eval
(define tx '(div "Hello!" (p "Welcome to" (strong "Mars"))))
(define upcaser (λ(x) (if (string? x) (string-upcase x) x)))
(map-elements upcaser tx)
(map-elements/exclude upcaser tx (λ(x) (equal? (get-tag x) 'strong)))
]
Be careful with the wider consequences of exclusion tests. When @racket[_exclude-test] is true, the @racket[_txexpr] is excluded, but so is everything underneath that @racket[_txexpr]. In other words, there is no way to re-include (un-exclude?) elements nested under an excluded element.
@examples[#:eval my-eval
(define tx '(div "Hello!" (p "Welcome to" (strong "Mars"))))
(define upcaser (λ(x) (if (string? x) (string-upcase x) x)))
(map-elements upcaser tx)
(map-elements/exclude upcaser tx (λ(x) (equal? (get-tag x) 'p)))
(map-elements/exclude upcaser tx (λ(x) (equal? (get-tag x) 'div)))
]
@defproc[
(splitf-txexpr
[tx txexpr?]
[pred procedure?])
(values txexpr? (listof txexpr-element?))]
Recursively descend through @racket[_txexpr] and extract all elements that match @racket[_pred]. Returns two values: a @racket[_txexpr] with the matching elements removed, and the list of matching elements. Sort of esoteric, but I've needed it more than once, so here it is.
@examples[#:eval my-eval
(define tx '(div "Wonderful day" (meta "weather" "good") "for a walk"))
(define remove? (λ(x) (and (txexpr? x) (equal? 'meta (get-tag x)))))
(splitf-txexpr tx remove?)
]
@section{License & source code}
This module is licensed under the LGPL.
Source repository at @link["http://github.com/mbutterick/txexpr"]{http://github.com/mbutterick/txexpr}. Suggestions & corrections welcome.

@ -0,0 +1,122 @@
#lang racket/base
(require (for-syntax racket/base))
(require (submod "main.rkt" safe) rackunit)
(define-syntax (values->list stx)
(syntax-case stx ()
[(_ values-expr) #'(call-with-values (λ () values-expr) list)]))
(check-true (txexpr-tag?'foo))
(check-false (txexpr-tag? "foo"))
(check-false (txexpr-tag? 3))
(check-true (txexpr-attr? '(key "value")))
(check-false (txexpr-attr? '(key "value" "another")))
(check-false (txexpr-attr? '(key 0 "value")))
(check-true (txexpr-attrs? '()))
(check-true (txexpr-attrs? '((key "value"))))
(check-true (txexpr-attrs? '((key "value") (foo "bar"))))
(check-false (txexpr-attrs? '((key "value") "foo" "bar"))) ; content, not attr
(check-false (txexpr-attrs? '(key "value"))) ; not a nested list
(check-false (txexpr-attrs? '(("key" "value")))) ; two strings
(check-false (txexpr-attrs? '((key value)))) ; two symbols
(check-true (txexpr-element? "string"))
(check-true (txexpr-element? 'amp))
(check-true (txexpr-element? '(p "string")))
(check-true (txexpr-element? 65)) ;; a valid-char
(check-false (txexpr-element? 0)) ;; not a valid-char
(check-true (txexpr-elements? '("p" "foo" "123")))
(check-true (txexpr-elements? '("p" "foo" 123))) ; includes number
(check-true (txexpr-elements? '(p "foo" "123"))) ; includes symbol
(check-false (txexpr-elements? "foo")) ; not a list
(check-false (txexpr-elements? '(((key "value")) "foo" "bar"))) ; includes attr
(check-false (txexpr-elements? '("foo" "bar" ((key "value"))))) ; malformed
(check-true (txexpr? '(p)))
(check-true (txexpr? '(p "foo" "bar")))
(check-true (txexpr? '(p ((key "value")) "foo" "bar")))
(check-true (txexpr? '(p 123))) ; content is a number
(check-false (txexpr? "foo")) ; not a list with symbol
(check-false (txexpr? '(p "foo" "bar" ((key "value"))))) ; malformed
(check-false (txexpr? '("p" "foo" "bar"))) ; no name
(check-equal? (make-txexpr 'p) '(p))
(check-equal? (make-txexpr 'p '((key "value"))) '(p ((key "value"))))
(check-equal? (make-txexpr 'p null '("foo" "bar")) '(p "foo" "bar"))
(check-equal? (make-txexpr 'p '((key "value")) (list "foo" "bar"))
'(p ((key "value")) "foo" "bar"))
(check-equal? (values->list (txexpr->values '(p)))
(values->list (values 'p null null)))
(check-equal? (values->list (txexpr->values '(p "foo")))
(values->list (values 'p null '("foo"))))
(check-equal? (values->list (txexpr->values '(p ((key "value")))))
(values->list (values 'p '((key "value")) null)))
(check-equal? (values->list (txexpr->values '(p ((key "value")) "foo")))
(values->list (values 'p '((key "value")) '("foo"))))
(check-equal? (values->list (txexpr->values '(p)))
(txexpr->list '(p)))
(check-equal? (values->list (txexpr->values '(p "foo")))
(txexpr->list '(p "foo")))
(check-equal? (values->list (txexpr->values '(p ((key "value")))))
(txexpr->list '(p ((key "value")))))
(check-equal? (values->list (txexpr->values '(p ((key "value")) "foo")))
(txexpr->list '(p ((key "value")) "foo")))
(check-equal? (get-tag '(p ((key "value"))"foo" "bar" (em "square"))) 'p)
(check-equal? (get-attrs '(p ((key "value"))"foo" "bar" (em "square"))) '((key "value")))
(check-equal? (get-elements '(p ((key "value"))"foo" "bar" (em "square")))
'("foo" "bar" (em "square")))
(check-equal? (->txexpr-attr-key "foo") 'foo)
(check-equal? (->txexpr-attr-key 'foo) 'foo)
(check-equal? (->txexpr-attr-value "foo") "foo")
(check-equal? (->txexpr-attr-value 'foo) "foo")
(check-equal? (attrs->hash '((foo "bar"))) '#hash((foo . "bar")))
(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw")) '#hash((foo . "fraw")))
(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw") 'foo "dog") '#hash((foo . "dog")))
(check-equal? (hash->attrs '#hash((foo . "bar")(hee . "haw"))) '((foo "bar")(hee "haw")))
(check-equal? (attr-ref '(p ((foo "bar"))) 'foo) "bar")
(check-equal? (attr-set '(p ((foo "bar"))) 'foo "fraw") '(p ((foo "fraw"))))
(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) 'color))
(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) "color"))
(check-false (attrs-have-key? '((color "red")(shape "circle")) 'nonexistent))
(check-equal? (merge-attrs 'foo "bar") '((foo "bar")))
(check-equal? (merge-attrs '(foo "bar")) '((foo "bar")))
(check-equal? (merge-attrs '((foo "bar"))) '((foo "bar")))
(check-equal? (merge-attrs "foo" 'bar) '((foo "bar")))
(check-equal? (merge-attrs "foo" "bar" "goo" "gar") '((foo "bar")(goo "gar")))
(check-equal? (merge-attrs (merge-attrs "foo" "bar" "goo" "gar") "hee" "haw")
'((foo "bar")(goo "gar")(hee "haw")))
(check-equal? (merge-attrs '((foo "bar")(goo "gar")) "foo" "haw") '((foo "haw")(goo "gar")))
(check-equal? (remove-attrs '(p ((foo "bar")) "hi")) '(p "hi"))
(check-equal? (remove-attrs '(p ((foo "bar")) "hi" (p ((foo "bar")) "hi"))) '(p "hi" (p "hi")))
(check-equal? (map-elements (λ(x) (if (string? x) "boing" x))
'(p "foo" "bar" (em "square")))
'(p "boing" "boing" (em "boing")))
(define split-this-tx '(root (meta "foo" "bar") "hello" "world" (meta "foo2" "bar2")
(em "goodnight" "moon" (meta "foo3" "bar3"))))
(check-equal? (call-with-values (λ() (splitf-txexpr split-this-tx (λ(x) (and (txexpr? x) (equal? 'meta (car x)))))) list)
(list '(root "hello" "world" (em "goodnight" "moon")) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3"))))
(check-equal? (txexpr->html '(root (script "3 > 2") "Why is 3 > 2?"))
"<root><script>3 > 2</script>Why is 3 &gt; 2?</root>")

@ -1,328 +0,0 @@
#lang racket/base
(require racket/match sugar/define sugar/list sugar/coerce
racket/string racket/list
xml
"private/define-provide-safe-match.rkt"
(for-syntax racket/base syntax/parse))
(provide cdata? cdata valid-char? xexpr->string xexpr? comment comment?) ; from xml
(provide empty) ; from racket/list
;; Section 2.2 of XML 1.1
;; (XML 1.0 is slightly different and more restrictive)
;; make private version of my-valid-char to get consistent results with Racket 6.0
(define (my-valid-char? i)
(and (exact-nonnegative-integer? i)
(or (<= #x1 i #xD7FF)
(<= #xE000 i #xFFFD)
(<= #x10000 i #x10FFFF))))
(define (my-xexpr? x)
(or (my-valid-char? x) (xexpr? x) (txexpr? x)))
(define+provide+safe (txexpr? x [allow-long #t])
predicate/c
(match x
[(cons (? txexpr-tag?) rest)
(=> resume)
(let loop ([rest rest])
(match rest
[(list (? my-xexpr?) ...) #true]
[(list (? txexpr-attrs?) elems ...) #:when allow-long (loop elems)]
[_ (resume)]))]
[_ #false]))
(define+provide+safe (txexpr-short? x)
predicate/c
(txexpr? x #false))
(define+provide+safe (txexpr-tag? x)
predicate/c
(symbol? x))
(define+provide+safe (txexpr-attr? x)
predicate/c
(match x
[(list (? txexpr-attr-key?) (? txexpr-attr-value?)) #true]
[_ #false]))
(define+provide+safe (txexpr-element? x)
predicate/c
(my-xexpr? x))
(define+provide+safe (txexpr-attr-key? x)
predicate/c
(symbol? x))
(define+provide+safe (can-be-txexpr-attr-key? x)
predicate/c
(symbolish? x))
(define+provide+safe (txexpr-attr-value? x)
predicate/c
(string? x))
(define+provide+safe (can-be-txexpr-attr-value? x)
predicate/c
(stringish? x))
(define-syntax-rule (define-plural plural-id pred)
(define+provide+safe (plural-id x)
predicate/c
(match x
[(list (? pred) (... ...)) #true]
[_ #false])))
(define-plural txexpr-tags? txexpr-tag?)
(define-plural txexpr-attrs? txexpr-attr?)
(define-plural txexpr-elements? txexpr-element?)
