Module: ANTLR3::Constants

Overview

A simple module to keep track of the various built-in token types, channels, and token names used by ANTLR throughout the runtime library.

Constant Summary

EOF_TOKEN =

End of File / End of Input character and token type

CommonToken.new( EOF ).freeze
INVALID_TOKEN =
CommonToken.new( INVALID_TOKEN_TYPE ).freeze
SKIP_TOKEN =
CommonToken.new( INVALID_TOKEN_TYPE ).freeze
DEFAULT =

the channel to which most tokens will be assigned

DEFAULT_CHANNEL = DEFAULT_TOKEN_CHANNEL = :default
HIDDEN =

the channel for tokens which should not be passed to a parser by a token stream

HIDDEN_CHANNEL  = :hidden
MEMO_RULE_FAILED =

flag used by recognizers during memoization to represent a previous prediction failure

2
MEMO_RULE_UNKNOWN =

flag used by recognizers during memoization to indicate that the rule has not been memoized yet

1
INVALID_TOKEN_TYPE =

built-in token types used internally by ANTLR3

0
EOF =
1
UP =

Imaginary tree-navigation token type indicating the ascent after moving through the children of a node

3
DOWN =

Imaginary tree-navigation token type indicating a descent into the children of a node

2
EOR_TOKEN_TYPE =

End of Rule (used internally by DFAs)

1
MIN_TOKEN_TYPE =

The smallest possible value of non-builtin ANTLR-generated token types

4
BUILT_IN_TOKEN_NAMES =

A hash mapping built in token types to their respective names returning a string "<UNKNOWN: #type>" for non-builtin token types

Hash.new do |h, k|
  "<UNKNOWN: #{ k }>"
end