| [ << ] | [ < ] | [ Up ] | [ > ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |
4.6 The Lexical Analyzer Function yylex
The lexical analyzer function, yylex, recognizes tokens from
the input stream and returns them to the parser. Bison does not create
this function automatically; you must write it so that yyparse can
call it. The function is sometimes referred to as a lexical scanner.
In simple programs, yylex is often defined at the end of the
Bison grammar file. If yylex is defined in a separate source
file, you need to arrange for the token-type macro definitions to be
available there. To do this, use the ‘-d’ option when you run
Bison, so that it will write these macro definitions into the separate
parser header file, ‘name.tab.h’, which you can include in
the other source files that need it. See section Invoking Bison.
4.6.1 Calling Convention for yylex | How yyparse calls yylex.
| |
| 4.6.2 Semantic Values of Tokens | How yylex must return the semantic value
of the token it has read.
| |
| 4.6.3 Textual Locations of Tokens | How yylex must return the text location
(line number, etc.) of the token, if the
actions want that.
| |
| 4.6.4 Calling Conventions for Pure Parsers | How the calling convention differs in a pure parser (see section A Pure (Reentrant) Parser). |
| [ << ] | [ < ] | [ Up ] | [ > ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |
This document was generated on December 1, 2013 using texi2html 5.0.