(define-plural txexpr-attr-values? txexpr-attr-value?)
(define-plural list-of-can-be-txexpr-attrs? can-be-txexpr-attrs?)
(define+provide+safe (can-be-txexpr-attrs? x)
predicate/c
(or (can-be-txexpr-attr-key? x)
(can-be-txexpr-attr-value? x)
(txexpr-attr? x)
(txexpr-attrs? x)))
(define (validate-txexpr-attrs tx)
(andmap
(lambda (attr)
(unless (and (list? attr) (eq? 2 (length attr)))
(txexpr-error "attribute" "is not a list of the form '(symbol \"string\")" attr tx))
(unless (symbol? (first attr))
(txexpr-error "attribute key" "is not a symbol" (first attr) tx))
(unless (string? (second attr))
(txexpr-error "attribute value" "is not a string" (second attr) tx))
#t)
(second tx)))
(define (validate-txexpr-elements elems tx)
(andmap
(lambda (e)
(cond
[(or (string? e) (symbol? e) (my-valid-char? e) (cdata? e) (comment? e)) #t]
[(and (list? e) (symbol? (first e)))
(validate-txexpr e)]
[else (txexpr-error "element" "not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)" e tx)]))
elems))
(define (txexpr-error noun has-problem bad tx)
(raise-arguments-error 'validate-txexpr (format "~a ~a" noun has-problem) noun bad "in" tx))
;; is it a named x-expression?
;; Restricting to primitive predicates allows for more specific (helpful) errors
(define+provide+safe (validate-txexpr x)
(any/c . -> . txexpr?)
(unless (list? x) (raise-argument-error 'validate-txexpr "tagged X-expression" x))
(match x
[(list* tag _) #:when (not (symbol? tag))
(txexpr-error "tag" "must be a symbol" tag x)]
[(list* tag (or (? null?) (list (? list?) _ ...)) elems)
(and (validate-txexpr-attrs x) (validate-txexpr-elements elems x) x)]
[(list* tag elems) (and (validate-txexpr-elements elems x) x)]))
(define (txexpr-unsafe tag attrs elements)
(cons tag (match attrs
[(== empty) elements]
[_ (cons attrs elements)])))
(define (txexpr-base func-name tag attrs elements)
(unless (txexpr-tag? tag)
(raise-argument-error func-name "txexpr-tag?" tag))
(unless (txexpr-attrs? attrs)
(raise-argument-error func-name "txexpr-attrs?" attrs))
(unless (txexpr-elements? elements)
(raise-argument-error func-name "txexpr-elements?" elements))
(txexpr-unsafe tag attrs elements))
(define+provide+safe+match (txexpr tag [attrs null] [elements null])
((txexpr-tag?) (txexpr-attrs? txexpr-elements?) . ->* . txexpr?)
(txexpr-base 'txexpr tag attrs elements)
#:match-expander
(syntax-parser
[(_ tag-pat:expr
{~optional attrs-pat:expr #:defaults ([attrs-pat #'_])}
{~optional elements-pat:expr #:defaults ([elements-pat #'_])})
#'(? txexpr? (app txexpr->values tag-pat attrs-pat elements-pat))]))
(define+provide+safe (txexpr* tag [attrs null] . elements)
((txexpr-tag?) (txexpr-attrs?) #:rest txexpr-elements? . ->* . txexpr?)
(txexpr-base 'txexpr* tag attrs elements))
(define make-txexpr txexpr) ; for backward compatability
(provide+safe make-txexpr)
(define+provide+safe (txexpr->values x)
(txexpr? . -> . (values txexpr-tag? txexpr-attrs? txexpr-elements?))
(match x
[(? txexpr-short?) (values (car x) '() (cdr x))]
[_ (values (car x) (cadr x) (cddr x))]))
(define+provide+safe (txexpr->list x)
(txexpr? . -> . list?)
(call-with-values (λ () (txexpr->values x)) list))
;; convenience functions to retrieve only one part of txexpr
(define+provide+safe (get-tag x)
(txexpr? . -> . txexpr-tag?)
(car x))
(define+provide+safe (get-attrs x)
(txexpr? . -> . txexpr-attrs?)
(define-values (tag attrs elements) (txexpr->values x))
attrs)
(define+provide+safe (get-elements x)
(txexpr? . -> . txexpr-elements?)
(define-values (tag attrs elements) (txexpr->values x))
elements)
;; helpers. we are getting a string or symbol
(define+provide+safe (->txexpr-attr-key x)
(can-be-txexpr-attr-key? . -> . txexpr-attr-key?)
(unless (can-be-txexpr-attr-key? x)
(raise-argument-error '->txexpr-attr-key "can-be-txexpr-attr-key?" x))
(->symbol x))
(define+provide+safe (->txexpr-attr-value x)
(can-be-txexpr-attr-value? . -> . txexpr-attr-value?)
(unless (can-be-txexpr-attr-value? x)
(raise-argument-error '->txexpr-attr-value "can-be-txexpr-attr-value?" x))
(->string x))
(define (sublist->attr sublist)
(match sublist
[(list key value) (list (->txexpr-attr-key key) (->txexpr-attr-value value))]))
(define+provide+safe (attrs->hash #:hash-style? [hash-style-priority #f] . items-in)
(() (#:hash-style? boolean?) #:rest (listof can-be-txexpr-attrs?) . ->* . hash-eq?)
;; can be liberal with input because they're all just nested key/value pairs
;; but still need this function to make sure that 'foo and "foo" are treated as the same hash key
(define items (flatten items-in))
(unless (even? (length items))
(raise-argument-error 'attrs->hash "argument list of even length" (length items-in)))
;; hasheq loop will overwrite earlier values with later.
;; but earlier attributes need priority (see https://www.w3.org/TR/xml/#attdecls)
;; thus reverse the pairs.
;; priority-inverted will defeat this assumption, and allow later attributes to overwrite earlier.
(for/hasheq ([sublist (in-list ((if hash-style-priority
values
reverse) (slice-at items 2)))])
(apply values (sublist->attr sublist))))
(define+provide+safe (hash->attrs attr-hash)
(hash? . -> . txexpr-attrs?)
(match (hash->list attr-hash)
[(list (cons ks vs) ...) (map list ks vs)]))
(define+provide+safe (attrs-have-key? x key)
((or/c txexpr-attrs? txexpr?) can-be-txexpr-attr-key? . -> . boolean?)
(match x
[(? txexpr? tx) (and (attr-ref tx key #false) #true)]
[_ (attrs-have-key? (txexpr-unsafe '_ x null) key)]))
(define+provide+safe (attr-set tx key value)
(txexpr? can-be-txexpr-attr-key? can-be-txexpr-attr-value? . -> . txexpr?)
(attr-set* tx key value))
(define+provide+safe (attr-set* tx . kvs)
((txexpr?) #:rest (listof (or/c can-be-txexpr-attr-key? can-be-txexpr-attr-value?)) . ->* . txexpr?)
;; unlike others, this uses hash operations to guarantee that your attr-set
;; is the only one remaining.
(unless (even? (length kvs))
(raise-argument-error 'attr-set* "even number of arguments" kvs))
(define new-attrs (hash->attrs
(apply hash-set* (attrs->hash (get-attrs tx))
(append-map sublist->attr (slice-at kvs 2)))))
(txexpr-base 'attr-set* (get-tag tx) new-attrs (get-elements tx)))
(define+provide+safe (attr-join tx key value)
(txexpr? can-be-txexpr-attr-key? can-be-txexpr-attr-value? . -> . txexpr?)
(define starting-values (string-split (attr-ref tx key "")))
(attr-set tx key (string-join (append starting-values (list (->txexpr-attr-value value))) " ")))
(define no-failure-result (gensym)) ; failure-result might be #false
(define+provide+safe (attr-ref attrs-arg key [failure-result no-failure-result])
(((or/c txexpr? txexpr-attrs?) can-be-txexpr-attr-key?) (any/c) . ->* . any)
(match (assq (->txexpr-attr-key key) (match attrs-arg
[(? txexpr? tx) (get-attrs tx)]
[attrs attrs]))
[(list _ value) value]
[_ (match failure-result
[(? procedure?) (failure-result)]
[(== no-failure-result) (raise-argument-error 'attr-ref "key that exists in attr list" key)]
[_ failure-result])]))
(define+provide+safe (remove-attrs x)
(txexpr? . -> . txexpr?)
(let loop ([x x])
(if (txexpr? x)
(let-values ([(tag attrs elements) (txexpr->values x)])
(txexpr-unsafe tag null (map loop elements)))
x)))
(define+provide+safe (map-elements proc x)
(procedure? txexpr? . -> . txexpr?)
(let loop ([x x])
(proc (if (txexpr? x)
(let-values ([(tag attrs elements) (txexpr->values x)])
(txexpr-unsafe tag attrs (map loop elements)))
x))))
;; function to split tag out of txexpr
(define+provide+safe (splitf-txexpr tx pred [proc (λ (x) #f)])
((txexpr? procedure?) (procedure?) . ->* . (values txexpr? txexpr-elements?))
(unless (txexpr? tx)
(raise-argument-error 'splitf-txexpr "txexpr?" tx))
(define matches null)
(define (extract! x)
(match x
[(? pred)
(set! matches (cons x matches))
(proc x)]
[(? txexpr?) (let-values ([(tag attrs elements) (txexpr->values x)])
(txexpr-unsafe tag attrs (filter values (map extract! elements))))]
[_ x]))
(define tx-extracted (extract! tx)) ;; do this first to fill matches
(values tx-extracted (reverse matches)))
(define+provide+safe (findf*-txexpr tx pred)
(txexpr? procedure? . -> . (or/c #f txexpr-elements?))
(match/values (splitf-txexpr tx pred)
[(_ (? pair? matches)) matches]
[(_ _) #false]))
(define+provide+safe (findf-txexpr tx pred)
(txexpr? procedure? . -> . (or/c #f txexpr-element?))
(match (findf*-txexpr tx pred)
[(cons match _) match]
[_ #false]))
;; don't use "![CDATA[...]]" wrapper in HTML, it's not consistent with the spec
(define (->cdata x) (if (string? x) (cdata #f #f x) x))
;; but treat CDATA strings correctly anyhow, because that's friendly
(define (cdata-string? x)
(and (string? x) (regexp-match #rx"^<!\\[CDATA\\[.*\\]\\]>$" x) #true))
(define comment-pattern #rx"^<!--(.*?)-->$")
(define (string->comment x)
(match (regexp-match comment-pattern x)
[(list _ comment-payload) (comment comment-payload)]
[_ #false]))
(define+provide+safe (xexpr->html x)
(xexpr? . -> . string?)
