Package jflex.core
Class RegExp
java.lang.Object
jflex.core.RegExp
Stores a regular expression of rules section in a JFlex-specification.
This base class has no content other than its type.
- Version:
- JFlex 1.9.1
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic RegExp
anyChar()
Returns a regexp that matches any character:[^]
private static boolean
checkJPartStart
(int type, int c) Check whether a character is a member of the give char class type.static RegExp1
Confirms that the parameter is a RegExp1 of type sym.PRIMCLASS.expandPreClasses
(Map<Integer, IntCharSet> cache, CharClasses cl, boolean caseless) Expand pre-defined character classes into primitive IntCharSet classes.private static IntCharSet
getPreClass
(Map<Integer, IntCharSet> preclassCache, CharClasses charClasses, int type) Compute and memoize a pre-defined character class.boolean
Find out if this regexp is a char class or equivalent to one.final void
makeCCLs
(CharClasses c, boolean caseless) Make character class partitions based on the classes mentioned in this regexp.final RegExp
normaliseCCLs
(File f, int line) Normalise the regular expression to eliminate compound character class expression (compute their content).final RegExp
Normalise the regular expression to eliminate macro use (expand them).static IntCharSet
performClassOp
(int op, IntCharSet l, IntCharSet r, RegExp ctxt) Performs the given set operation on the twoIntCharSet
parameters.Returns a String-representation of this regular expression with the specified indentation.final RegExp
Recursively convert tilde (upto) expressions into negation and star.final RegExp
rev()
Creates a new regexp that matches the reverse text of this one.(package private) static String
Reverses a string.int
The approximate number of NFA states this expression will need (only works correctly after macro expansion and without negation)toString()
typeName()
String representation of the type of this regular expression.
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Field Details
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type
int typeThe type of the regular expression. This field will be filled with values from class sym.java (generated by cup)
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Constructor Details
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RegExp
public RegExp(int type) Create a new regular expression of the specified type.- Parameters:
type
- a value from the cup generated class sym.
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Method Details
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print
Returns a String-representation of this regular expression with the specified indentation.- Parameters:
tab
- a String that should contain only space characters and that is inserted in front of standard String-representation pf this object.- Returns:
- a
String
object.
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toString
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typeName
String representation of the type of this regular expression. -
isCharClass
public boolean isCharClass()Find out if this regexp is a char class or equivalent to one.- Returns:
- true if the regexp is equivalent to a char class.
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size
The approximate number of NFA states this expression will need (only works correctly after macro expansion and without negation)- Parameters:
macros
- macro table for expansion- Returns:
- a int.
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revString
Reverses a string. -
resolveTilde
Recursively convert tilde (upto) expressions into negation and star.- Returns:
- new RegExp equivalent to the current one, but without upto expressions.
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anyChar
Returns a regexp that matches any character:[^]
- Returns:
- the regexp for
[^]
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checkPrimClass
Confirms that the parameter is a RegExp1 of type sym.PRIMCLASS.- Parameters:
r
- the RegExp to check- Returns:
- r cast to RegExp1
- Throws:
CharClassException
- if r is not a RegExp1 or of type sym.PRIMCLASS.
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performClassOp
Performs the given set operation on the twoIntCharSet
parameters.- Parameters:
op
- the operation to perform (as @{link sym} constant)l
- the left operator of the expressionr
- the right operator of the expressionctxt
- the regular expression containing the provided operator- Returns:
- a new
IntCharSet
- Throws:
RegExpException
- forctxt
if the operator is not supported
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normaliseMacros
Normalise the regular expression to eliminate macro use (expand them).- Returns:
- a regexp that contains no
sym.MACROUSE
.
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normaliseCCLs
Normalise the regular expression to eliminate compound character class expression (compute their content).- Parameters:
f
- the spec file containing the regular expression (for error reporting)line
- the line number of the regular expression (for error reporting)- Returns:
- a regexp where all char classes are primitive
IntCharSet
classes.
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expandPreClasses
Expand pre-defined character classes into primitive IntCharSet classes.- Parameters:
cache
- memoized pre-defined character class expansionscl
- character class partitions- Returns:
- the expanded regular expression
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checkJPartStart
private static boolean checkJPartStart(int type, int c) Check whether a character is a member of the give char class type.- Parameters:
type
- the type of the character class (sym.JLETTERCLASS
orsym.JLETTERDIGITCLASS
)c
- the character to check- Returns:
- true if the character is a member of the class
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getPreClass
private static IntCharSet getPreClass(Map<Integer, IntCharSet> preclassCache, CharClasses charClasses, int type) Compute and memoize a pre-defined character class.- Parameters:
preclassCache
- memoized pre-defined character class expansionscharClasses
- character class partitionstype
- the type of the predefined character class- Returns:
- the expanded IntCharSet for the class
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makeCCLs
Make character class partitions based on the classes mentioned in this regexp.Assumption: regexp is normalised.
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rev
Creates a new regexp that matches the reverse text of this one.- Returns:
- the reverse regexp
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