Hello again!
> * I'm sure there are other points -- please test and reply :)
Indeed!
One thing I noticed while look at Andreas' `wak' project is that the
use of `#!r6rs' seems to be pretty common, which conflicts with
Guile's support for SCSH-style block comments. Find attached a
(somewhat inelegant) patch that adds support for the `#!r6rs' lexeme
in the default reader. (What do people think about this? Is there a
better way to do it?)
Regards,
Julian
From f1af40142b47232e726cbe9f7bdc35d5fbf45602 Mon Sep 17 00:00:00 2001
From: Julian Graham <julian.gra...@aya.yale.edu>
Date: Sun, 23 May 2010 11:24:59 -0400
Subject: [PATCH] Support for the #!r6rs lexeme.
* libguile/read.c (scm_read_shebang): New function;
(scm_read_sharp): Call scm_read_shebang on '!', which delegates to
scm_read_scsh_block_comment as necessary.
---
libguile/read.c | 39 +++++++++++++++++++++++++++++++++++++--
1 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/libguile/read.c b/libguile/read.c
index c54fbb6..d169167 100644
--- a/libguile/read.c
+++ b/libguile/read.c
@@ -189,6 +189,7 @@ static SCM *scm_read_hash_procedures;
static inline SCM scm_read_scsh_block_comment (scm_t_wchar, SCM);
static SCM scm_read_r6rs_block_comment (scm_t_wchar, SCM);
static SCM scm_read_commented_expression (scm_t_wchar, SCM);
+static SCM scm_read_shebang (scm_t_wchar, SCM);
static SCM scm_get_hash_procedure (int);
/* Read from PORT until a delimiter (e.g., a whitespace) is read. Put the
@@ -309,7 +310,7 @@ flush_ws (SCM port, const char *eoferr)
eoferr = "read_sharp";
goto goteof;
case '!':
- scm_read_scsh_block_comment (c, port);
+ scm_read_shebang (c, port);
break;
case ';':
scm_read_commented_expression (c, port);
@@ -1109,6 +1110,40 @@ scm_read_scsh_block_comment (scm_t_wchar chr, SCM port)
return SCM_UNSPECIFIED;
}
+static inline SCM
+scm_read_shebang (scm_t_wchar chr, SCM port)
+{
+ int c = 0;
+ if ((c = scm_get_byte_or_eof (port)) != 'r')
+ {
+ scm_ungetc (c, port);
+ return scm_read_scsh_block_comment (chr, port);
+ }
+ if ((c = scm_get_byte_or_eof (port)) != '6')
+ {
+ scm_ungetc (c, port);
+ scm_ungetc ('r', port);
+ return scm_read_scsh_block_comment (chr, port);
+ }
+ if ((c = scm_get_byte_or_eof (port)) != 'r')
+ {
+ scm_ungetc (c, port);
+ scm_ungetc ('6', port);
+ scm_ungetc ('r', port);
+ return scm_read_scsh_block_comment (chr, port);
+ }
+ if ((c = scm_get_byte_or_eof (port)) != 's')
+ {
+ scm_ungetc (c, port);
+ scm_ungetc ('r', port);
+ scm_ungetc ('6', port);
+ scm_ungetc ('r', port);
+ return scm_read_scsh_block_comment (chr, port);
+ }
+
+ return SCM_UNSPECIFIED;
+}
+
static SCM
scm_read_r6rs_block_comment (scm_t_wchar chr, SCM port)
{
@@ -1323,7 +1358,7 @@ scm_read_sharp (scm_t_wchar chr, SCM port)
case '{':
return (scm_read_extended_symbol (chr, port));
case '!':
- return (scm_read_scsh_block_comment (chr, port));
+ return (scm_read_shebang (chr, port));
case ';':
return (scm_read_commented_expression (chr, port));
case '`':
--
1.7.0.4
