From: Mike D. Lowis <mike@mdlowis.com>
Date: Fri, 20 Jul 2012 17:44:28 +0000 (-0400)
Subject: Refactored lexer rule for string by adding a string character recognition predicate
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=6c361edd571c3d8c36d407716585655c9bff561d;p=archive%2Fdlang-scm.git

Refactored lexer rule for string by adding a string character recognition predicate
---

diff --git a/source/lexer.scm b/source/lexer.scm
index c1426c9..c4d1fe8 100644
--- a/source/lexer.scm
+++ b/source/lexer.scm
@@ -114,13 +114,17 @@
 
 (define (dlang/string in)
   (define text (string (char-match in #\")))
-  (while (and (not (eof-object? (buf-lookahead! in 1)))
-              (not (char=? #\newline (buf-lookahead! in 1)))
-              (not (char=? #\" (buf-lookahead! in 1))))
+  (while (dlang/string-char? in)
     (set! text (string-append text (string (buf-consume! in)))))
   (set! text (string-append text (string (char-match in #\"))))
   (token 'string text))
 
+(define (dlang/string-char? in)
+  (define ch (buf-lookahead! in 1))
+  (and (not (eof-object? ch))
+       (not (char=? #\newline ch))
+       (not (char=? #\" ch))))
+
 (define (dlang/symbol in)
   (token 'symbol
     (string-append