Productions or non-terminal symbols

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Introduction > Productions or non-terminal symbols


The non-terminal symbols are described by rules, which determine the order of the terminal symbols. Such a rule is called a Production. To formulate a production, TETRA has is a script language with a syntax similar to that of the regular expressions. While the elements of the regular expressions are characters, a production describes the concatenation, repetition etc. of token elements. In this regard productions are patterns of patterns.


A production has two tasks. Beneath of the just explained task:


1. to determine, what will be recognized in a text

2. to determine, what will be done with the recognized text


Point 2 denotes the synthesis mentioned above.


Corresponding to the two tasks, there are two kinds of sections inside the definition of a production, which are separated by special brackets. In the example presented on the next page the brackets "{{" and "}}" are used, to separate the semantic actions denoted by point 2 from the syntactical code (point 1).




This page belongs to the TextTransformer Documentation

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