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(bison.info)Declarations

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Bison Declarations
==================

   The "Bison declarations" section of a Bison grammar defines the
symbols used in formulating the grammar and the data types of semantic
values.  Note: Symbols.

   All token type names (but not single-character literal tokens such as
`'+'' and `'*'') must be declared.  Nonterminal symbols must be
declared if you need to specify which data type to use for the semantic
value (Note: More Than One Value Type.).

   The first rule in the file also specifies the start symbol, by
default.  If you want some other symbol to be the start symbol, you
must declare it explicitly (*note Languages and Context-Free Grammars:
Language and Grammar.).

Token Decl

Declaring terminal symbols.

Precedence Decl

Declaring terminals with precedence and associativity.

Union Decl

Declaring the set of all semantic value types.

Type Decl

Declaring the choice of type for a nonterminal symbol.

Expect Decl

Suppressing warnings about shift/reduce conflicts.

Start Decl

Specifying the start symbol.

Pure Decl

Requesting a reentrant parser.

Decl Summary

Table of all Bison declarations.