(xexpr->string
(let loop ([x x])
(cond
[(txexpr? x)
(define-values (tag attrs elements) (txexpr->values x))
(define proc (if (memq tag '(script style)) ->cdata loop))
;; a little faster than `txexpr` since we know the pieces are valid
(txexpr-unsafe tag attrs (map proc elements))]
[(cdata-string? x) (->cdata x)]
[(and (string? x) (string->comment x))]
[else x]))))

@ -1,39 +0,0 @@
#lang racket/base
(require sugar/define racket/match "base.rkt" rackunit)
(define (stringify-attr attr)
(match attr
[(list key val) (string-append (symbol->string key) val)]))
(define (sort-attrs x)
(match x
[(? txexpr?)
(let-values ([(tag attr elements) (txexpr->values x)])
(txexpr tag (sort attr #:key stringify-attr #:cache-keys? #t string<?) (map sort-attrs elements)))]
[_ x]))
(define (txexprs-equal? tx1 tx2)
;; txexprs are deemed equal if they differ only in the ordering of attributes.
;; therefore, to check them, 1) sort their attributes, 2) straight list comparison.
;; use letrec because `define-simple-check` wants an expression in <=6.2
;; `stringify-attr` is needed because comparing attr keys won't work if there are two attrs with same key.
;; so the whole attr is converted into a single string for sorting, which lets the attr value act as a tiebreaker.
;; it doesn't matter that this sort may not be correct (in the sense of a desirable ordering)
;; it just needs to be stable (e.g., a certain set of attrs will always sort the same way)
(equal? (sort-attrs tx1) (sort-attrs tx2)))
(define+provide+safe (attrs-equal? x1 x2)
((or/c txexpr-attrs? txexpr?) (or/c txexpr-attrs? txexpr?) . -> . boolean?)
(apply txexprs-equal? (map (λ (x) `(_ ,(if (txexpr-attrs? x) x (get-attrs x)))) (list x1 x2))))
(provide+safe check-txexprs-equal?)
(define-simple-check (check-txexprs-equal? tx1 tx2)
(txexprs-equal? tx1 tx2))
(module+ test
(check-txexprs-equal? '(p ((b "foo")(a "bar")) (span ((d "foo")(c "bar"))))
'(p ((a "bar")(b "foo")) (span ((c "bar")(d "foo")))))
;; two attrs with same key
(check-txexprs-equal? '(p ((a "foo")(a "bar")))
'(p ((a "bar")(a "foo")))))

@ -1,4 +0,0 @@
#lang info
(define scribblings '(("scribblings/txexpr.scrbl" ())))
(define compile-omit-paths '("test/tests.rkt"))

@ -1,14 +0,0 @@
#lang racket/base
(define-syntax-rule (r+p MODNAME ...)
(begin
(begin
(require MODNAME)
(provide (all-from-out MODNAME))
(module+ safe
(require (submod MODNAME safe))
(provide (all-from-out (submod MODNAME safe))))) ...))
(r+p "base.rkt"
"stx.rkt"
"check.rkt")

@ -1,43 +0,0 @@
#lang racket/base
(provide txexpr?/recur
txexpr->values/attrs?)
(require racket/list)
;; A [TXcontainer T A E] is one of:
;; - (List* T A (Listof E))
;; - (Lxst* T (Listof E))
;; Where A and E are disjoint.
;; txexpr?/recur :
;; Any
;; [Any -> Bool : T]
;; [Any -> Bool : #:+ (and A (! E)) #:- (! A)]
;; [Any -> Bool : #:+ (and E (! A)) #:- (! E)]
;; ->
;; Bool
;; : [TXcontainer T A E]
;; the attrs? predicate and the element? predicate should be disjoint
(define (txexpr?/recur v tag? attrs? element?)
(and (list? v)
(not (empty? v))
(tag? (first v))
(cond [(and (not (empty? (rest v)))
(attrs? (second v)))
(andmap element? (rest (rest v)))]
[else
(andmap element? (rest v))])))
;; txexpr->values/attrs? :
;; [TXcontainer T A E]
;; [Any -> Bool : #:+ (and A (! E)) #:- (! A)]
;; ->
;; (values T A (Listof E))
(define (txexpr->values/attrs? tx attrs?)
(cond [(and (not (empty? (rest tx)))
(attrs? (second tx)))
(values (first tx) (second tx) (rest (rest tx)))]
[else
(values (first tx) '() (rest tx))]))

@ -1,82 +0,0 @@
#lang racket/base
(provide define+provide+safe+match)
(require racket/match
(for-syntax racket/base
racket/syntax
syntax/parse
syntax/stx
version/utils))
;; (define+provide+safe+match name-id
;; contract-expr
;; value-expr
;; #:match-expander
;; match-transformer-expr)
;;
;; (define+provide+safe+match (head . args)
;; contract-expr
;; value-body-expr
;; ...+
;; #:match-expander
;; match-transformer-expr)
(begin-for-syntax
;; Identifier -> [Syntax -> Syntax]
(define ((variable-like-transformer id) stx)
(cond
[(identifier? stx)
; id, but with the source location of stx
(datum->syntax id (syntax-e id) stx id)]
[(stx-pair? stx)
(datum->syntax stx (cons id (stx-cdr stx)) stx stx)])))
(define-syntax define+provide+safe+match
(λ (stx)
(syntax-parse stx
[(d (head . args)
contract:expr
value-body:expr ...+
#:match-expander match-transformer:expr)
#:with fn-expr (syntax/loc stx (λ args value-body ...))
(syntax/loc stx
(d head contract fn-expr #:match-expander match-transformer))]
[(_ name:id
contract:expr
value:expr
#:match-expander match-transformer:expr)
#:with internal-name (generate-temporary #'name)
#:with contract-name (generate-temporary #'name)
#:with make-name-match-transformer (generate-temporary #'name)
#:with [name-for-blame ...]
(cond [(version<=? "6.8" (version)) #'[#:name-for-blame name]]
[else #'[]])
#'(begin
(define internal-name (let ([name value]) name))
(begin-for-syntax
(define (make-name-match-transformer name)
(with-syntax ([name name]) match-transformer)))
(define-match-expander name
(make-name-match-transformer (quote-syntax internal-name))
(variable-like-transformer (quote-syntax internal-name)))
(provide name)
(module+ safe
(require racket/contract/base)
(define-module-boundary-contract contract-name internal-name contract
name-for-blame ...)
(define-match-expander name
(make-name-match-transformer (quote-syntax contract-name))
(variable-like-transformer (quote-syntax contract-name)))
(provide name)))])))

@ -1,688 +0,0 @@
#lang scribble/manual
@; for documentation purposes, use the xexpr? from xml.
@; the one in txexpr is just to patch over an issue with
@; `valid-char?` in Racket 6.
@(require scribble/eval
(for-label racket txexpr txexpr/stx xml rackunit))
@(define my-eval (make-base-eval))
@(my-eval `(require racket/match txexpr xml rackunit))
@title{txexpr: Tagged X-expressions}
@author[(author+email "Matthew Butterick" "mb@mbtype.com")]
@defmodule[#:multi (txexpr (submod txexpr safe))]
A set of small but handy functions for improving the readability and reliability of programs that operate on tagged X-expressions (for short, @italic{txexpr}s).
@section{Installation}
At the command line:
@verbatim{raco pkg install txexpr}
After that, you can update the package from the command line:
@verbatim{raco pkg update txexpr}
@section{Importing the module}
The module can be invoked two ways: fast or safe.
Fast mode is the default, which you get by importing the module in the usual way: @code{(require txexpr)}.
Safe mode enables the function contracts documented below. Use safe mode by importing the module as @code{(require (submod txexpr safe))}.
@section[#:tag "what-is-a-txexpr"]{Whats a tagged X-expression (aka txexpr)?}
It's an X-expression with the following grammar:
@racketgrammar*[
#:literals (cons list symbol? string? xexpr?)
[txexpr (list tag (list attr ...) element ...)
(cons tag (list element ...))]
[tag symbol?]
[attr (list key value)]
[key symbol?]
[value string?]
[element xexpr?]
]
A tagged X-expression — @italic{txexpr} for short — is a list with a symbol in the first position — the @italic{tag} — followed by a series of @italic{elements}, which are other X-expressions. Optionally, a txexpr can have a list of @italic{attributes} in the second position.
@examples[#:eval my-eval
(txexpr? '(span "Brennan" "Dale"))
(txexpr? '(span "Brennan" (em "Richard") "Dale"))
(txexpr? '(span ((class "hidden")(id "names")) "Brennan" "Dale"))
(txexpr? '(span lt gt amp))
(txexpr? '("We really" "should have" "a tag"))
(txexpr? '(span ((class not-quoted)) "Brennan"))
(txexpr? '(span (class "hidden") "Brennan" "Dale"))
]
The last one is a common mistake. Because the keyvalue pair is not enclosed in a @tech[#:doc '(lib "scribblings/guide/guide.scrbl")]{list}, it's interpreted as a nested txexpr within the first txexpr, as you may not find out until you try to read its attributes:
@examples[#:eval my-eval
(get-attrs '(span (class "hidden") "Brennan" "Dale"))
(get-elements '(span (class "hidden") "Brennan" "Dale"))
]
Tagged X-expressions are most commonly found in HTML & XML documents. Though the notation is different in Racket, the data structure is identical:
@examples[#:eval my-eval
(xexpr->string '(span ((id "names")) "Brennan" (em "Richard") "Dale"))
(string->xexpr "<span id=\"names\">Brennan<em>Richard</em>Dale</span>")
]
After converting to and from HTML, we get back the original X-expression. Well, almost. Per its usual practice, @racket[string->xexpr] added an empty attribute list after @racket[em]. This is benign — an empty attribute list can be omitted with no change in meaning, or vice versa.
@section{Why not just use @exec{match}, @exec{quasiquote}, and so on?}
If you prefer those, please do. But I've found two benefits to using module functions:
@bold{Readability.} In code that already has a lot of matching and quasiquoting going on, these functions make it easy to see where & how txexprs are being used.
@bold{Reliability.} Because txexprs come in two close but not quite equal forms, careful coders will always have to take both cases into account.
The programming is trivial, but the annoyance is real.
@section{Predicates}
@deftogether[(
@defproc[
(txexpr?
[v any/c])
boolean?]
@defproc[
(txexpr-tag?
[v any/c])
boolean?]
@defproc[
(txexpr-attr?
[v any/c])
boolean?]
@defproc[
(txexpr-attr-key?
[v any/c])
boolean?]
@defproc[
(txexpr-attr-value?
[v any/c])
boolean?]
@defproc[
(txexpr-element?
[v any/c])
boolean?]
)]
Predicates for @racket[_txexpr]s that implement this grammar:
@racketgrammar*[
#:literals (cons list symbol? string? xexpr?)
