You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pollen/main.rkt

117 lines
5.3 KiB
Racket

#lang racket/base
(require racket/list)
11 years ago
(require (planet mb/pollen/tools) (planet mb/pollen/main-helper))
(require (only-in (planet mb/pollen/ptree-decode) ptree-source-decode))
(require (only-in (planet mb/pollen/predicates) ptree?))
11 years ago
(require (only-in (planet mb/pollen/file-tools) has-ext?))
(require (only-in (planet mb/pollen/world) POLLEN_TREE_EXT))
(provide (except-out (all-from-out racket/base) #%module-begin)
(rename-out [module-begin #%module-begin]))
(define-syntax-rule (module-begin expr ...)
(#%module-begin
;; this is here only so that dynamic-rerequire of a pollen module
;; transitively reloads the extras also.
;; if this isn't here, then dynamic-rerequire can't see them
;; and thus they are not tracked for changes.
(require-extras)
;; We want our module language to support require & provide
;; which are only supported at the module level, so ...
;; create a submodule to contain the input
;; and export as needed
;; doclang2_raw is a clone of scribble/doclang2 with decode disabled
;; helpful because it collects & exports content via 'doc
(module pollen-inner (planet mb/pollen/lang/doclang2_raw)
;; use same requires as top of main.rkt
;; (can't import them from surrounding module due to submodule rules)
11 years ago
(require (planet mb/pollen/tools) (planet mb/pollen/main-helper))
(require-and-provide-extras) ; brings in the project require files
;; #%top binding catches ids that aren't defined
;; here, convert them to basic xexpr
;; #%top is a syntax transformer that returns a function
;; λ x captures all the args (vs. λ(x), which only catches one)
;; and id is not spliced because it's syntax, not a true variable
;; WARNING! This is convenient for writing pollen documents
;; (which is why it works this way)
;; but it makes debugging tricky, because an undefined (symbol item ...)
;; is just treated as a valid tagged-xexpr, not an undefined function.
(define-syntax-rule (#%top . id)
11 years ago
;; todo: can #%top emit a debug message when a function hits it?
11 years ago
(λ x `(id ,@x)))
11 years ago
expr ... ; body of module
;; set up a hook for identifier 'here'
;; (but under a different name to avoid macrofication)
(define inner-here here)
(provide (all-defined-out))
(provide (all-from-out ; pollen file should bring its requires
(planet mb/pollen/tools))))
11 years ago
(require 'pollen-inner) ; provides doc & #%top, among other things
;; prepare the elements, and append inner-here as meta.
(define all-elements (cons
;; append inner-here as meta
;; put it first so it can be overridden by custom meta later on
`(meta "here" ,inner-here)
(cond
;; doc is probably a list, but might be a single string
[(string? doc) (list doc)]
[(tagged-xexpr? doc) (list doc)] ; if it's a single nx, just leave it
[(list? doc) doc]))) ; if it's nx content, splice it in
;; split out the metas now (in raw form)
(define-values (metas-raw main-raw)
(split-tag-from-xexpr 'meta (make-tagged-xexpr 'irrelevant-tag empty all-elements)))
(define metas (make-meta-hash metas-raw))
11 years ago
;; Policy: here in the core lang, do as little to main as possible.
;; The point is just to set it up for further processing.
;; Unlike Scribble, which insists on decoding,
;; Pollen just passes through the minimally processed data.
;; one exception: if file extension marks it as ptree, send it to the ptree decoder instead.
;; this tests inner-here (which is always the file name)
;; rather than (get metas 'here) which might have been overridden.
;; Because if it's overridden to something other than *.ptree,
;; ptree processing will fail.
;; This defeats rule that ptree file suffix triggers ptree decoding.
(define here-is-ptree? (ptree-source? (->path inner-here)))
(define main (apply (if here-is-ptree?
;; ptree source files will go this way,
ptree-source-decode
;; ... but other files, including pollen, will go this way.
;; Root is treated as a function.
;; If it's not defined elsewhere,
;; it just hits #%top and becomes a tagged-xexpr.
root) (tagged-xexpr-elements main-raw)))
(provide main metas
11 years ago
(except-out (all-from-out 'pollen-inner) inner-here) ; everything from user
(rename-out (inner-here here))) ; change identifier back (now safe from macrofication)
11 years ago
(module+ main
(displayln ";-------------------------")
(displayln (string-append "; pollen decoded 'main" (if here-is-ptree? " (as ptree)" "")))
(displayln ";-------------------------")
11 years ago
main
11 years ago
(displayln "")
(if here-is-ptree?
(displayln (format "(ptree? main) ~a" (ptree? main)))
(displayln (format "(tagged-xexpr? main) ~a" (tagged-xexpr? main))))
(displayln "")
(displayln ";-------------------------")
(displayln "; pollen 'metas")
(displayln ";-------------------------")
metas
)))