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* String interpolation. Expressions like

Browse source 
"--with-freetype2-library=" + freetype + "/lib"

  can now be written as

    "--with-freetype2-library=${freetype}/lib"

  An arbitrary expression can be enclosed within ${...}, not just
  identifiers.

* Escaping in string literals: \n, \r, \t interpreted as in C, any
  other character following \ is interpreted as-is.
  
* Newlines are now allowed in string literals.
This commit is contained in:
Eelco Dolstra 2006-05-01 14:01:47 +00:00
parent 6cecad2be0
commit 0064599a27
7 changed files with 88 additions and 15 deletions
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41
src/libexpr/lexer.l
View file

@ -3,6 +3,9 @@
%option never-interactive
%x STRING
%{
#include <string.h>
#include <aterm2.h>
@ -28,6 +31,9 @@ static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
}
}
ATerm toATerm(const char * s);
ATerm unescapeStr(const char * s);
#define YY_USER_INIT initLoc(yylloc)
#define YY_USER_ACTION adjustLoc(yylloc, yytext, yyleng);
@ -36,7 +42,6 @@ static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
ID [a-zA-Z\_][a-zA-Z0-9\_\']*
INT [0-9]+
STR \"[^\n\"]*\"
PATH [a-zA-Z0-9\.\_\-\+]*(\/[a-zA-Z0-9\.\_\-\+]+)+
URI [a-zA-Z][a-zA-Z0-9\+\-\.]*\:[a-zA-Z0-9\%\/\?\:\@\&\=\+\$\,\-\_\.\!\~\*\']+
@ -61,19 +66,27 @@ inherit { return INHERIT; }
\/\/ { return UPDATE; }
\+\+ { return CONCAT; }
{ID} { yylval->t = ATmake("<str>", yytext); return ID; /* !!! alloc */ }
{ID} { yylval->t = toATerm(yytext); return ID; /* !!! alloc */ }
{INT} { int n = atoi(yytext); /* !!! overflow */
yylval->t = ATmake("<int>", n);
return INT;
}
{STR} { int len = strlen(yytext);
yytext[len - 1] = 0;
yylval->t = ATmake("<str>", yytext + 1);
yytext[len - 1] = '\"';
return STR; /* !!! alloc */
\" { BEGIN(STRING); return '"'; }
<STRING>([^\$\"\\]|\\.|\$[^\{\$])+ {
/* Note: a dollar *is* allowed as-is in a string, as long as it's
not followed by a open brace. This should probably be disallowed
eventually. */
yylval->t = unescapeStr(yytext); /* !!! alloc */
return STR;
}
{PATH} { yylval->t = ATmake("<str>", yytext); return PATH; /* !!! alloc */ }
{URI} { yylval->t = ATmake("<str>", yytext); return URI; /* !!! alloc */ }
<STRING>\$\{ { BEGIN(INITIAL); return DOLLAR_CURLY; }
<STRING>\" { BEGIN(INITIAL); return '"'; }
<STRING>. return yytext[0]; /* just in case: shouldn't be reached */
{PATH} { yylval->t = toATerm(yytext); return PATH; /* !!! alloc */ }
{URI} { yylval->t = toATerm(yytext); return URI; /* !!! alloc */ }
[ \t\n]+ /* eat up whitespace */
\#[^\n]* /* single-line comments */
@ -83,3 +96,13 @@ inherit { return INHERIT; }
%%
/* Horrible, disgusting hack: allow the parser to set the scanner
start condition back to STRING. Necessary in interpolations like
"foo${expr}bar"; after the close brace we have to go back to the
STRING state. */
void backToString(yyscan_t scanner)
{
struct yyguts_t * yyg = (struct yyguts_t*) scanner;
BEGIN(STRING);
}