diff options
Diffstat (limited to 'doc/flex.info-6')
| -rw-r--r-- | doc/flex.info-6 | 49 |
1 files changed, 44 insertions, 5 deletions
diff --git a/doc/flex.info-6 b/doc/flex.info-6 index 4af8802..04f95d8 100644 --- a/doc/flex.info-6 +++ b/doc/flex.info-6 @@ -1,4 +1,4 @@ -This is flex.info, produced by makeinfo version 4.3d from flex.texi. +This is flex.info, produced by makeinfo version 4.5 from flex.texi. INFO-DIR-SECTION Programming START-INFO-DIR-ENTRY @@ -826,7 +826,7 @@ unnamed-faq-100 Vern -File: flex.info, Node: unnamed-faq-101, Prev: unnamed-faq-100, Up: FAQ +File: flex.info, Node: unnamed-faq-101, Next: What is the difference between YYLEX_PARAM and YY_DECL?, Prev: unnamed-faq-100, Up: FAQ unnamed-faq-101 =============== @@ -857,6 +857,40 @@ unnamed-faq-101 Vern +File: flex.info, Node: What is the difference between YYLEX_PARAM and YY_DECL?, Next: Why do I get "conflicting types for yylex" error?, Prev: unnamed-faq-101, Up: FAQ + +What is the difference between YYLEX_PARAM and YY_DECL? +======================================================= + + YYLEX_PARAM is not a flex symbol. It is for Bison. It tells Bison to +pass extra params when it calls yylex() from the parser. + + YY_DECL is the Flex declaration of yylex. The default is similar to +this: + + + #define int yy_lex () + + +File: flex.info, Node: Why do I get "conflicting types for yylex" error?, Next: How do I access the values set in a Flex action from within a Bison action?, Prev: What is the difference between YYLEX_PARAM and YY_DECL?, Up: FAQ + +Why do I get "conflicting types for yylex" error? +================================================= + + This is a compiler error regarding a generated Bison parser, not a +Flex scanner. It means you need a prototype of yylex() in the top of +the Bison file. Be sure the prototype matches YY_DECL. + + +File: flex.info, Node: How do I access the values set in a Flex action from within a Bison action?, Prev: Why do I get "conflicting types for yylex" error?, Up: FAQ + +How do I access the values set in a Flex action from within a Bison action? +=========================================================================== + + With $1, $2, $3, etc. These are called "Semantic Values" in the +Bison manual. See *Note Top: (bison)Top. + + File: flex.info, Node: Appendices, Next: Indices, Prev: FAQ, Up: Top Appendices @@ -1064,11 +1098,15 @@ the actions will be sent through m4. Please follow these rules to protect your code from unwanted `m4' processing. * Do not use symbols that begin with, `m4_', such as, `m4_define', - or `m4_include', since those are reserved for `m4' macro names. + or `m4_include', since those are reserved for `m4' macro names. If + for some reason you need m4_ as a prefix, use a preprocessor + #define to get your symbol past m4 unmangled. * Do not use the strings `[[' or `]]' anywhere in your code. The - former is not valid in C, except within comments, but the latter - is valid in code such as `x[y[z]]'. + former is not valid in C, except within comments and strings, but + the latter is valid in code such as `x[y[z]]'. The solution is + simple. To get the literal string `"]]"', use `"]""]"'. To get the + array notation `x[y[z]]', use `x[y[z] ]'. `m4' is only required at the time you run `flex'. The generated @@ -1077,6 +1115,7 @@ scanner is ordinary C or C++, and does _not_ require `m4'. ---------- Footnotes ---------- (1) The use of m4 is subject to change in future revisions of flex. +It is not part of the public API of flex. Do not depend on it. File: flex.info, Node: Indices, Prev: Appendices, Up: Top |