Support for parsing Lisp expression out of strings and streams.

New catenated streams make the Yacc hack possible.

* eval.c (eval_init): Register lisp_parse as intrinsic.

* parser.h (lisp_parse): Declared.

* parser.l: New lexical hack to produce SECRET_ESCAPE_E token.
(regex_parse): Move declaration before statements.
(lisp_parse): New function.

* parser.y (SECRET_ESCAPE_E): New token type.
(spec): New production rule for single expression.

* stream.c (cat_stream_print, cat_get_line, cat_get_char,
cat_get_byte, cat_get_prop): New static functions.
(cat_stream_ops): New static function.
(make_catenated_stream): New function.

* stream.h (make_catenated_stream): Declared.

1 files changed, 2 insertions, 1 deletions

diff --git a/parser.y b/parser.y
index c82ede7c..8ff5f3cb 100644
--- a/parser.y
+++ b/parser.y
@@ -75,7 +75,7 @@ static val parsed_spec;
 %token <lineno> MOD MODLAST DEFINE TRY CATCH FINALLY
 %token <lineno> ERRTOK /* deliberately not used in grammar */
 %token <lineno> HASH_BACKSLASH HASH_SLASH DOTDOT HASH_H
-%token <lineno> SECRET_ESCAPE_R
+%token <lineno> SECRET_ESCAPE_R SECRET_ESCAPE_E
 
 %token <val> NUMBER METANUM
 
@@ -117,6 +117,7 @@ static val parsed_spec;
 spec : clauses                  { parsed_spec = $1; }
      | /* empty */              { parsed_spec = nil; }
      | SECRET_ESCAPE_R regexpr  { parsed_spec = $2; end_of_regex(); }
+     | SECRET_ESCAPE_E expr     { parsed_spec = $2; }
      | error '\n'               { parsed_spec = nil;
                                   if (errors >= 8)
                                     YYABORT;