[txexpr (list tag (list attr ...) element ...)
(cons tag (list element ...))]
[tag symbol?]
[attr (list key value)]
[key symbol?]
[value string?]
[element xexpr?]
]
@deftogether[(
@defproc[
(txexpr-tags?
[v any/c])
boolean?]
@defproc[
(txexpr-attrs?
[v any/c])
boolean?]
@defproc[
(txexpr-elements?
[v any/c])
boolean?]
)]
Predicates equivalent to a list of @code{txexpr-tag?}, @code{txexpr-attr?}, or @code{txexpr-element?}, respectively.
@deftogether[(
@defproc[
(can-be-txexpr-attr-key?
[v any/c])
boolean?]
@defproc[
(can-be-txexpr-attr-value?
[v any/c])
boolean?]
)]
Predicates for input arguments that can be trivially converted to an attribute @racket[_key] or @racket[_value] with the associated conversion functions.
@examples[#:eval my-eval
(can-be-txexpr-attr-key? 'symbol)
(can-be-txexpr-attr-key? "string-val")
(can-be-txexpr-attr-key? (list 1 2 3))
(can-be-txexpr-attr-value? 'symbol)
(can-be-txexpr-attr-value? "string-val")
(can-be-txexpr-attr-value? (list 1 2 3))
]
@defproc[
(can-be-txexpr-attrs?
[v any/c])
boolean?]
Predicate for functions that handle @racket[_txexpr-attrs]. Covers values that are easily converted into pairs of @racket[_attr-key] and @racket[_attr-value]. Namely: single @racket[_xexpr-attr]s, lists of @racket[_xexpr-attr]s (i.e., what you get from @racket[get-attrs]), or interleaved symbols and strings (each pair will be concatenated into a single @racket[_xexpr-attr]).
@defproc[
(validate-txexpr
[possible-txexpr any/c])
txexpr?]
Like @racket[txexpr?], but raise a descriptive error pinpointing the first problem encountered if @racket[_possible-txexpr] is invalid, and otherwise return @racket[_possible-txexpr] itself.
@examples[#:eval my-eval
(validate-txexpr 'root)
(validate-txexpr '(root))
(validate-txexpr '(root ((id "top")(class 42))))
(validate-txexpr '(root ((id "top")(class "42"))))
(validate-txexpr '(root ((id "top")(class "42")) ("hi")))
(validate-txexpr '(root ((id "top")(class "42")) "hi"))
(validate-txexpr '(root (p "Hello " (span [[class "inner"]] (1 2 3)))))
(validate-txexpr `(root (p "Look out" (span ,(void)) (1 2 3))))
]
@section{Making & breaking}
@defproc[
(txexpr
[tag txexpr-tag?]
[attrs txexpr-attrs? @empty]
[elements txexpr-elements? @empty])
txexpr?]
Assemble a @racket[_txexpr] from its parts. If you don't have attributes, but you do have elements, you'll need to pass @racket[empty] (or @racket[null] or @racket['()]) as the second argument. Note that unlike @racket[xml->xexpr], if the attribute list is empty, it's not included in the resulting expression.
@examples[#:eval my-eval
(txexpr 'div)
(txexpr 'div '() '("Hello" (p "World")))
(txexpr 'div '((id "top")))
(txexpr 'div '((id "top")) '("Hello" (p "World")))
(define tx '(div ((id "top")) "Hello" (p "World")))
(txexpr (get-tag tx)
(get-attrs tx) (get-elements tx))
]
The @racket[txexpr] form can also be used as a match pattern:
@examples[#:eval my-eval
(match '(div)
[(txexpr tag attrs elems)
(values tag attrs elems)])
(match '(div "Hello" (p "World"))
[(txexpr tag attrs elems)
(values tag attrs elems)])
(match '(div "Hello" (p "World"))
[(txexpr 'div attrs1 (list elems1 ... (txexpr 'p attrs2 elems2)))
(values attrs1 elems1 attrs2 elems2)])
(match '(div ((id "top")) "Hello" (p "World"))
[(txexpr 'div attrs1 (list elems1 ... (txexpr 'p attrs2 elems2)))
(values attrs1 elems1 attrs2 elems2)])
]
@defproc[
(txexpr*
[tag txexpr-tag?]
[attrs txexpr-attrs? @empty]
[element txexpr-element?] ...)
txexpr?]
Like @racket[txexpr], but takes an indefinite number of @racket[_element] arguments, which together are treated as the list of elements for the resulting @racket[_txexpr]. A notational convenience.
@examples[#:eval my-eval
(txexpr* 'div)
(txexpr* 'div '() "Hello" '(p "World"))
(txexpr* 'div '((id "top")))
(txexpr* 'div '((id "top")) "Hello" '(p "World"))
(define tx '(div ((id "top")) "Hello" (p "World")))
(apply txexpr* (get-tag tx)
(get-attrs tx) (get-elements tx))
]
@deftogether[(
@defproc[
(get-tag
[tx txexpr?])
txexpr-tag?]
@defproc[
(get-attrs
[tx txexpr?])
txexpr-attr?]
@defproc[
(get-elements
[tx txexpr?])
(listof txexpr-element?)]
)]
Accessor functions for the individual pieces of a @racket[_txexpr].
@examples[#:eval my-eval
(get-tag '(div ((id "top")) "Hello" (p "World")))
(get-attrs '(div ((id "top")) "Hello" (p "World")))
(get-elements '(div ((id "top")) "Hello" (p "World")))
]
@deftogether[(
@defproc[
(txexpr->values
[tx txexpr?])
(values txexpr-tag? txexpr-attrs? txexpr-elements?)]
@defproc[
(txexpr->list
[tx txexpr?])
(list txexpr-tag?
txexpr-attrs?
txexpr-elements?)]
)]
Dissolve a @racket[_txexpr] into its components. @racket[txexpr->values] returns the components as multiple values; @racket[txexpr->list] returns them in a list.
@examples[#:eval my-eval
(txexpr->values '(div))
(txexpr->values '(div "Hello" (p "World")))
(txexpr->values '(div ((id "top")) "Hello" (p "World")))
(txexpr->list '(div))
(txexpr->list '(div "Hello" (p "World")))
(txexpr->list '(div ((id "top")) "Hello" (p "World")))
]
@section{Attributes}
@deftogether[(
@defproc[
(attrs->hash
[#:hash-style? hash-style-priority boolean? #f]
[x can-be-txexpr-attrs?] ...)
hash-eq?]
@defproc[
(hash->attrs
[h hash?])
txexpr-attrs?]
)]
Convert @racket[_attrs] to an immutable hash, and back again. Following the convention specified for @link["https://www.w3.org/TR/xml/#attdecls"]{XML parsers}, the @italic{first} appearance of an attribute name binds the value — later attributes with the same name are ignored. If you prefer the typical @racket[hash] behavior where later values override earlier ones, set @racket[#:hash-style?] to @racket[#t].
@examples[#:eval my-eval
(define tx '(div ((id "top")(class "red")) "Hello" (p "World")))
(attrs->hash (get-attrs tx))
(hash->attrs '#hasheq((class . "red") (id . "top")))
(attrs->hash '((color "blue")(color "green")))
(attrs->hash #:hash-style? #t '((color "blue")(color "green")))
]
@defproc[
(attrs-have-key?
[attrs (or/c txexpr-attrs? txexpr?)]
[key can-be-txexpr-attr-key?])
boolean?]
Return @racket[#t] if the @racket[_attrs] contain a value for the given @racket[_key], @racket[#f] otherwise.
@examples[#:eval my-eval
(define tx '(div ((id "top")(class "red")) "Hello" (p "World")))
(attrs-have-key? tx 'id)
(attrs-have-key? tx 'grackle)
]
@defproc[
(attrs-equal?
[attrs (or/c txexpr-attrs? txexpr?)]
[other-attrs (or/c txexpr-attrs? txexpr?)])
boolean?]
Return @racket[#t] if @racket[_attrs] and @racket[_other-attrs] contain the same keys and values, @racket[#f] otherwise. The order of attributes is irrelevant. (If order matters to you, use good old @racket[equal?] instead.)
@examples[#:eval my-eval
(define tx1 '(div ((id "top")(class "red")) "Hello"))
(define tx2 '(p ((class "red")(id "top")) "Hello"))
(define tx3 '(p ((id "bottom")(class "red")) "Hello"))
(attrs-equal? tx1 tx2)
(attrs-equal? tx1 tx3)
(equal? tx1 tx2)
(equal? tx1 tx3)
]
@defproc[
(attr-ref
[attrs (or/c txexpr-attrs? txexpr?)]
[key can-be-txexpr-attr-key?]
[failure-result any/c (λ _ (raise (make-exn:fail:contract ....)))
])
any]
Given a @racket[_key], return the corresponding @racket[_value] from @racket[_attrs]. By default, asking for a nonexistent key produces an error. But if a value or procedure is provided as the @racket[_failure-result], evaluate and return that instead.
@examples[#:eval my-eval
(define tx '(div ((id "top")(class "red")) "Hello" (p "World")))
(attr-ref tx 'class)
(attr-ref tx 'id)
(attr-ref tx 'nonexistent-key)
(attr-ref tx 'nonexistent-key "forty-two")
(attr-ref tx 'nonexistent-key (λ _ (* 6 7)))
(define attrs '((id "top")(class "red")))
(attr-ref attrs 'class)
(attr-ref attrs 'id)
(attr-ref attrs 'nonexistent-key)
]
@deftogether[(
@defproc[
(attr-set
[tx txexpr?]
[key can-be-txexpr-attr-key?]
[value can-be-txexpr-attr-value?])
txexpr?]
@defproc[
(attr-set*
[tx txexpr?]
[key can-be-txexpr-attr-key?]
[value can-be-txexpr-attr-value?] ... ... )
txexpr?]
)]
Set the value of attribute @racket[_key] to @racket[_value] in @racket[_txexpr]. Return the updated @racket[_txexpr]. Duplicate attributes, if they exist, are resolved using @racket[attrs->hash]. @racket[attr-set] only accepts one key and one value; @racket[attr-set*] accepts any number.
@examples[#:eval my-eval
(define tx '(div ((class "red")(id "top")) "Hello" (p "World")))
(attr-set tx 'id "bottom")
(attr-set tx 'class "blue")
(attr-set (attr-set tx 'id "bottom") 'class "blue")
(define tx '(div "Hello"))
(attr-set* tx 'id "bottom" 'class "blue")
]
@defproc[
(attr-join
[tx txexpr?]
[key can-be-txexpr-attr-key?]
[value can-be-txexpr-attr-value?])
txexpr?]
