mbutterick
/
beautiful-racket
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

capitalize nonliterals

Browse Source
dev-elider-3
Matthew Butterick 8 years ago
parent 7164c4afec
commit d768d518bb
2 changed files with 57 additions and 46 deletions
Show Stats Download Patch File Download Diff File

83
beautiful-racket-lib/br/define.rkt
Unescape Escape View File

@ -1,9 +1,19 @@
#lang racket/base
(require (for-syntax racket/base syntax/parse racket/syntax syntax/datum syntax/strip-context) sugar/define)
(require (for-syntax racket/list racket/base syntax/parse racket/syntax syntax/datum syntax/strip-context) sugar/define)
(provide (all-defined-out))
;; everything is prefixed br: whether it needs it or not so it can be stripped by #lang br
(define-for-syntax (generate-literals pats)
;; generate literals for any symbols that are not ... or _ or UPPERCASE
(for*/list ([pat-arg (in-list (flatten (map (λ(stx) (or (syntax->list stx) stx)) (syntax->list pats))))]
[pat-datum (in-value (syntax->datum pat-arg))]
#:when (and (symbol? pat-datum)
(not (eq? pat-datum '...)) (not (eq? pat-datum '_))
(not (let ([str (symbol->string pat-datum)])
(equal? (string-upcase str) str)))))
pat-arg))
;; todo: support `else` case
(define-syntax (br:define-cases stx)
(define-syntax-class syntaxed-id
@ -29,14 +39,15 @@
;; syntax matcher
[(_ top-id:syntaxed-id [(syntax pat) body ...] ...+)
#'(define-syntax top-id.name (λ (stx)
(define result
(syntax-case stx ()
[pat body ...] ...
[else (raise-syntax-error 'define-cases (format "no matching case for syntax pattern `~a`" (syntax->datum stx)) (syntax->datum #'top-id.name))]))
(if (not (syntax? result))
(datum->syntax stx result)
result)))]
(with-syntax ([(LITERAL ...) (generate-literals #'(pat ...))])
#'(define-syntax top-id.name (λ (stx)
(define result
(syntax-case stx (LITERAL ...)
[pat body ...] ...
[else (raise-syntax-error 'define-cases (format "no matching case for syntax pattern `~a`" (syntax->datum stx)) (syntax->datum #'top-id.name))]))
(if (not (syntax? result))
(datum->syntax stx result)
result))))]
;; function matcher
[(_ top-id:id [(_ pat-arg ... . rest-arg) body ...] ...)
@ -51,7 +62,7 @@
(define (foo-func) 'got-foo-func)
(br:define-cases #'op
[#'(_ "+") #''got-plus]
[#'(_ arg) #''got-something-else]
[#'(_ ARG) #''got-something-else]
[#'(_) #'(foo-func)]
[#'_ #'foo-val])
@ -93,16 +104,16 @@
;; syntax
[(_ (syntax (id pat-arg ... . rest-arg)) body ...) ; (define #'(foo arg) #'(+ arg arg))
#'(br:define-cases (syntax id) [(syntax (_ pat-arg ... . rest-arg)) body ...])]
#'(br:define-cases (syntax id) [(syntax (_ pat-arg ... . rest-arg)) body ...])]
[(_ sid:syntaxed-id sid2:syntaxed-id) ; (define #'f1 #'f2)
#'(define-syntax sid.name (make-rename-transformer sid2))]
#'(define-syntax sid.name (make-rename-transformer sid2))]
[(_ (syntax id) (syntax thing)) ; (define #'f1 #'42)
#'(br:define-cases (syntax id) [#'_ (syntax thing)])]
#'(br:define-cases (syntax id) [#'_ (syntax thing)])]
[(_ (sid:syntaxed-id stx-arg ...) expr ...) ; (define (#'f1 stx) expr ...)
(raise-syntax-error 'define "definition of a syntax transformer must use lambda notation, because otherwise it's too easy to confuse the compile-time shape and the run-time shape" (syntax->datum #'sid.name))]
(raise-syntax-error 'define "definition of a syntax transformer must use lambda notation, because otherwise it's too easy to confuse the compile-time shape and the run-time shape" (syntax->datum #'sid.name))]
[(_ sid:syntaxed-id (λ (stx-arg ...) expr ...)) ; (define #'f1 (λ(stx) expr ...)
#:fail-when (not (= (length (syntax->datum #'(stx-arg ...))) 1))
@ -118,16 +129,16 @@
(br:define #'plusser #'plus)
(check-equal? (plusser 42) +)
(check-equal? plusser +)
(br:define #'(times arg) #'(* arg arg))
(br:define #'(times ARG) #'(* ARG ARG))
(check-equal? (times 10) 100)
(br:define #'timeser #'times)
(check-equal? (timeser 12) 144)
(br:define #'fortytwo #'42)
(check-equal? fortytwo 42)
(check-equal? (let ()
(br:define #'(foo x)
(br:define #'(foo X)
(with-syntax ([zam +])
#'(zam x x))) (foo 42)) 84)
#'(zam X X))) (foo 42)) 84)
;; todo: error from define not trapped by check-exn
#;(check-exn exn:fail:syntax? (λ _ (br:define (#'times stx stx2) #'*)))
(begin
@ -137,28 +148,28 @@
(define-syntax-rule (br:debug-define (syntax (id pat-arg ... . rest-arg)) body-exp)
(br:define #'(id pat-arg ... . rest-arg)
#`(begin
(for-each displayln
(list
(format "input pattern = #'~a" '#,'(id pat-arg ... . rest-arg))
(format "output pattern = #'~a" (cadr '#,'body-exp))
(format "invoked as = ~a" (syntax->datum #'(id pat-arg ... . rest-arg)))
(format "expanded as = ~a" '#,(syntax->datum body-exp))
(format "evaluated as = ~a" #,body-exp)))
#,body-exp)))
(br:define #'(id pat-arg ... . rest-arg)
#`(begin
(for-each displayln
(list
(format "input pattern = #'~a" '#,'(id pat-arg ... . rest-arg))
(format "output pattern = #'~a" (cadr '#,'body-exp))
(format "invoked as = ~a" (syntax->datum #'(id pat-arg ... . rest-arg)))
(format "expanded as = ~a" '#,(syntax->datum body-exp))
(format "evaluated as = ~a" #,body-exp)))
#,body-exp)))
(module+ test
(require rackunit racket/port)
(parameterize ([current-output-port (open-output-nowhere)])
(check-equal? (let ()
(br:debug-define #'(foo X Y Z)
#'(apply + (list X Y Z)))
(foo 1 2 3)) 6)
(check-equal? (let ()
(br:debug-define #'(foo X ...) #'(apply * (list X ...)))
(foo 10 11 12)) 1320)))
(require rackunit racket/port)
(parameterize ([current-output-port (open-output-nowhere)])
(check-equal? (let ()
(br:debug-define #'(foo X Y Z)
#'(apply + (list X Y Z)))
(foo 1 2 3)) 6)
(check-equal? (let ()
(br:debug-define #'(foo X ...) #'(apply * (list X ...)))
(foo 10 11 12)) 1320)))

