Rule alternative descriptor. This describes one alternative in a grammar production. An alternative is one complete list of matchable tokens.
In a 'grammar' statement, alternatives are delimited by '|' symbols at the top level. Each group of tokens set off by '|' symbols is one alternative.
When '|' symbols are grouped with parentheses in a 'grammar' statement, the compiler "flattens" the grouping by expanding out the parenthesized groups until it has entirely top-level alternatives. So, at the level of a GrammarProd object, there's no such thing as parentheses or nested '|' symbols.
GrammarAltInfo : object
Superclass Tree (in declaration order)
Summary of Properties
Summary of Methods
The 'badness' value associated with the alternative. A value of zero means that there's no badness.
the "match object" class - this is the class that GrammarProd.parseTokens() instantiates to represent a match to this alternative in the match list that the method returns
The token descriptor list. This is a list of zero or more GrammarAltTokInfo objects describing the tokens making up this rule.
construct (score, badness, matchObj, toks, ...)
Constructor. GrammarProd.getGrammarInfo() calls this once for each alternative making up the production, passing in the values that define the alternative. Note that we have a '...' in our argument list so that we'll be compatible with any future GrammarProd versions that add additional arguments - we won't do anything with the extra arguments, but we'll harmlessly ignore them, so code compiled with this library version will continue to work correctly.
TADS 3 Library Manual
Generated on 5/16/2013 from TADS version 3.1.3