diff options
Diffstat (limited to 'src/backend/parser')
| -rw-r--r-- | src/backend/parser/scan.l | 80 |
1 files changed, 62 insertions, 18 deletions
diff --git a/src/backend/parser/scan.l b/src/backend/parser/scan.l index f972d6ead17..64a389b7680 100644 --- a/src/backend/parser/scan.l +++ b/src/backend/parser/scan.l @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.67 2000/03/13 01:52:06 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/scan.l,v 1.68 2000/03/18 18:03:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -87,10 +87,10 @@ static void addlit(char *ytext, int yleng); * and to eliminate parsing troubles for numeric strings. * Exclusive states: * <xb> binary numeric string - thomas 1997-11-16 - * <xc> extended C-style comments - tgl 1997-07-12 - * <xd> delimited identifiers (double-quoted identifiers) - tgl 1997-10-27 + * <xc> extended C-style comments - thomas 1997-07-12 + * <xd> delimited identifiers (double-quoted identifiers) - thomas 1997-10-27 * <xh> hexadecimal numeric string - thomas 1997-11-16 - * <xq> quoted strings - tgl 1997-07-30 + * <xq> quoted strings - thomas 1997-07-30 */ %x xb @@ -144,7 +144,7 @@ xdinside [^"]+ * have something like plus-slash-star, lex will think this is a 3-character * operator whereas we want to see it as a + operator and a comment start. * The solution is two-fold: - * 1. append {op_and_self}* to xcstart so that it matches as much text as + * 1. append {op_chars}* to xcstart so that it matches as much text as * {operator} would. Then the tie-breaker (first matching rule of same * length) ensures xcstart wins. We put back the extra stuff with yyless() * in case it contains a star-slash that should terminate the comment. @@ -154,7 +154,7 @@ xdinside [^"]+ * SQL92-style comments, which start with dash-dash, have similar interactions * with the operator rule. */ -xcstart \/\*{op_and_self}* +xcstart \/\*{op_chars}* xcstop \*+\/ xcinside ([^*]+)|(\*+[^/]) @@ -166,10 +166,19 @@ identifier {letter}{letter_or_digit}* typecast "::" -/* NB: if you change "self", fix the copy in the operator rule too! */ +/* + * "self" is the set of chars that should be returned as single-character + * tokens. "op_chars" is the set of chars that can make up "Op" tokens, + * which can be one or more characters long (but if a single-char token + * appears in the "self" set, it is not to be returned as an Op). Note + * that the sets overlap, but each has some chars that are not in the other. + * + * If you change either set, adjust the character lists appearing in the + * rule for "operator"! + */ self [,()\[\].;$\:\+\-\*\/\%\^\<\>\=\|] -op_and_self [\~\!\@\#\^\&\|\`\?\$\:\+\-\*\/\%\<\>\=] -operator {op_and_self}+ +op_chars [\~\!\@\#\^\&\|\`\?\$\:\+\-\*\/\%\<\>\=] +operator {op_chars}+ /* we no longer allow unary minus in numbers. * instead we pass it separately to parser. there it gets @@ -202,7 +211,7 @@ horiz_space [ \t\f] newline [\n\r] non_newline [^\n\r] -comment (("--"|"//"){non_newline}*) +comment ("--"{non_newline}*) whitespace ({space}|{comment}) @@ -220,7 +229,7 @@ other . /* DO NOT PUT ANY COMMENTS IN THE FOLLOWING SECTION. * AT&T lex does not properly handle C-style comments in this second lex block. - * So, put comments here. tgl - 1997-09-08 + * So, put comments here. thomas - 1997-09-08 * * Quoted strings must allow some special characters such as single-quote * and newline. @@ -329,23 +338,57 @@ other . {self} { return yytext[0]; } {operator} { - /* Check for embedded slash-star or dash-dash */ - char *slashstar = strstr((char*)yytext, "/*"); - char *dashdash = strstr((char*)yytext, "--"); + /* + * Check for embedded slash-star or dash-dash; those + * are comment starts, so operator must stop there. + * Note that slash-star or dash-dash at the first + * character will match a prior rule, not this one. + */ + int nchars = yyleng; + char *slashstar = strstr((char*)yytext, "/*"); + char *dashdash = strstr((char*)yytext, "--"); if (slashstar && dashdash) { + /* if both appear, take the first one */ if (slashstar > dashdash) slashstar = dashdash; } else if (!slashstar) slashstar = dashdash; - if (slashstar) + nchars = slashstar - ((char*)yytext); + + /* + * For SQL92 compatibility, '+' and '-' cannot be the + * last char of a multi-char operator unless the operator + * contains chars that are not in SQL92 operators. + * The idea is to lex '=-' as two operators, but not + * to forbid operator names like '?-' that could not be + * sequences of SQL92 operators. + */ + while (nchars > 1 && + (yytext[nchars-1] == '+' || + yytext[nchars-1] == '-')) + { + int ic; + + for (ic = nchars-2; ic >= 0; ic--) + { + if (strchr("~!@#&`?$:%^|", yytext[ic])) + break; + } + if (ic >= 0) + break; /* found a char that makes it OK */ + nchars--; /* else remove the +/-, and check again */ + } + + if (nchars < yyleng) { - int nchars = slashstar - ((char*)yytext); + /* Strip the unwanted chars from the token */ yyless(nchars); - /* If what we have left is only one char, and it's + /* + * If what we have left is only one char, and it's * one of the characters matching "self", then * return it as a character token the same way * that the "self" rule would have. @@ -355,8 +398,9 @@ other . return yytext[0]; } + /* Convert "!=" operator to "<>" for compatibility */ if (strcmp((char*)yytext, "!=") == 0) - yylval.str = pstrdup("<>"); /* compatibility */ + yylval.str = pstrdup("<>"); else yylval.str = pstrdup((char*)yytext); return Op; |