20
beautiful-racket/br/demo/basic/expander.rkt
Unescape Escape View File

@ -104,26 +104,26 @@
(define (basic:or . args) (cond->int (ormap true? args)))
(define-cases #'expr
[#'(_ COMP-EXPR "AND" EXPR) #'(basic:and COMP-EXPR EXPR)]
[#'(_ COMP-EXPR "OR" EXPR) #'(basic:or COMP-EXPR EXPR)]
[#'(_ COMP-EXPR "AND" SUBEXPR) #'(basic:and COMP-EXPR SUBEXPR)]
[#'(_ COMP-EXPR "OR" SUBEXPR) #'(basic:or COMP-EXPR SUBEXPR)]
[#'(_ COMP-EXPR) #'COMP-EXPR])
(define-cases #'comp-expr
[#'(_ LEXPR "=" REXPR) #'(comp-expr LEXPR "equal?" REXPR)] ; special case because = is overloaded
[#'(_ LEXPR op REXPR) (inject-syntax ([#'OP (string->symbol (syntax->datum #'op))])
#'(cond->int (OP LEXPR REXPR)))]
[#'(_ expr) #'expr])
[#'(_ ARG) #'ARG])
(define <> (compose1 not equal?))
(define-cases #'sum
[#'(_ term "+" sum) #'(+ term sum)]
[#'(_ term "-" sum) #'(- term sum)]
[#'(_ term) #'term])
[#'(_ TERM "+" SUM) #'(+ TERM SUM)]
[#'(_ TERM "-" SUM) #'(- TERM SUM)]
[#'(_ TERM) #'TERM])
(define-cases #'product
[#'(_ factor "*" product) #'(* factor product)]
[#'(_ factor "/" product) #'(/ factor product)]
[#'(_ factor) #'factor])
[#'(_ FACTOR "*" PRODUCT) #'(* FACTOR PRODUCT)]
[#'(_ FACTOR "/" PRODUCT) #'(/ FACTOR PRODUCT)]
[#'(_ FACTOR) #'FACTOR])
(define print-list list)
@ -136,7 +136,7 @@
[(list print-list-item ...) (for-each displayln print-list-item)]))
(define (TAB num) (make-string num #\space))
(define #'(INT EXPR ...) #'(inexact->exact (truncate (expr EXPR ...))))
(define #'(INT ARG ...) #'(inexact->exact (truncate (expr ARG ...))))
(define (SIN num) (sin num))
(define (ABS num) (inexact->exact (abs num)))
(define (RND num) (* (random) num))

Write Preview
Loading…
Cancel
Save