org.mvel2.compiler
Class AbstractParser

java.lang.Object
  org.mvel2.compiler.AbstractParser

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

AbstractOptimizer, ExpressionCompiler, MacroProcessor, MVELInterpretedRuntime

public class AbstractParser
extends java.lang.Object
implements java.io.Serializable

This is the core parser that the subparsers extend.

Author:

Christopher Brock

See Also:

Serialized Form

Field Summary

protected java.lang.Object	ctx
protected int	cursor
protected boolean	debugSymbols
protected ExecutionStack	dStack
protected char[]	expr
protected int	fields
protected static int	GET
protected static int	GET_OR_CREATE
protected boolean	greedy
protected int	lastLineStart
protected ASTNode	lastNode
protected boolean	lastWasComment
protected boolean	lastWasIdentifier
protected boolean	lastWasLineLabel
protected int	length
static int	LEVEL_0_PROPERTY_ONLY
static int	LEVEL_1_BASIC_LANG
static int	LEVEL_2_MULTI_STATEMENT
static int	LEVEL_3_ITERATION
static int	LEVEL_4_ASSIGNMENT
static int	LEVEL_5_CONTROL_FLOW
protected int	line
protected boolean	literalOnly
static java.util.HashMap<java.lang.String,java.lang.Object>	LITERALS
protected static int	OP_CONTINUE
protected static int	OP_OVERFLOW
protected static int	OP_RESET_FRAME
protected static int	OP_TERMINATE
static java.util.HashMap<java.lang.String,java.lang.Integer>	OPERATORS
protected static java.lang.ThreadLocal<ParserContext>	parserContext
protected ParserContext	pCtx
protected static int	REMOVE
protected static int	SET
protected ExecutionStack	splitAccumulator
protected int	start
protected ExecutionStack	stk
protected VariableResolverFactory	variableFactory

Constructor Summary

AbstractParser()

Method Summary

protected void	addFatalError(java.lang.String message)
protected void	addFatalError(java.lang.String message, int row, int cols)
protected void	addWarning(java.lang.String message)
protected int	arithmeticFunctionReduction(int operator)
protected void	captureIdentifier()
protected void	captureToEOL() From the current cursor position, capture to the end of the line.
protected void	captureToEOS() Capture from the current cursor position, to the end of the statement.
protected void	captureToEOSorEOL() From the current cursor position, capture to the end of statement, or the end of line, whichever comes first.
protected void	captureToEOT() From the current cursor position, capture to the end of the current token.
protected void	captureToNextTokenJunction() From the current cursor position, capture to the end of the next token junction.
static ParserContext	contextControl(int operation, ParserContext pCtx, AbstractParser parser)
protected void	expectEOS()
void	expectNextChar_IW(char c)
protected static java.lang.String	getCurrentSourceFileName()
static ParserContext	getCurrentThreadParserContext()
protected ParserContext	getParserContext()
ASTNode	handleSubstatement(Substatement stmt)
protected ASTNode	handleUnion(ASTNode node)
protected boolean	ifThenElseBlockContinues() Checking from the current cursor position, check to see if the if-then-else block continues.
int	incNextNonBlank()
protected static boolean	isArithmeticOperator(int operator)
boolean	isDebugSymbols()
protected boolean	isNextIdentifier()
protected boolean	isNextIdentifierOrLiteral()
static boolean	isNotValidNameorLabel(java.lang.String name) Check if the specfied string represents a valid name of label.
static boolean	isReservedWord(java.lang.String name) Check if the specified string is a reserved word in the parser.
protected boolean	isStatementNotManuallyTerminated() NOTE: This method assumes that the current position of the cursor is at the end of a logical statement, to begin with.
protected boolean	lastNonWhite(char c)
static java.util.HashMap<java.lang.String,java.lang.Integer>	loadLanguageFeaturesByLevel(int languageLevel)
protected char	lookAhead() Return the next character (delta 1 of cursor position).
protected char	lookAhead(int range) Return the character, forward of the currrent cursor position based on the specified range delta.
protected char	lookBehind() Return the last character (delta -1 of cursor position).
protected char	lookToLast() Return the previous non-whitespace character.
void	newContext() Create a new ParserContext in the current thread.
void	newContext(ParserContext pCtx) Create a new ParserContext in the current thread, using the one specified.
int	nextNonBlank()
protected ASTNode	nextToken() Retrieve the next token in the expression.
protected ASTNode	nextTokenSkipSymbols()
protected void	reduce() This method is called when we reach the point where we must subEval a trinary operation in the expression.
void	removeContext() Remove the current ParserContext from the thread.
static void	resetParserContext() Remove the current parser context from the thread.
static void	setCurrentThreadParserContext(ParserContext pCtx)
void	setDebugSymbols(boolean debugSymbols)
protected void	setExpression(char[] expression)
protected void	setExpression(java.lang.String expression)
static void	setLanguageLevel(int level)
protected int	skipCommentBlock()
protected void	skipWhitespace() If the cursor is currently pointing to whitespace, move the cursor forward to the first non-whitespace character.
protected void	skipWhitespaceWithLineAccounting() If the cursor is currently pointing to whitespace, move the cursor forward to the first non-whitespace character, but account for carraige returns in the script (updates parser field: line).
protected boolean	tokenContinues() Checking from the current cursor position, check to see if we're inside a contiguous identifier.
protected int	trimLeft(int pos) From the specified cursor position, trim out any whitespace between the current position and the end of the last non-whitespace character.
protected int	trimRight(int pos) From the specified cursor position, trim out any whitespace between the current position and beginning of the first non-whitespace character.
protected void	trimWhitespace() From the current cursor position, trim backward over any whitespace to the first non-whitespace character.

