Re: primary encoding and source encoding

Hi,

At Fri, 9 Nov 2007 05:42:47 +0900,
David Flanagan wrote in [ruby-core:13315]:
> Q1) In step 1 above, should the default primary encoding come from the 
> locale environment variables (LC_ALL, LC_CTYPE, and LANG) instead of 
> defaulting to ASCII?

It's planned, but we have no mappings from locale name to
encoding name.  Attached is a quick hack I tried the week
before last.

> Q2) If yes, to the above, then shouldn't we drop step 5 above?  If my 
> locale specifies UTF-8 as my primary encoding then I don't think that 
> should be changed just because I run a script developed by a Japanese 
> programmer and encoded in EUC-JP.

Yes, I think.


Index: ruby.c
===================================================================
--- ruby.c	(revision 13847)
+++ ruby.c	(working copy)
@@ -133,4 +133,34 @@ usage(const char *name)
 }
 
+static rb_encoding *
+locale_encoding(void)
+{
+    const char *lang = getenv("LC_ALL");
+    int idx = 0;
+    rb_encoding *enc;
+
+    if (!lang) lang = getenv("LANG");
+    if (lang && (lang = strchr(lang, '.')) != 0) {
+	const char *at = strchr(++lang, '@');
+	int len = (at ? at - lang : strlen(lang));
+	char buf[32];
+	if (len < sizeof(buf)) {
+	    MEMCPY(buf, lang, char, len);
+	    buf[len] = 0;
+	    idx = rb_enc_find_index(buf);
+	    if (idx < 0 && len > 3 &&
+		(strncasecmp(buf, "euc", 3) == 0 ||
+		 strncasecmp(buf, "utf", 3) == 0) &&
+		buf[3]) {
+		MEMMOVE(buf + 4, buf + 3, char, len - 2);
+		buf[3] = '-';
+		idx = rb_enc_find_index(buf);
+	    }
+	}
+    }
+    enc = rb_enc_from_index(idx);
+    return enc ? enc : rb_enc_default();
+}
+
 extern VALUE rb_load_path;
 
@@ -851,5 +881,5 @@ process_options(VALUE arg)
     NODE *tree = 0;
     VALUE parser;
-    VALUE encoding;
+    rb_encoding *enc;
     const char *s;
     int i = proc_options(argc, argv, opt);
@@ -980,10 +1010,10 @@ process_options(VALUE arg)
 
     if (opt->enc_index >= 0) {
-	encoding = rb_enc_from_encoding(rb_enc_from_index(opt->enc_index));
+	enc = rb_enc_from_index(opt->enc_index);
     }
     else {
-	encoding = rb_parser_encoding(parser);
+	enc = locale_encoding();
     }
-    rb_set_primary_encoding(encoding);
+    rb_set_primary_encoding(rb_enc_from_encoding(enc));
 
     return (VALUE)tree;


-- 
Nobu Nakada