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style: simplify the scanning of type tags

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* src/scan-gram.l: Remove the rule for simple tags: the "complex" case
subsumes it.  It was more efficient, but duplicated the code for a
negligible benefit.
This commit is contained in:
Akim Demaille
2013-02-21 14:32:16 +01:00
parent 6574576cfb
commit e52ddf820b
1 changed files with 11 additions and 19 deletions
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30
src/scan-gram.l
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@@ -112,7 +112,12 @@ static void unexpected_newline (boundary, char const *);
/* A identifier was just read in directives/rules. Special state /* A identifier was just read in directives/rules. Special state
to capture the sequence 'identifier :'. */ to capture the sequence 'identifier :'. */
%x SC_AFTER_IDENTIFIER %x SC_AFTER_IDENTIFIER
/* A complex tag, with nested angles brackets. */
/* POSIX says that a tag must be both an id and a C union member, but
historically almost any character is allowed in a tag. We
disallow NUL, as this simplifies our implementation. We match
angle brackets in nested pairs: several languages use them for
generics/template types. */
%x SC_TAG %x SC_TAG
/* Four types of user code: /* Four types of user code:
@@ -133,13 +138,6 @@ notletter [^.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]{-}[%\{]
id {letter}({letter}|[-0-9])* id {letter}({letter}|[-0-9])*
int [0-9]+ int [0-9]+
/* POSIX says that a tag must be both an id and a C union member, but
historically almost any character is allowed in a tag. We disallow
NUL, as this simplifies our implementation. We disallow angle
bracket to match them in nested pairs: several languages use them
for generics/template types. */
tag [^\0<>]+
/* Zero or more instances of backslash-newline. Following GCC, allow /* Zero or more instances of backslash-newline. Following GCC, allow
white space between the backslash and the newline. */ white space between the backslash and the newline. */
splice (\\[ \f\t\v]*\n)* splice (\\[ \f\t\v]*\n)*
@@ -325,13 +323,6 @@ eqopt ([[:space:]]*=)?
/* A type. */ /* A type. */
"<*>" return TAG_ANY; "<*>" return TAG_ANY;
"<>" return TAG_NONE; "<>" return TAG_NONE;
"<"{tag}">" {
obstack_grow (&obstack_for_string, yytext + 1, yyleng - 2);
STRING_FINISH;
val->uniqstr = uniqstr_new (last_string);
STRING_FREE;
return TAG;
}
"<" { "<" {
nesting = 0; nesting = 0;
token_start = loc->start; token_start = loc->start;
@@ -559,10 +550,11 @@ eqopt ([[:space:]]*=)?
<<EOF>> unexpected_eof (token_start, "'"); <<EOF>> unexpected_eof (token_start, "'");
} }
/*-----------------------------------------------------------.
| Scanning a Bison nested tag. The initial angle bracket is |
| already eaten. | /*--------------------------------------------------------------.
`-----------------------------------------------------------*/ | Scanning a tag. The initial angle bracket is already eaten. |
`--------------------------------------------------------------*/
<SC_TAG> <SC_TAG>
{ {