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Similar to tokens, which are connecting characters, productions connect tokens. Regular sequences or alternatives of token sequences can be formulated as a rule, that means as a production.
Definitions of productions are based on three kinds of elements:
1a) Literal tokens directly defined inside of a production
1b) Named tokens, defined on the token page
Remark: The text, which a token matched, is accessible by xState.str()
About 1a) Literal tokens directly defined inside of a production
Simple words of the natural language or key words of a formalized language, punctuation marks, operators etc. can, but must not be defined on the token page. These literal token can be defined directly inside of a production by including them into quotes.
"TETRA" matches: TETRA
";" matches: ;
If the quotation mark shall be used as a component of a literal token, then a backslash '\' must be put in front of character to distinguish it of the enclosing quotation marks. The backslash must as well be put in front a backslash.
"\"" matches: "
"\\" matches: \
About 1b) Named tokens, defined on the token page
The definition of complex token was described above. Inside of a production the names of already defined tokens can be used.
About 2. Other productions
The definition of a production can be based on the definitions of other productions by using the names of them.
Production1 ::= "hello" | "good bye"
Production2 ::= "world"
Production3 ::= Production1 Production2
This page belongs to the TextTransformer Documentation
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