Building Parsers with Java™

2.5. Terminal Parsers

The examples in this book wrap strings either as assemblies of characters or assemblies of tokens. Each terminal must be geared toward one of these two types of assemblies. Each time a terminal asks an assembly for its nextElement(), the terminal must anticipate receiving either a character or a token; the terminal decides whether the character or token it receives is a match. Figure 2.8 shows the hierarchy of terminals that work with tokens. The subclasses of Terminal in Figure 2.8 are members of the package sjm.parse.tokens.

Figure 2.8. Token terminals. The subclasses of Terminal shown here expect an assembly's elements to be complete tokens.

2.5.1. Using Terminals

For an example of how to use a terminal, consider the ...