Given a @racket[_txexpr], append attribute @racket[_key] with @racket[_value]. Return the updated @racket[_txexpr]. If @racket[_key] doesn't already exist, then add a new attribute (i.e., behave like @racket[attr-set]).
@examples[#:eval my-eval
(define tx '(div ((class "red")) "Hello"))
(attr-join tx 'class "small")
(attr-join tx 'klass "small")
]
@defproc[
(remove-attrs
[tx txexpr?])
txexpr?]
Recursively remove all attributes from @racket[_tx].
@examples[#:eval my-eval
(define tx '(div ((id "top")) "Hello" (p ((id "lower")) "World")))
(remove-attrs tx)
]
@section{Strange magic}
@defproc[
(map-elements
[proc procedure?]
[tx txexpr?])
txexpr?]
Recursively apply @racket[_proc] to all elements, leaving tags and attributes alone. Using plain @racket[map] will only process elements at the top level of @racket[_tx]. Usually that's not what you want.
@examples[#:eval my-eval
(define tx '(div "Hello!" (p "Welcome to" (strong "Mars"))))
(define upcaser (λ (x) (if (string? x) (string-upcase x) x)))
(map upcaser tx)
(map-elements upcaser tx)
]
In practice, most @racket[_txexpr-element]s are strings. But it's unwise to pass string-only procedures to @racket[map-elements], because an @racket[_txexpr-element] can be any kind of @racket[xexpr?], and an @racket[xexpr?] is not necessarily a string.
@examples[#:eval my-eval
(define tx '(p "Welcome to" (strong "Mars" amp "Sons")))
(map-elements string-upcase tx)
(define upcaser (λ (x) (if (string? x) (string-upcase x) x)))
(map-elements upcaser tx)
]
@defproc[
(splitf-txexpr
[tx txexpr?]
[pred procedure?]
[replace-proc procedure? (λ (x) #f)])
(values txexpr? (listof txexpr-element?))]
Recursively descend through @racket[_txexpr] and extract all elements that match @racket[_pred]. Returns two values: a @racket[_txexpr] with the matching elements removed, and the list of matching elements. Sort of esoteric, but I've needed it more than once, so here it is.
@examples[#:eval my-eval
(define tx '(div "Wonderful day" (meta "weather" "good") "for a walk"))
(define is-meta? (λ (x) (and (txexpr? x) (equal? 'meta (get-tag x)))))
(splitf-txexpr tx is-meta?)
]
Ordinarily, the result of the split operation is to remove the elements that match @racket[_pred]. But you can change this behavior with the optional @racket[_replace-proc] argument.
@examples[#:eval my-eval
(define tx '(div "Wonderful day" (meta "weather" "good") "for a walk"))
(define is-meta? (λ (x) (and (txexpr? x) (equal? 'meta (get-tag x)))))
(define replace-meta (λ (x) '(em "meta was here")))
(splitf-txexpr tx is-meta? replace-meta)
]
@deftogether[(
@defproc[
(findf-txexpr
[tx txexpr?]
[pred procedure?])
(or/c #f txexpr-element?)]
@defproc[
(findf*-txexpr
[tx txexpr?]
[pred procedure?])
(or/c #f (listof txexpr-element?))]
)]
Like @racket[splitf-txexpr], but only retrieve the elements that match @racket[_pred]. @racket[findf*-txexpr] retrieves all results; @racket[findf-txexpr] only the first. In both cases, if there are no matches, you get @racket[#f].
@examples[#:eval my-eval
(define tx '(div "Wonderful day" (meta "weather" "good")
"for a walk" (meta "dog" "Roxy")))
(define is-meta? (λ (x) (and (txexpr? x) (eq? 'meta (get-tag x)))))
(findf*-txexpr tx is-meta?)
(findf-txexpr tx is-meta?)
(define is-zimzam? (λ (x) (and (txexpr? x) (eq? 'zimzam (get-tag x)))))
(findf*-txexpr tx is-zimzam?)
(findf-txexpr tx is-zimzam?)
]
@section{HTML conversion}
@defproc[
(xexpr->html
[x xexpr?])
string?]
Convert @racket[_x] to an HTML string. Better than @racket[xexpr->string] because consistent with the HTML spec, it will skip the content of @code{script} or @code{style} blocks. For convenience, this function will take any X-expression, not just tagged X-expressions.
@examples[#:eval my-eval
(define tx '(root (script "3 > 2") "Why is 3 > 2?"))
(xexpr->string tx)
(xexpr->html tx)
(map xexpr->html (list "string" 'entity 65))
]
@section{Unit testing}
@defproc[
(check-txexprs-equal?
[tx1 txexpr?]
[tx2 txexpr?])
void?]
Designed to be used with @racketmodname[rackunit]. Check whether @racket[_tx1] and @racket[_tx2] are @racket[equal?] except for ordering of attributes (which ordinarily has no semantic significance). Return @racket[void] if so, otherwise raise a check failure.
@examples[#:eval my-eval
(define tx1 '(div ((attr-a "foo")(attr-z "bar"))))
(define tx2 '(div ((attr-z "bar")(attr-a "foo"))))
(parameterize ([current-check-handler (λ _ (display "not "))])
(display "txexprs are ")
(check-txexprs-equal? tx1 tx2)
(displayln "equal"))
]
If ordering of attributes is relevant to your test, then just use @racket[check-equal?] as usual.
@examples[#:eval my-eval
(define tx1 '(div ((attr-a "foo")(attr-z "bar"))))
(define tx2 '(div ((attr-z "bar")(attr-a "foo"))))
(parameterize ([current-check-handler (λ _ (display "not "))])
(display "txexprs are ")
(check-equal? tx1 tx2)
(displayln "equal"))
]
@section{Syntax Versions of X-expressions}
@(define stx-eval (make-base-eval))
@(stx-eval `(require txexpr txexpr/stx xml rackunit))
@defmodule[txexpr/stx]{
This module provides functions for destructuring TX-expressions
that might be wrapped in syntax objects.
}
@defproc[(stx-xexpr? [v any/c]) boolean?]{
A predicate for X-expressions that might be wrapped in syntax
(or have parts of them wrapped in syntax). It returns
@racket[#true] for values that would become normal X-expressions
with @racket[(syntax->datum (datum->syntax #f v))].
@examples[#:eval stx-eval
(stx-xexpr? "A leaf on the wind")
(stx-xexpr? #'"A leaf in a bin")
(stx-xexpr? '(div ((id "top")) "Hello" (p "World")))
(stx-xexpr? #'(div ((id "top")) "Hello" (p "World")))
(stx-xexpr? `(div ((id ,#'"top")) "Hello" ,#'(p "World")))
]}
@defproc[(stx-txexpr? [v any/c]) boolean?]{
A predicate for Tagged X-expressions that might be wrapped in
syntax. It returns @racket[#true] for values that become one
of these with @racket[(syntax->datum (datum->syntax #f v))]:
@racketgrammar*[
#:literals (list)
[txexpr (list tag attrs xexpr ...)
(list tag xexpr ...)]
]
@examples[#:eval stx-eval
(stx-txexpr? "A block at the top")
(stx-txexpr? '(div ((id "top")) "A block beneath a" (p "tag")))
(stx-txexpr? #'(div ((id "top")) "A block beneath a" (p "tag")))
(stx-txexpr? #'(div "A block beneath a" (p "tag")))
]}
@deftogether[[
@defproc[(stx-txexpr-tag? [v any/c]) boolean?]
@defproc[(stx-txexpr-attrs? [v any/c]) boolean?]
]]{
Predicates for sub-parts of TX-expressions that might be wrapped
in syntax. There return @racket[#true] for values that become
@racket[txexpr-tag?]s or @racket[txexpr-attrs?]s when unwrapped
with @racket[(syntax->datum (datum->syntax #f v))].
@examples[#:eval stx-eval
(stx-txexpr-tag? 'div)
(stx-txexpr-tag? #'div)
(stx-txexpr-tag? 'analogous)
(stx-txexpr-tag? #'analogous)
(stx-txexpr-attrs? '())
(stx-txexpr-attrs? #'())
(stx-txexpr-attrs? '((id "top") (style "color: blue")))
(stx-txexpr-attrs? #'((id "top") (style "color: blue")))
(stx-txexpr-attrs? `((id "top") (style ,#'"color: blue")))
]}
@deftogether[[
@defproc[(stx-txexpr-tag [tx stx-txexpr?]) stx-txexpr-tag?]
@defproc[(stx-txexpr-attrs [tx stx-txexpr?]) stx-txexpr-attrs?]
@defproc[(stx-txexpr-elements [tx stx-txexpr?]) (listof stx-txexpr?)]
]]{
Accessor functions for the tag, attributes, and elements of a
txexpr that might be wrapped in syntax. Note that these functions
work whether the input is wrapped in syntax or not, and that
the results may or may not be wrapped in syntax, depending on
whether the input was wrapped.
@examples[#:eval stx-eval
(define tx1 '(div ((id "top")) "Hello" (p "World")))
(define tx2 #'(div ((id "top")) "Hello" (p "World")))
(stx-txexpr-tag tx1)
(stx-txexpr-tag tx2)
(stx-txexpr-attrs tx1)
(stx-txexpr-attrs tx2)
(stx-txexpr-elements tx1)
(stx-txexpr-elements tx2)
]}
@deftogether[[
@defproc[(stx-txexpr->values [tx stx-txexpr?])
(values stx-txexpr-tag? stx-txexpr-attrs? (listof stx-txexpr?))]
@defproc[(stx-txexpr->list [tx stx-txexpr?])
(list/c stx-txexpr-tag? stx-txexpr-attrs? (listof stx-txexpr?))]
]]{
These functions break up a TX-expression into its components.
@racket[stx-txexpr->values] returns them as three values, and
@racket[stx-txexpr->list] returns them as a three-element list.
@examples[#:eval stx-eval
(stx-txexpr->values '(div))
(stx-txexpr->list '(div))
(stx-txexpr->values #'(div))
(stx-txexpr->values #'(div "Hello" (p "World")))
(stx-txexpr->values #'(div ((id "top")) "Hello" (p "World")))
(stx-txexpr->values `(div ((id "top")) "Hello" ,#'(p "World")))
]}
@section{License & source code}
This module is licensed under the LGPL.
Source repository at @link["http://github.com/mbutterick/txexpr"]{http://github.com/mbutterick/txexpr}. Suggestions & corrections welcome.

