com.espertech.esper.epl.parse

Class ParseHelper

java.lang.Object

com.espertech.esper.epl.parse.ParseHelper

public class ParseHelper
extends Object

Helper class for parsing an expression and walking a parse tree.

Field Summary

Fields

Modifier and Type	Field and Description
static String	NEWLINE Newline.

Constructor Summary

Constructors

Constructor and Description
ParseHelper()

Method Summary

Modifier and Type	Method and Description
static boolean	hasControlCharacters(String text)
static EsperEPL2GrammarLexer	newLexer(org.antlr.v4.runtime.CharStream input)
static EsperEPL2GrammarParser	newParser(org.antlr.v4.runtime.CommonTokenStream tokens)
static ParseResult	parse(String expression, String eplStatementErrorMsg, boolean addPleaseCheck, ParseRuleSelector parseRuleSelector, boolean rewriteScript) Parse expression using the rule the ParseRuleSelector instance supplies.
static void	walk(org.antlr.v4.runtime.tree.Tree ast, EPLTreeWalkerListener listener, String expression, String eplStatementForErrorMsg) Walk parse tree starting at the rule the walkRuleSelector supplies.

Methods inherited from class java.lang.Object

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

Field Detail

NEWLINE

public static final String NEWLINE

Newline.

Constructor Detail

ParseHelper

public ParseHelper()

Method Detail

walk

public static void walk(org.antlr.v4.runtime.tree.Tree ast,
                        EPLTreeWalkerListener listener,
                        String expression,
                        String eplStatementForErrorMsg)

Walk parse tree starting at the rule the walkRuleSelector supplies.

Parameters:

ast - - ast to walk

listener - - walker instance

expression - - the expression we are walking in string form

eplStatementForErrorMsg - - statement text for error messages

parse

public static ParseResult parse(String expression,
                                String eplStatementErrorMsg,
                                boolean addPleaseCheck,
                                ParseRuleSelector parseRuleSelector,
                                boolean rewriteScript)
                         throws EPException

Parse expression using the rule the ParseRuleSelector instance supplies.

Parameters:

expression - - text to parse

parseRuleSelector - - parse rule to select

addPleaseCheck - - true to include depth paraphrase

eplStatementErrorMsg - - text for error

rewriteScript - - whether to rewrite script expressions

Returns:

AST - syntax tree

Throws:

EPException - when the AST could not be parsed

newLexer

public static EsperEPL2GrammarLexer newLexer(org.antlr.v4.runtime.CharStream input)

newParser

public static EsperEPL2GrammarParser newParser(org.antlr.v4.runtime.CommonTokenStream tokens)

hasControlCharacters

public static boolean hasControlCharacters(String text)