More Than One Value Type ------------------------ In most programs, you will need different data types for different kinds of tokens and groupings. For example, a numeric constant may need type `int' or `long', while a string constant needs type `char *', and an identifier might need a pointer to an entry in the symbol table. To use more than one data type for semantic values in one parser, Bison requires you to do two things: * Specify the entire collection of possible data types, with the `%union' Bison declaration (*note The Collection of Value Types: Union Decl.). * Choose one of those types for each symbol (terminal or nonterminal) for which semantic values are used. This is done for tokens with the `%token' Bison declaration (Note: Token Type Names.) and for groupings with the `%type' Bison declaration (Note: Nonterminal Symbols.).
Dirfile and infopages generated Sat Dec 3 02:07:54 2005