@ -1,129 +0,0 @@
#lang racket/base
(provide stx-xexpr?
stx-txexpr?
stx-txexpr-tag?
stx-txexpr-attrs?
stx-txexpr->values
stx-txexpr->list
stx-txexpr-tag
stx-txexpr-attrs
stx-txexpr-elements)
(require syntax/stx
xml
"base.rkt"
"private/container.rkt")
;; ---------------------------------------------------------
;; Data Definitions
;; A [Stx E] is one of:
;; - (Syntaxof E)
;; - E
;; A StxXexpr is a [Stx XexprE]
;; A StxTXexpr is a [Stx TXexprE]
;; A StxTag is a [Stx Symbol]
;; A StxAttrs is a (StxListof (StxList [Stx Symbol] [Stx String]))
;; A StxElements is a (StxListof StxXexpr)
;; A XexprE is one of:
;; - String
;; - TXexprE
;; - Symbol ; for example 'nbsp representing `&nbsp;`
;; - ValidChar ; for example #x20 representing `&#x20;`
;; - CData ; an instance of the `cdata` structure type from `xml`
;; - Misc ; an instance of the `comment` or `p-i` structure types
;; A TXexprE is one of:
;; - (list* StxTag StxAttrs StxElements)
;; - (list* StxTag StxElements)
;; The types `StxAttrs` and `StxXexpr` are disjoint, as they
;; need to be for this to be unambiguous.
;; ---------------------------------------------------------
;; Predicates
;; Any -> Bool
(define (stx-xexpr? v)
(stx-xexpr?/recur v stx-xexpr?))
;; Any -> Bool
(define (stx-txexpr? v)
(stx-txexpr?/recur v stx-xexpr?))
;; Any [Any -> Bool] -> Bool
(define (stx-xexpr?/recur v rec)
(cond
[(syntax? v) (stx-xexpr?/recur (syntax-e v) rec)]
[(pair? v) (stx-txexpr?/recur v rec)]
[else (xexpr?/recur v rec)]))
;; Any [Any -> Bool] -> Bool
;; the `rec` predicate should not overlap with `txexpr-attrs?`
(define (xexpr?/recur v rec)
(cond
[(pair? v) (txexpr?/recur v txexpr-tag? txexpr-attrs? rec)]
[(string? v) #true]
[(symbol? v) #true]
[(integer? v) (valid-char? v)]
[(cdata? v) #true]
[(comment? v) #true]
[(p-i? v) #true]
[else #false]))
;; Any [Any -> Bool] -> Bool
;; the `rec` predicate should not overlap with
;; `stx-txexpr-attrs?`
(define (stx-txexpr?/recur v rec)
;; Even if it's not stx, the cdr or cddr might be syntax.
;; This flattens it so that the cdd...r is always a pair or empty.
(define lst (stx->list v))
(and lst (txexpr?/recur lst stx-txexpr-tag? stx-txexpr-attrs? rec)))
;; Any -> Bool
(define (stx-txexpr-tag? v)
(cond
[(syntax? v) (txexpr-tag? (syntax-e v))]
[else (txexpr-tag? v)]))
;; Any -> Bool
(define (stx-txexpr-attrs? v)
(txexpr-attrs? (syntax->datum (datum->syntax #f v))))
;; ---------------------------------------------------------
;; Accessors
;; StxTxexpr -> (values StxTag StxAttrs StxElements)
(define (stx-txexpr->values v)
(txexpr->values/attrs? (stx->list v) stx-txexpr-attrs?))
;; StxTxexpr -> (List StxTag StxAttrs StxElements)
(define (stx-txexpr->list v)
(define-values [tag attrs elements] (stx-txexpr->values v))
(list tag attrs elements))
;; StxTxexpr -> StxTag
(define (stx-txexpr-tag v)
(define-values [tag attrs elements] (stx-txexpr->values v))
tag)
;; StxTxexpr -> StxAttrs
(define (stx-txexpr-attrs v)
(define-values [tag attrs elements] (stx-txexpr->values v))
attrs)
;; StxTxexpr -> StxElements
(define (stx-txexpr-elements v)
(define-values [tag attrs elements] (stx-txexpr->values v))
elements)
;; ---------------------------------------------------------
(module+ safe
(provide (all-defined-out)))

@ -1,63 +0,0 @@
#lang racket/base
(provide values->list
check-values=?
check/values)
(require rackunit
(for-syntax racket/base))
;; Takes an expression producing an unknown number of values
;; and wraps them all in a list.
(define-syntax-rule (values->list values-expr)
(call-with-values (λ () values-expr) list))
;; Checks that two expressions (each producing an unknown
;; number of values until evaluated) produce the same number
;; of values, and that the values are equal.
(define-syntax check-values=?
(lambda (stx)
(syntax-case stx []
[(_ actual-expr expected-expr)
(syntax/loc stx
(check/values check-equal? actual-expr expected-expr))])))
(define-syntax check/values
(lambda (stx)
(syntax-case stx []
[(_ check-form actual-expr expected-expr)
(syntax/loc stx
(check-form (vs actual-expr) (vs expected-expr)))])))
;; Takes an expression producing an unknown number of values
;; and wraps them in a "fake-values" structure that can be
;; compared with other fake-values structures for equality,
;; and can be printed to look like a call to `values`.
(define-syntax-rule (vs values-expr)
(fake-values (values->list values-expr)))
;; if make-constructor-style-printer from racket/struct exists,
;; this is it, and otherwise this is a cheap immitation.
(define make-constructor-style-printer
(with-handlers ([exn:fail:filesystem?
(λ (e)
(λ (get-head get-elems)
(λ (v out mode)
(define head (get-head v))
(define elems (get-elems v))
(fprintf out "(~a" head)
(for ([elem elems])
(fprintf out " ~v" elem))
(fprintf out ")"))))])
(dynamic-require 'racket/struct 'make-constructor-style-printer)))
(struct fake-values [list]
#:transparent
#:methods gen:custom-write
[(define write-proc
(make-constructor-style-printer
(lambda (self) 'values)
(lambda (self) (fake-values-list self))))])

@ -1,16 +0,0 @@
#lang racket/base
(require (submod "../main.rkt" safe))
(module+ test
(require rackunit))
(module+ test
(check-exn (regexp (string-append
"txexpr.*: contract violation\n"
" *expected: txexpr-tag\\?\n"
" *given: 4\n"
" *in: the 1st argument.*"
" *blaming: .*test/contract-tests.rkt"))
(λ () (txexpr 4)))
)

@ -1,115 +0,0 @@
#lang racket/base
(require rackunit "../stx.rkt" "check-values.rkt"
(for-syntax racket/base))
;; Works on fully wrapped, non-wrapped, and partially
;; wrapped values, and it checks that the the inputs
;; are wrapped in all the same places. It checks scopes,
;; but it does not check source location.
(define-binary-check (check-stx=? stx=? actual expected))
(define (stx=? a b)
(cond
[(and (identifier? a) (identifier? b))
(bound-identifier=? a b)]
[(and (syntax? a) (syntax? b))
(and (bound-identifier=? (datum->syntax a '||) (datum->syntax b '||))
(stx=? (syntax-e a) (syntax-e b)))]
[else
(equal?/recur a b stx=?)]))
(define-syntax check-values-stx=?
(lambda (stx)
(syntax-case stx []
[(_ actual-expr expected-expr)
(syntax/loc stx
(check/values check-stx=? actual-expr expected-expr))])))
;; ---------------------------------------------------------
;; Predicates
(check-pred stx-xexpr? "A leaf on a string")
(check-pred stx-xexpr? #'"A leaf in syntax")
(check-pred stx-xexpr? #'(div))
(check-pred stx-xexpr? #'(div ((id "top")) "Hello" (p "World")))
(check-pred stx-xexpr? `(div ((id ,#'"top")) "Hello" ,#'(p "World")))
(check-false (stx-txexpr? "A leaf without a tag"))
(check-pred stx-txexpr? '(div))
(check-pred stx-txexpr? #'(div))
(check-pred stx-txexpr? #'(div ((id "top")) "Hello" (p "World")))
(check-pred stx-txexpr? `(div ((id ,#'"top")) "Hello" ,#'(p "World")))
(check-pred stx-txexpr-tag? 'div)
(check-pred stx-txexpr-tag? #'div)
(check-pred stx-txexpr-tag? 'this-is-something-else)
(check-pred stx-txexpr-tag? #'this-is-something-else)
(check-pred stx-txexpr-attrs? '())
(check-pred stx-txexpr-attrs? #'())
(check-pred stx-txexpr-attrs? '((id "top") (style "color: blue")))
(check-pred stx-txexpr-attrs? #'((id "top") (style "color: blue")))
(check-pred stx-txexpr-attrs? `((id "top") (style ,#'"color: blue")))
;; ---------------------------------------------------------
;; Accessors
(check-values-stx=? (stx-txexpr->values '(p))
(values 'p null null))
(check-values-stx=? (stx-txexpr->values '(p "foo"))
(values 'p null '("foo")))
(check-values-stx=? (stx-txexpr->values '(p ((key "value"))))
(values 'p '((key "value")) null))
(check-values-stx=? (stx-txexpr->values '(p ((key "value")) "foo"))
(values 'p '((key "value")) '("foo")))
(check-values-stx=? (stx-txexpr->values #'(p))
(values #'p null null))
(check-values-stx=? (stx-txexpr->values #'(p "foo"))
(values #'p null (list #'"foo")))
(check-values-stx=? (stx-txexpr->values #'(p ((key "value"))))
(values #'p #'((key "value")) null))
(check-values-stx=? (stx-txexpr->values #'(p ((key "value")) "foo"))
(values #'p #'((key "value")) (list #'"foo")))
(check-values-stx=? (stx-txexpr->values `(,#'p))
(values #'p null null))
(check-values-stx=? (stx-txexpr->values `(p ,#'"foo"))
(values 'p null (list #'"foo")))
(check-values-stx=? (stx-txexpr->values `(p ((,#'key "value")) . ,#'("foo")))
(values 'p `((,#'key "value")) (list #'"foo")))
(check-stx=? (stx-txexpr-tag '(p ((key "value"))"foo" (em "square")))
'p)
(check-stx=? (stx-txexpr-tag #'(p ((key "value"))"foo" (em "square")))
#'p)
(check-stx=? (stx-txexpr-attrs '(p ((key "value"))"foo" "bar" (em "square")))
'((key "value")))
(check-stx=? (stx-txexpr-attrs #'(p ((key "value"))"foo" "bar" (em "square")))
#'((key "value")))
(check-stx=? (stx-txexpr-attrs '(p "foo" "bar" (em "square")))
'())
(check-stx=? (stx-txexpr-attrs #'(p "foo" "bar" (em "square")))
'())
(check-stx=? (stx-txexpr-elements '(p "foo" "bar" (em "square")))
'("foo" "bar" (em "square")))
(check-stx=? (stx-txexpr-elements #'(p "foo" "bar" (em "square")))
(list #'"foo" #'"bar" #'(em "square")))
(check-stx=? (stx-txexpr-elements '(p ((k "v"))"foo" "bar" (em "square")))
'("foo" "bar" (em "square")))
(check-stx=? (stx-txexpr-elements #'(p ((k "v"))"foo" "bar" (em "square")))
(list #'"foo" #'"bar" #'(em "square")))
(check-stx=? (stx-txexpr-elements #'(p ((k "v"))"foo" . ("bar" (em "square"))))
(list #'"foo" #'"bar" #'(em "square")))
(check-stx=? (stx-txexpr-elements `(p ((k "v"))"foo" .,#'("bar" (em "square"))))
(list "foo" #'"bar" #'(em "square")))
;; ---------------------------------------------------------

@ -1,326 +0,0 @@
#lang racket/base
(require (for-syntax racket/base racket/syntax syntax/strip-context))
;; use a separate test file to avoid cycle in loading
(define-syntax (test-safe-and-unsafe stx)
(syntax-case stx ()
[(_ . exprs)
(with-syntax ([module-without-contracts (generate-temporary)]
[module-with-contracts (generate-temporary)])
(replace-context stx
#'(begin
(module module-without-contracts racket
(require rackunit "../main.rkt" "check-values.rkt")
. exprs)
(require 'module-without-contracts)
(module module-with-contracts racket
(require rackunit (submod "../main.rkt" safe) "check-values.rkt")
. exprs)
(require 'module-with-contracts))))]))
(test-safe-and-unsafe
(check-true (txexpr-tag? 'foo))
(check-false (txexpr-tag? "foo"))
(check-false (txexpr-tag? 3))
(check-false (txexpr-tags? 'foo))
(check-true (txexpr-tags? '(foo bar)))
(check-true (txexpr-attr? '(key "value")))
(check-false (txexpr-attr? '(key "value" "another")))
(check-false (txexpr-attr? '(key 0 "value")))
(check-true (txexpr-attrs? '()))
(check-true (txexpr-attrs? '((key "value"))))
(check-true (txexpr-attrs? '((key "value") (foo "bar"))))
(check-false (txexpr-attrs? '((key "value") "foo" "bar"))) ; content, not attr
(check-false (txexpr-attrs? '(key "value"))) ; not a nested list
(check-false (txexpr-attrs? '(("key" "value")))) ; two strings
(check-false (txexpr-attrs? '((key value)))) ; two symbols
(check-true (txexpr-element? "string"))
(check-true (txexpr-element? 'amp))
(check-true (txexpr-element? '(p "string")))
(check-true (txexpr-element? 2)) ; a valid-char, but not in v6.0 xml:xexpr?
