com.oracle.truffle.regex

Class RegexLanguage

java.lang.Object

com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

com.oracle.truffle.regex.RegexLanguage

public final class RegexLanguage
extends com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

Truffle Regular Expression Language

This language represents classic regular expressions. It accepts regular expressions in the following format: options/regex/flags, where options is a comma-separated list of key-value pairs which affect how the regex is interpreted (see RegexOptions), and /regex/flags is equivalent to the popular regular expression literal format found in e.g. JavaScript or Ruby.

When parsing a regular expression, TRegex will return a CallTarget, which, when called, will yield one of the following results:

• a TruffleNull object, indicating that TRegex cannot handle the given regex
• a RegexObject, which can be used to match the given regex
• a RegexSyntaxException may be thrown to indicate a syntax error. This exception is an AbstractTruffleException with exception type ExceptionType.PARSE_ERROR.

An example of how to parse a regular expression:

 Object regex;
 try {
     regex = getContext().getEnv().parseInternal(Source.newBuilder("regex", "Flavor=ECMAScript/(a|(b))c/i", "myRegex").mimeType("application/tregex").internal(true).build()).call();
 } catch (AbstractTruffleException e) {
     if (InteropLibrary.getUncached().getExceptionType(e) == ExceptionType.PARSE_ERROR) {
         // handle parser error
     } else {
         // fatal error, this should never happen
     }
 }
 if (InteropLibrary.getUncached().isNull(regex)) {
     // regex is not supported by TRegex, fall back to a different regex engine
 }
 

Regex matcher usage example in pseudocode:

 
 regex = <matcher from previous example>
 assert(regex.pattern == "(a|(b))c")
 assert(regex.flags.ignoreCase == true)
 assert(regex.groupCount == 3)

 result = regex.exec("xacy", 0)
 assert(result.isMatch == true)
 assertEquals([result.getStart(0), result.getEnd(0)], [ 1,  3])
 assertEquals([result.getStart(1), result.getEnd(1)], [ 1,  2])
 assertEquals([result.getStart(2), result.getEnd(2)], [-1, -1])

 result2 = regex.exec("xxx", 0)
 assert(result2.isMatch == false)
 // result2.getStart(...) and result2.getEnd(...) are undefined
 
 

Debug loggers: Loggers.

See Also:

RegexOptions, RegexObject, Loggers

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RegexLanguage.RegexContext

Nested classes/interfaces inherited from class com.oracle.truffle.api.TruffleLanguage

com.oracle.truffle.api.TruffleLanguage.ContextLocalFactory<C,T>, com.oracle.truffle.api.TruffleLanguage.ContextLocalProvider<C>, com.oracle.truffle.api.TruffleLanguage.ContextPolicy, com.oracle.truffle.api.TruffleLanguage.ContextReference<C>, com.oracle.truffle.api.TruffleLanguage.ContextThreadLocalFactory<C,T>, com.oracle.truffle.api.TruffleLanguage.Env, com.oracle.truffle.api.TruffleLanguage.ExitMode, com.oracle.truffle.api.TruffleLanguage.InlineParsingRequest, com.oracle.truffle.api.TruffleLanguage.LanguageReference<L extends com.oracle.truffle.api.TruffleLanguage>, com.oracle.truffle.api.TruffleLanguage.ParsingRequest, com.oracle.truffle.api.TruffleLanguage.Registration

Field Summary

Fields

Modifier and Type	Field and Description
static String	ID
static String	MIME_TYPE
static String	NAME
RegexParserGlobals	parserGlobals

Fields inherited from class com.oracle.truffle.api.TruffleLanguage

locals

Constructor Summary

Constructors

Constructor and Description
RegexLanguage()

Method Summary

Modifier and Type	Method and Description
protected RegexLanguage.RegexContext	createContext(com.oracle.truffle.api.TruffleLanguage.Env env)
GroupBoundaries[]	getCachedGroupBoundaries()
protected Object	getScope(RegexLanguage.RegexContext context)
protected boolean	isThreadAccessAllowed(Thread thread, boolean singleThreaded) RegexLanguage is thread-safe - it supports parallel parsing requests as well as parallel access to all AbstractRegexObjects.
protected com.oracle.truffle.api.CallTarget	parse(com.oracle.truffle.api.TruffleLanguage.ParsingRequest parsingRequest)
protected boolean	patchContext(RegexLanguage.RegexContext context, com.oracle.truffle.api.TruffleLanguage.Env newEnv)

Methods inherited from class com.oracle.truffle.api.TruffleLanguage

areOptionsCompatible, disposeContext, disposeThread, exitContext, finalizeContext, finalizeThread, getAsynchronousStackDepth, getLanguageHome, getLanguageView, getOptionDescriptors, initializeContext, initializeMultipleContexts, initializeMultiThreading, initializeThread, isVisible, parse

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NAME

public static final String NAME

See Also:

Constant Field Values

ID

public static final String ID

See Also:

Constant Field Values

MIME_TYPE

public static final String MIME_TYPE

See Also:

Constant Field Values

parserGlobals

public final RegexParserGlobals parserGlobals

Constructor Detail

RegexLanguage

public RegexLanguage()

Method Detail

getCachedGroupBoundaries

public GroupBoundaries[] getCachedGroupBoundaries()

parse

protected com.oracle.truffle.api.CallTarget parse(com.oracle.truffle.api.TruffleLanguage.ParsingRequest parsingRequest)

Overrides:

parse in class com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

createContext

protected RegexLanguage.RegexContext createContext(com.oracle.truffle.api.TruffleLanguage.Env env)

Specified by:

createContext in class com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

patchContext

protected boolean patchContext(RegexLanguage.RegexContext context,
                               com.oracle.truffle.api.TruffleLanguage.Env newEnv)

Overrides:

patchContext in class com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

getScope

protected Object getScope(RegexLanguage.RegexContext context)

Overrides:

getScope in class com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

isThreadAccessAllowed

protected boolean isThreadAccessAllowed(Thread thread,
                                        boolean singleThreaded)

RegexLanguage is thread-safe - it supports parallel parsing requests as well as parallel access to all AbstractRegexObjects. Parallel access to RegexResults objects may lead to duplicate execution of code, but no wrong results.

Overrides:

isThreadAccessAllowed in class com.oracle.truffle.api.TruffleLanguage<RegexLanguage.RegexContext>

Parameters:

thread - the thread that accesses the context for the first time.

singleThreaded - true if the access is considered single-threaded, false if more than one thread is active at the same time.

Returns:

always true