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import: hackage: Add recognition of 'true' and 'false' symbols.

* guix/import/cabal.scm (is-true, is-false, lex-true, lex-false): New procedures.
  (lex-word): Use them.
  (make-cabal-parser): Add TRUE and FALSE tokens.
  (eval): Add entries for 'true and 'false symbols.
This commit is contained in:
Federico Beffa 2015-11-11 10:39:38 +01:00
parent b72a44100e
commit 7716f55c83

View file

@ -138,7 +138,7 @@ to the stack."
"Generate a parser for Cabal files."
(lalr-parser
;; --- token definitions
(CCURLY VCCURLY OPAREN CPAREN TEST ID VERSION RELATION
(CCURLY VCCURLY OPAREN CPAREN TEST ID VERSION RELATION TRUE FALSE
(right: IF FLAG EXEC TEST-SUITE SOURCE-REPO BENCHMARK LIB OCURLY)
(left: OR)
(left: PROPERTY AND)
@ -206,6 +206,8 @@ to the stack."
(if-then (IF tests OCURLY exprs CCURLY) : `(if ,$2 ,$4 ())
(IF tests open exprs close) : `(if ,$2 ,$4 ()))
(tests (TEST OPAREN ID CPAREN) : `(,$1 ,$3)
(TRUE) : 'true
(FALSE) : 'false
(TEST OPAREN ID RELATION VERSION CPAREN)
: `(,$1 ,(string-append $3 " " $4 " " $5))
(TEST OPAREN ID RELATION VERSION AND RELATION VERSION CPAREN)
@ -350,6 +352,10 @@ matching a string against the created regexp."
(define (is-if s) (string-ci=? s "if"))
(define (is-true s) (string-ci=? s "true"))
(define (is-false s) (string-ci=? s "false"))
(define (is-and s) (string=? s "&&"))
(define (is-or s) (string=? s "||"))
@ -424,6 +430,10 @@ string with the read characters."
(define (lex-if loc) (make-lexical-token 'IF loc #f))
(define (lex-true loc) (make-lexical-token 'TRUE loc #t))
(define (lex-false loc) (make-lexical-token 'FALSE loc #f))
(define (lex-and loc) (make-lexical-token 'AND loc #f))
(define (lex-or loc) (make-lexical-token 'OR loc #f))
@ -489,6 +499,8 @@ LOC is the current port location."
(let* ((w (read-delimited " ()\t\n" port 'peek)))
(cond ((is-if w) (lex-if loc))
((is-test w port) (lex-test w loc))
((is-true w) (lex-true loc))
((is-false w) (lex-false loc))
((is-and w) (lex-and loc))
((is-or w) (lex-or loc))
((is-id w) (lex-id w loc))
@ -714,6 +726,8 @@ the ordering operation and the version."
(('os name) (os name))
(('arch name) (arch name))
(('impl name) (impl name))
('true #t)
('false #f)
(('not name) (not (eval name)))
;; 'and' and 'or' aren't functions, thus we can't use apply
(('and args ...) (fold (lambda (e s) (and e s)) #t (eval args)))