(check-true (txexpr-element? 65)) ; a valid-char
(check-false (txexpr-element? 0)) ; not a valid-char
(check-true (txexpr-elements? '("p" "foo" "123")))
(check-true (txexpr-elements? '("p" "foo" 123))) ; includes number
(check-true (txexpr-elements? '(p "foo" "123"))) ; includes symbol
(check-false (txexpr-elements? "foo")) ; not a list
(check-false (txexpr-elements? '(((key "value")) "foo" "bar"))) ; includes attr
(check-false (txexpr-elements? '("foo" "bar" ((key "value"))))) ; malformed
(check-true (txexpr? '(p)))
(check-true (txexpr? '(div 2)))
(check-true (txexpr? '(div (div ((foo "bar")) 2))))
(check-true (txexpr? '(p "foo" "bar")))
(check-true (txexpr? '(p ((key "value")) "foo" "bar")))
(check-true (txexpr? '(p 123))) ; content is a number
(check-false (txexpr? "foo")) ; not a list with symbol
(check-false (txexpr? '(p "foo" "bar" ((key "value"))))) ; malformed
(check-false (txexpr? '("p" "foo" "bar"))) ; no name
(check-not-exn (λ _ (validate-txexpr '(p))))
(check-not-exn (λ _ (validate-txexpr '(p "foo" "bar"))))
(check-not-exn (λ _ (validate-txexpr '(p ((key "value")) "foo" "bar"))))
(check-not-exn (λ _ (validate-txexpr '(p () "foo" "bar"))))
(check-not-exn (λ _ (validate-txexpr '(p 123)))) ; content is a valid-char
(check-exn exn:fail? (λ _ (validate-txexpr "foo"))) ; not a list with symbol
(check-exn exn:fail? (λ _ (validate-txexpr '(p "foo" "bar" ((key "value")))))) ; malformed
(check-exn exn:fail? (λ _ (validate-txexpr '("p" "foo" "bar")))) ; no name
(check-exn exn:fail? (λ _ (validate-txexpr '(root ((id "top")(class 42)))))) ; malformed attrs
(check-exn exn:fail? (λ _ (validate-txexpr `(root ,(void))))) ; invalid element type
(define-syntax (check-validate-exn-msg stx)
(syntax-case stx ()
[(_ tx) (syntax/loc stx (check-validate-exn-msg tx ""))]
[(_ tx msg)
(syntax/loc stx
(check-equal? (with-handlers ([exn:fail:contract? (λ (e) (exn-message e))])
(validate-txexpr tx)) msg))]))
;; Root element not a list
(check-validate-exn-msg
"foo"
"validate-txexpr: contract violation\n expected: tagged X-expression\n given: \"foo\"")
;; No name
(check-validate-exn-msg
'("p" "foo" "bar")
"validate-txexpr: tag must be a symbol\n tag: \"p\"\n in: '(\"p\" \"foo\" \"bar\")")
;; Invalid element
(check-validate-exn-msg
'(p "foo" "bar" ((key "value")))
"validate-txexpr: element not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)\n element: '((key \"value\"))\n in: '(p \"foo\" \"bar\" ((key \"value\")))")
;; Malformed attribute list
(check-validate-exn-msg
'(p ((key "val") "foo" "bar") "hi")
"validate-txexpr: attribute is not a list of the form '(symbol \"string\")\n attribute: \"foo\"\n in: '(p ((key \"val\") \"foo\" \"bar\") \"hi\")")
;; Invalid attribute key
(check-validate-exn-msg
'(root ((id "top") (class 42)))
"validate-txexpr: attribute value is not a string\n attribute value: 42\n in: '(root ((id \"top\") (class 42)))")
;; Invalid attribute value
(check-validate-exn-msg
'(root ((id "top") ("class" 42)))
"validate-txexpr: attribute key is not a symbol\n attribute key: \"class\"\n in: '(root ((id \"top\") (\"class\" 42)))")
;; Invalid element type
(check-validate-exn-msg
`(root ,(void))
"validate-txexpr: element not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)\n element: #<void>\n in: '(root #<void>)")
;; (Deeply nested) No name: error should pinpoint element in 'div txexpr
(check-validate-exn-msg
'(fine-outer [[type "valid"]] (div (br) ("p" "foo" "bar")))
"validate-txexpr: element not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)\n element: '(\"p\" \"foo\" \"bar\")\n in: '(div (br) (\"p\" \"foo\" \"bar\"))")
;; (Deeply nested) Invalid element: error should pinpoint element in 'p txexpr
(check-validate-exn-msg
'(fine-outer [[type "valid"]] (div (br) (p "foo" "bar" ((key "value")))))
"validate-txexpr: element not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)\n element: '((key \"value\"))\n in: '(p \"foo\" \"bar\" ((key \"value\")))")
;; (Deeply nested) Malformed attribute list: error should pinpoint attr in 'p txexpr
(check-validate-exn-msg
'(fine-outer [[type "valid"]] (div (br) (p ((key "val") "foo" "bar") "hi")))
"validate-txexpr: attribute is not a list of the form '(symbol \"string\")\n attribute: \"foo\"\n in: '(p ((key \"val\") \"foo\" \"bar\") \"hi\")")
;; (Deeply nested) Invalid attribute key: error should pinpoint attr key in 'p txexpr
(check-validate-exn-msg
'(fine-outer [[type "valid"]] (div (br) (p ((id "top") (class 42)))))
"validate-txexpr: attribute value is not a string\n attribute value: 42\n in: '(p ((id \"top\") (class 42)))")
;; (Deeply nested) Invalid attribute value: error should pinpoint attr val in 'p txexpr
(check-validate-exn-msg
'(fine-outer [[type "valid"]] (div (br) (p ((id "top") ("class" 42)))))
"validate-txexpr: attribute key is not a symbol\n attribute key: \"class\"\n in: '(p ((id \"top\") (\"class\" 42)))")
;; (Deeply nested) Invalid element type: error should pinpoint element in 'p txexpr
(check-validate-exn-msg
`(fine-outer [[type "valid"]] (div (br) (p ,(void))))
"validate-txexpr: element not a valid element (= txexpr, string, symbol, XML char, cdata, or comment)\n element: #<void>\n in: '(p #<void>)")
(check-txexprs-equal? (make-txexpr 'p) '(p))
(check-txexprs-equal? (make-txexpr 'p '((key "value"))) '(p ((key "value"))))
(check-txexprs-equal? (make-txexpr 'p null '("foo" "bar")) '(p "foo" "bar"))
(check-txexprs-equal? (make-txexpr 'p '((key "value")) (list "foo" "bar"))
'(p ((key "value")) "foo" "bar"))
(check-txexprs-equal? (txexpr 'p) '(p))
(check-txexprs-equal? (txexpr 'p '((key "value"))) '(p ((key "value"))))
(check-txexprs-equal? (txexpr 'p null '("foo" "bar")) '(p "foo" "bar"))
(check-txexprs-equal? (txexpr 'p '((key "value")) (list "foo" "bar"))
'(p ((key "value")) "foo" "bar"))
(check-txexprs-equal? (txexpr* 'p) '(p))
(check-txexprs-equal? (txexpr* 'p '((key "value"))) '(p ((key "value"))))
(check-txexprs-equal? (txexpr* 'p null "foo" "bar") '(p "foo" "bar"))
(check-txexprs-equal? (txexpr* 'p '((key "value")) "foo" "bar")
'(p ((key "value")) "foo" "bar"))
(check-values=? (txexpr->values '(p))
(values 'p null null))
(check-values=? (txexpr->values '(p "foo"))
(values 'p null '("foo")))
(check-values=? (txexpr->values '(p ((key "value"))))
(values 'p '((key "value")) null))
(check-values=? (txexpr->values '(p ((key "value")) "foo"))
(values 'p '((key "value")) '("foo")))
(check-equal? (values->list (txexpr->values '(p)))
(txexpr->list '(p)))
(check-equal? (values->list (txexpr->values '(p "foo")))
(txexpr->list '(p "foo")))
(check-equal? (values->list (txexpr->values '(p ((key "value")))))
(txexpr->list '(p ((key "value")))))
(check-equal? (values->list (txexpr->values '(p ((key "value")) "foo")))
(txexpr->list '(p ((key "value")) "foo")))
;; testing the match expander success
(check-match '(p ((key "value")) "leaf")
(txexpr 'p `((key ,val)) (list "leaf"))
(string=? val "value"))
;; testing the match expander failure
(check-false (match '(p ((key "value")) "something")
[(txexpr 'p _ (list "else")) #true]
[_ #false]))
(check-false (match "foo"
[(txexpr _ _ _) #true]
[_ #false]))
(check-equal? (get-tag '(p ((key "value"))"foo" "bar" (em "square"))) 'p)
(check-equal? (get-attrs '(p ((key "value"))"foo" "bar" (em "square"))) '((key "value")))
(check-equal? (get-elements '(p ((key "value"))"foo" "bar" (em "square")))
'("foo" "bar" (em "square")))
(check-equal? (->txexpr-attr-key "foo") 'foo)
(check-equal? (->txexpr-attr-key 'foo) 'foo)
(check-equal? (->txexpr-attr-key (string->path "foo")) 'foo)
