* String interpolation. Expressions like

"--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

View file

@ -231,7 +231,7 @@ static ATerm concatStrings(EvalState & state, const ATermVector & args)
{
ATermList context = ATempty;
ostringstream s;
bool isPath;
bool isPath = false;
for (ATermVector::const_iterator i = args.begin(); i != args.end(); ++i) {
bool isPath2;
@ -449,6 +449,14 @@ Expr evalExpr2(EvalState & state, Expr e)
return makeList(ATconcat(l1, l2));
}
/* String concatenation. */
ATermList es;
if (matchConcatStrings(e, es)) {
ATermVector args;
for (ATermIterator i(es); i; ++i) args.push_back(*i);
return concatStrings(state, args);
}
/* Barf. */
throw badTerm("invalid expression", e);
}

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);
}

View file

@ -19,6 +19,7 @@ SubPath | Expr Expr | Expr |
OpHasAttr | Expr string | Expr |
OpPlus | Expr Expr | Expr |
OpConcat | Expr Expr | Expr |
ConcatStrings | ATermList | Expr |
Call | Expr Expr | Expr |
Select | Expr string | Expr |
Var | string | Expr |

View file

@ -71,9 +71,29 @@ const char * getPath(ParseData * data)
return data->path.c_str();
}
int yyparse(yyscan_t scanner, ParseData * data);
Expr unescapeStr(const char * s)
{
string t;
char c;
while (c = *s++) {
if (c == '\\') {
assert(*s);
c = *s++;
if (c == 'n') t += "\n";
else if (c == 'r') t += "\r";
else if (c == 't') t += "\t";
else t += c;
}
else t += c;
}
return makeStr(toATerm(t));
}
int yyparse(yyscan_t scanner, ParseData * data);
} /* end of C functions */
static void checkAttrs(ATermMap & names, ATermList bnds)
{

View file

@ -25,6 +25,7 @@ void parseError(void * data, char * error, int line, int column);
ATerm absParsedPath(void * data, ATerm t);
ATerm fixAttrs(int recursive, ATermList as);
const char * getPath(void * data);
void backToString(yyscan_t scanner);
void yyerror(YYLTYPE * loc, yyscan_t scanner, void * data, char * s)
{
@ -73,9 +74,10 @@ static void freeAndUnprotect(void * p)
%type <t> start expr expr_function expr_if expr_op
%type <t> expr_app expr_select expr_simple bind inheritsrc formal
%type <ts> binds ids expr_list formals
%type <ts> binds ids expr_list formals string_parts
%token <t> ID INT STR PATH URI
%token IF THEN ELSE ASSERT WITH LET REC INHERIT EQ NEQ AND OR IMPL
%token DOLLAR_CURLY /* == ${ */
%nonassoc IMPL
%left OR
@ -142,7 +144,12 @@ expr_select
expr_simple
: ID { $$ = makeVar($1); }
| INT { $$ = makeInt(ATgetInt((ATermInt) $1)); }
| STR { $$ = makeStr($1); }
| '"' string_parts '"' {
/* For efficiency, and to simplify parse trees a bit. */
if ($2 == ATempty) $$ = makeStr(toATerm(""));
else if (ATgetNext($2) == ATempty) $$ = ATgetFirst($2);
else $$ = makeConcatStrings(ATreverse($2));
}
| PATH { $$ = makePath(absParsedPath(data, $1)); }
| URI { $$ = makeUri($1); }
| '(' expr ')' { $$ = $2; }
@ -157,6 +164,12 @@ expr_simple
| '[' expr_list ']' { $$ = makeList($2); }
;
string_parts
: string_parts STR { $$ = ATinsert($1, $2); }
| string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = ATinsert($1, $3); }
| { $$ = ATempty; }
;
binds
: binds bind { $$ = ATinsert($1, $2); }
| { $$ = ATempty; }

View file

@ -1 +1 @@
Str("foobar/a/b/c/d/foo/xyzzy/foo.txt/../foo/x/y")
Str("foobar/a/b/c/d/foo/xyzzy/foo.txt/../foo/x/yescape: \"quote\" \n \\end\nof\nlinefoobarblaat")

View file

@ -1 +1,9 @@
"foo" + "bar" + toString (/a/b + /c/d) + (/foo/bar + "/../xyzzy/." + "/foo.txt") + ("/../foo" + /x/y)
"foo" + "bar"
+ toString (/a/b + /c/d)
+ (/foo/bar + "/../xyzzy/." + "/foo.txt")
+ ("/../foo" + /x/y)
+ "escape: \"quote\" \n \\"
+ "end
of
line"
+ "foo${if true then "b${"a" + "r"}" else "xyzzy"}blaat"