Methods inherited from class java.lang.Object

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

Field Detail

expr

protected char[] expr

cursor

protected int cursor

start

protected int start

length

protected int length

fields

protected int fields

OP_OVERFLOW

protected static final int OP_OVERFLOW

See Also:

Constant Field Values

OP_TERMINATE

protected static final int OP_TERMINATE

See Also:

Constant Field Values

OP_RESET_FRAME

protected static final int OP_RESET_FRAME

See Also:

Constant Field Values

OP_CONTINUE

protected static final int OP_CONTINUE

See Also:

Constant Field Values

greedy

protected boolean greedy

lastWasIdentifier

protected boolean lastWasIdentifier

lastWasLineLabel

protected boolean lastWasLineLabel

lastWasComment

protected boolean lastWasComment

literalOnly

protected boolean literalOnly

debugSymbols

protected boolean debugSymbols

lastLineStart

protected int lastLineStart

line

protected int line

lastNode

protected ASTNode lastNode

LITERALS

public static final java.util.HashMap<java.lang.String,java.lang.Object> LITERALS

OPERATORS

public static final java.util.HashMap<java.lang.String,java.lang.Integer> OPERATORS

stk

protected ExecutionStack stk

splitAccumulator

protected ExecutionStack splitAccumulator

parserContext

protected static java.lang.ThreadLocal<ParserContext> parserContext

pCtx

protected ParserContext pCtx

dStack

protected ExecutionStack dStack

ctx

protected java.lang.Object ctx

variableFactory

protected VariableResolverFactory variableFactory

SET

protected static final int SET

See Also:

Constant Field Values

REMOVE

protected static final int REMOVE

See Also:

Constant Field Values

GET

protected static final int GET

See Also:

Constant Field Values

GET_OR_CREATE

protected static final int GET_OR_CREATE

See Also:

Constant Field Values

LEVEL_5_CONTROL_FLOW

public static final int LEVEL_5_CONTROL_FLOW

See Also:

Constant Field Values

LEVEL_4_ASSIGNMENT

public static final int LEVEL_4_ASSIGNMENT

See Also:

Constant Field Values

LEVEL_3_ITERATION

public static final int LEVEL_3_ITERATION

See Also:

Constant Field Values

LEVEL_2_MULTI_STATEMENT

public static final int LEVEL_2_MULTI_STATEMENT

See Also:

Constant Field Values

LEVEL_1_BASIC_LANG

public static final int LEVEL_1_BASIC_LANG

See Also:

Constant Field Values

LEVEL_0_PROPERTY_ONLY

public static final int LEVEL_0_PROPERTY_ONLY

See Also:

Constant Field Values

Constructor Detail

AbstractParser

public AbstractParser()

Method Detail

nextTokenSkipSymbols

protected ASTNode nextTokenSkipSymbols()

nextToken

protected ASTNode nextToken()

Retrieve the next token in the expression.

Returns:

-

handleSubstatement

public ASTNode handleSubstatement(Substatement stmt)

handleUnion

protected ASTNode handleUnion(ASTNode node)

ifThenElseBlockContinues

protected boolean ifThenElseBlockContinues()

Checking from the current cursor position, check to see if the if-then-else block continues.

