Re: massive quotes?

Attached is a proof-of-concept diff that makes the main SQL parser
accept quoted strings in the style recently discussed ($Q$ ... $Q$).
To complete the feature, we'd need to make the plpgsql parser do the
same, update psql to understand this, update pg_dump to use this style
of quoting for function bodies (and perhaps other things?), and update
the documentation.  The last is a nontrivial project all by itself.
Anybody want to run with this football?
        regards, tom lane


*** src/backend/parser/scan.l.orig    Sun Aug  3 23:00:44 2003
--- src/backend/parser/scan.l    Sun Sep 14 01:38:55 2003
***************
*** 39,44 ****
--- 39,46 ----  static int        xcdepth = 0;    /* depth of nesting in slash-star comments */ 
+ static char       *hqstart;        /* current here-document start string */
+  /*  * literalbuf is used to accumulate literal values when multiple rules  * are needed to parse a single literal.
Callstartlit to reset buffer
 
***************
*** 95,100 ****
--- 97,103 ----  *  <xd> delimited identifiers (double-quoted identifiers)  *  <xh> hexadecimal numeric string  *  <xq>
quotedstrings
 
+  *  <hq> here-document-style quoted strings  */  %x xb
***************
*** 102,107 ****
--- 105,111 ---- %x xd %x xh %x xq
+ %x hq  /* Bit string  * It is tempting to scan the string for only those characters
***************
*** 141,146 ****
--- 145,157 ---- xqoctesc        [\\][0-7]{1,3} xqcat            {quote}{whitespace_with_newline}{quote} 
+ /* Here-document-style quotes
+  * The quoted string starts with $letters$ and extends to the first occurrence
+  * of an identical string.  There is *no* processing of the quoted text.
+  */
+ hqdelim            \$[A-Za-z]*\$
+ hqinside        [^$]+
+  /* Double quote  * Allows embedded spaces and other special characters into identifiers.  */
***************
*** 387,392 ****
--- 398,432 ----                 } <xq><<EOF>>        { yyerror("unterminated quoted string"); } 
+ {hqdelim}        {
+                     token_start = yytext;
+                     hqstart = pstrdup(yytext);
+                     BEGIN(hq);
+                     startlit();
+                 }
+ <hq>{hqdelim}    {
+                     if (strcmp(yytext, hqstart) == 0)
+                     {
+                         pfree(hqstart);
+                         BEGIN(INITIAL);
+                         yylval.str = litbufdup();
+                         return SCONST;
+                     }
+                     /*
+                      * When we fail to match $...$ to hqstart, transfer
+                      * the $... part to the output, but put back the final
+                      * $ for rescanning.  Consider $delim$...$junk$delim$
+                      */
+                     addlit(yytext, yyleng-1);
+                     yyless(yyleng-1);
+                 }
+ <hq>{hqinside}  {
+                     addlit(yytext, yyleng);
+                 }
+ <hq>.           {
+                     addlitchar(yytext[0]);
+                 }
+ <hq><<EOF>>        { yyerror("unterminated special-quoted string"); }  {xdstart}        {
token_start= yytext;