(check-equal? (->txexpr-attr-value "foo") "foo")
(check-equal? (->txexpr-attr-value 'foo) "foo")
(check-equal? (->txexpr-attr-value (string->path "foo")) "foo")
(check-equal? (attrs->hash '((foo "bar"))) '#hasheq((foo . "bar")))
(check-equal? (attrs->hash '((foo "bar") (foo "fraw"))) '#hasheq((foo . "bar")))
(check-equal? (attrs->hash #:hash-style? #t '((foo "bar") (foo "fraw"))) '#hasheq((foo . "fraw")))
(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw")) '#hasheq((foo . "bar")))
(check-equal? (attrs->hash '((foo "bar")) '(foo "fraw") 'foo "dog") '#hasheq((foo . "bar")))
(check-exn exn:fail:contract? (λ _ (attrs->hash 'foo "bar" 'zam)))
(check-equal? (sort (hash->attrs '#hash((foo . "bar")(hee . "haw"))) string<? #:key cadr)
(sort '((foo "bar")(hee "haw")) string<? #:key second))
(check-equal? (attr-ref '(p ((foo "bar"))) 'foo) "bar")
(check-exn exn:fail? (λ _ (attr-ref '(p ((foo "bar"))) 'zam)))
(check-equal? (attr-ref '(p ((foo "bar"))) 'zam 42) 42)
(check-equal? (attr-ref '(p ((foo "bar"))) 'zam (λ _ (* 6 7))) 42)
(check-equal? (attr-ref '((foo "bar")) 'foo) "bar")
(check-exn exn:fail? (λ _ (attr-ref '((foo "bar")) 'zam)))
(check-equal? (attr-ref '((foo "bar")) 'zam 42) 42)
(check-equal? (attr-ref '((foo "bar")) 'zam (λ _ (* 6 7))) 42)
(check-txexprs-equal? (attr-set '(p ((foo "bar"))) 'foo "fraw") '(p ((foo "fraw"))))
(check-txexprs-equal? (attr-set* '(p ((foo "bar"))) 'foo "fraw") '(p ((foo "fraw"))))
(check-true (let ([result (attr-set* '(p ((foo "bar"))) 'foo "fraw" 'zim 'zam)])
(and (member '(foo "fraw") (get-attrs result))
(member '(zim "zam") (get-attrs result)) #t)))
(check-txexprs-equal? (attr-join '(p ((foo "bar"))) 'foo "zam") '(p ((foo "bar zam"))))
(check-txexprs-equal? (attr-join '(tx ((foo "bar")) baz (p bin)) 'key 'val)
'(tx ((foo "bar") (key "val")) baz (p bin)))
(check-true (let ([result (attr-join '(p ((foo "bar"))) 'zim "zam")])
(and (member '(foo "bar") (get-attrs result))
(member '(zim "zam") (get-attrs result)) #t)))
(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) 'color))
(check-true (attrs-have-key? '(p ((color "red")(shape "circle"))) "color"))
(check-false (attrs-have-key? '((color "red")(shape "circle")) 'nonexistent))
(check-true (attrs-equal? '(p ((color "red")(shape "circle")))
'(foo ((color "red")(shape "circle")))))
(check-false (attrs-equal? '(p ((color "red")(shape "circle")))
'(foo ((color "blue")(shape "circle")))))
(check-true (attrs-equal? '(p ((color "red")(shape "circle")))
'(foo ((shape "circle")(color "red")))))
(check-false (attrs-equal? '(p ((color "red")(shape "circle")))
'(foo ((color "red")))))
(check-true (attrs-equal? '((color "red")(shape "circle"))
'((color "red")(shape "circle"))))
(check-false (attrs-equal? '((color "red")(shape "circle"))
'((color "blue")(shape "circle"))))
(check-true (attrs-equal? '((color "red")(shape "circle"))
'((shape "circle")(color "red"))))
(check-false (attrs-equal? '((color "red")(shape "circle"))
'((color "red"))))
(check-true (attrs-equal? '((foo "bar")(foo "zam")(zing "zong"))
'((foo "zam")(zing "zong")(foo "bar"))))
(check-false (attrs-equal? '((foo "bar")(foo "zam")(zing "zong"))
'((foo "different")(zing "zong")(foo "bar"))))
(define-simple-check (check-attrs-equal? attrs1 attrs2) (attrs-equal? attrs1 attrs2))
(check-attrs-equal? '((foo "bar")(foo "zam")) '((foo "zam")(foo "bar")))
(check-txexprs-equal? (remove-attrs '(p ((foo "bar")) "hi")) '(p "hi"))
(check-txexprs-equal? (remove-attrs '(p ((foo "bar")) "hi" (p ((foo "bar")) "hi"))) '(p "hi" (p "hi")))
(check-txexprs-equal? (map-elements (λ (x) (if (string? x) "boing" x))
'(p ((id "zam")) "foo" "bar" (em "square")))
'(p ((id "zam")) "boing" "boing" (em "boing")))
(check-equal? (attr-set '(p) 'foo "zim") '(p ((foo "zim"))))
(check-equal? (attr-set '(p ((foo "bar")(foo "zam"))) 'foo "zim") '(p ((foo "zim"))))
(check-exn exn:fail:contract? (λ _ (attr-set* '(p) 'foo "bar" 'zam)))
(define split-this-tx '(root (meta "foo" "bar") "hello" "world" (meta "foo2" "bar2")
(em "goodnight" "moon" (meta "foo3" "bar3"))))
(define split-predicate (λ (x) (and (txexpr? x) (eq? 'meta (get-tag x)))))
(check-txexprs-equal? (call-with-values (λ () (splitf-txexpr split-this-tx split-predicate)) list)
(list '(root "hello" "world" (em "goodnight" "moon")) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3"))))
(define split-proc (λ (x) '(div "foo")))
(check-txexprs-equal? (call-with-values (λ () (splitf-txexpr split-this-tx split-predicate split-proc)) list)
(list '(root (div "foo") "hello" "world" (div "foo") (em "goodnight" "moon" (div "foo"))) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3"))))
(define false-pred (λ (x) (and (txexpr? x) (eq? 'nonexistent-tag (get-tag x)))))
(check-equal? (findf*-txexpr split-this-tx split-predicate) '((meta "foo" "bar") (meta "foo2" "bar2") (meta "foo3" "bar3")))
(check-false (findf*-txexpr split-this-tx false-pred))
(check-equal? (findf-txexpr split-this-tx split-predicate) '(meta "foo" "bar"))
(check-false (findf-txexpr split-this-tx false-pred))
(check-equal? (xexpr->html '(root (script "3 > 2") "Why is 3 > 2?"))
"<root><script>3 > 2</script>Why is 3 &gt; 2?</root>")
(check-equal? (xexpr->html '(root (div "<![CDATA[3 > 2]]>") "Why is 3 > 2?"))
"<root><div><![CDATA[3 > 2]]></div>Why is 3 &gt; 2?</root>")
;; comment
(check-equal? (xexpr->html '(root "<!-- comment -->" "Why is 3 > 2?"))
"<root><!-- comment -->Why is 3 &gt; 2?</root>")
;; malformed comment: merged with next string
(check-equal? (xexpr->html '(root "<!-- comment -->Why is 3 > 2?"))
"<root>&lt;!-- comment --&gt;Why is 3 &gt; 2?</root>")
;; malformed comment: missing double hyphen at end
(check-equal? (xexpr->html '(root "<!-- comment ->" "Why is 3 > 2?"))
"<root>&lt;!-- comment -&gt;Why is 3 &gt; 2?</root>"))

@ -1,39 +0,0 @@
#lang racket/base
(require "../main.rkt" sugar/define)
(module+ test
(require rackunit "../main.rkt"))
(define+provide+safe (attr-ref* tx key)
(txexpr? can-be-txexpr-attr-key? . -> . txexpr-attr-values?)
(define results empty)
(let loop ([tx tx])
(when (and (txexpr? tx) (attrs-have-key? tx key) (attr-ref tx key))
(set! results (cons (attr-ref tx key) results))
(map loop (get-elements tx))
(void)))
(reverse results))
(module+ test
(check-txexprs-equal? (attr-ref* '(root ((foo "bar")) "hello" "world" (meta ((foo "zam")) "bar2")
(em ((foo "zam")) "goodnight" "moon")) 'foo) '("bar" "zam" "zam"))
(check-txexprs-equal? (attr-ref* '(root ((foo "bar")) "hello" "world" (meta ((foo "zam")) "bar2")
(em ((foo "zam")) "goodnight" "moon")) 'nonexistent-key) '()))
;; convert list of alternating keys & values to attr
;; with override behavior (using hash)
(define+provide+safe (merge-attrs . items)
(() #:rest list-of-can-be-txexpr-attrs? . ->* . txexpr-attrs?)
(hash->attrs (apply (λ xs (attrs->hash #:hash-style? #t xs)) items)))
(module+ test
(check-true (attrs-equal? (merge-attrs 'foo "bar") '((foo "bar"))))
(check-true (attrs-equal? (merge-attrs '(foo "bar")) '((foo "bar"))))
(check-true (attrs-equal? (merge-attrs '((foo "bar"))) '((foo "bar"))))
(check-true (attrs-equal? (merge-attrs "foo" 'bar) '((foo "bar"))))
(check-true (attrs-equal? (merge-attrs "foo" "bar" "goo" "gar") '((foo "bar")(goo "gar"))))
(check-true (attrs-equal? (merge-attrs (merge-attrs "foo" "bar" "goo" "gar") "hee" "haw")
'((foo "bar")(goo "gar")(hee "haw"))))
(check-true (attrs-equal? (merge-attrs '((foo "bar")(goo "gar")) "foo" "haw") '((foo "haw")(goo "gar")))))
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