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Description |
This module defines the things required by Alex and some other
Alex related things.
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Synopsis |
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Alex requirements
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This is what the lexer manipulates.
| Constructors | AlexInput | | lexPos :: !Position | current position
| lexInput :: String | current input
| lexPrevChar :: !Char | previously read character
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Get the previously lexed character. Same as lexPrevChar. Alex needs this
to be defined to handle "patterns with a left-context".
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Lex a character. No surprises.
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Lex actions
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In the lexer, regular expressions are associated with lex actions who's
task it is to construct the tokens.
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Sometimes regular expressions aren't enough. Alex provides a way to do
arbitrary computations to see if the input matches. This is done with a
lex predicate.
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Conjunction of LexPredicates.
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Disjunction of LexPredicates.
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Negation of LexPredicates.
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Monad operations
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Produced by Haddock version 2.6.0 |