Package jflex.core
Class SemCheck
java.lang.Object
jflex.core.SemCheck
Performs simple semantic analysis on regular expressions.
- Version:
- JFlex 1.8.2
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic void
Performs semantic analysis for all expressions.static boolean
isFiniteChoice
(RegExp re) Returns true iff the expression is a finite choice of fixed length expressions.static int
Returns length if expression has fixed length, -1 otherwise.static boolean
maybeEmtpy
(RegExp re) Checks if the expression potentially matches the empty string.
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Constructor Details
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SemCheck
private SemCheck()Prevent instantiation of static-only class
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Method Details
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check
Performs semantic analysis for all expressions.Currently checks for empty expressions only.
- Parameters:
rs
- the reg exps to be checkedf
- the spec file containing the rules
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maybeEmtpy
Checks if the expression potentially matches the empty string.- Parameters:
re
- aRegExp
object.- Returns:
- a boolean.
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length
Returns length if expression has fixed length, -1 otherwise.Negation operators are treated as always variable length.
- Parameters:
re
- aRegExp
object.- Returns:
- a int.
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isFiniteChoice
Returns true iff the expression is a finite choice of fixed length expressions.Negation operators are treated as always variable length.
- Parameters:
re
- aRegExp
object.- Returns:
- a boolean.
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