Returns:

boolean value

skipCommentBlock

protected int skipCommentBlock()

tokenContinues

protected boolean tokenContinues()

Checking from the current cursor position, check to see if we're inside a contiguous identifier.

Returns:

-

expectEOS

protected void expectEOS()

isNextIdentifier

protected boolean isNextIdentifier()

captureToEOS

protected void captureToEOS()

Capture from the current cursor position, to the end of the statement.

captureToEOSorEOL

protected void captureToEOSorEOL()

From the current cursor position, capture to the end of statement, or the end of line, whichever comes first.

captureToEOL

protected void captureToEOL()

From the current cursor position, capture to the end of the line.

captureIdentifier

protected void captureIdentifier()

captureToEOT

protected void captureToEOT()

From the current cursor position, capture to the end of the current token.

lastNonWhite

protected boolean lastNonWhite(char c)

trimLeft

protected int trimLeft(int pos)

From the specified cursor position, trim out any whitespace between the current position and the end of the last non-whitespace character.

Parameters:

pos - - current position

Returns:

new position.

trimRight

protected int trimRight(int pos)

From the specified cursor position, trim out any whitespace between the current position and beginning of the first non-whitespace character.

Parameters:

pos - -

Returns:

-

skipWhitespace

protected void skipWhitespace()

If the cursor is currently pointing to whitespace, move the cursor forward to the first non-whitespace character.

skipWhitespaceWithLineAccounting

protected void skipWhitespaceWithLineAccounting()

If the cursor is currently pointing to whitespace, move the cursor forward to the first non-whitespace character, but account for carraige returns in the script (updates parser field: line).

captureToNextTokenJunction

protected void captureToNextTokenJunction()

From the current cursor position, capture to the end of the next token junction.

trimWhitespace

protected void trimWhitespace()

From the current cursor position, trim backward over any whitespace to the first non-whitespace character.

isReservedWord

public static boolean isReservedWord(java.lang.String name)

Check if the specified string is a reserved word in the parser.

Parameters:

name -

Returns:

isNotValidNameorLabel

public static boolean isNotValidNameorLabel(java.lang.String name)

Check if the specfied string represents a valid name of label.

Parameters:

name -

Returns:

setExpression

protected void setExpression(java.lang.String expression)

setExpression

protected void setExpression(char[] expression)

lookToLast

protected char lookToLast()

Return the previous non-whitespace character.

Returns:

lookBehind

protected char lookBehind()

Return the last character (delta -1 of cursor position).

Returns:

lookAhead

protected char lookAhead()

Return the next character (delta 1 of cursor position).

Returns:

lookAhead

protected char lookAhead(int range)

Return the character, forward of the currrent cursor position based on the specified range delta.

Parameters:

range -

Returns:

isNextIdentifierOrLiteral

protected boolean isNextIdentifierOrLiteral()

incNextNonBlank

public int incNextNonBlank()

nextNonBlank

public int nextNonBlank()

expectNextChar_IW

public void expectNextChar_IW(char c)

isStatementNotManuallyTerminated

protected boolean isStatementNotManuallyTerminated()

NOTE: This method assumes that the current position of the cursor is at the end of a logical statement, to begin with.

Determines whether or not the logical statement is manually terminated with a statement separator (';').

Returns:

getParserContext

protected ParserContext getParserContext()

getCurrentThreadParserContext

public static ParserContext getCurrentThreadParserContext()

setCurrentThreadParserContext

public static void setCurrentThreadParserContext(ParserContext pCtx)

newContext

public void newContext()

Create a new ParserContext in the current thread.

newContext

public void newContext(ParserContext pCtx)

Create a new ParserContext in the current thread, using the one specified.

Parameters:

pCtx -

removeContext

public void removeContext()

Remove the current ParserContext from the thread.

contextControl

public static ParserContext contextControl(int operation,
                                           ParserContext pCtx,
                                           AbstractParser parser)

isDebugSymbols

public boolean isDebugSymbols()

setDebugSymbols

public void setDebugSymbols(boolean debugSymbols)

getCurrentSourceFileName

protected static java.lang.String getCurrentSourceFileName()

addFatalError

protected void addFatalError(java.lang.String message)

addFatalError

protected void addFatalError(java.lang.String message,
                             int row,
                             int cols)

addWarning

protected void addWarning(java.lang.String message)

setLanguageLevel

public static void setLanguageLevel(int level)

loadLanguageFeaturesByLevel

public static java.util.HashMap<java.lang.String,java.lang.Integer> loadLanguageFeaturesByLevel(int languageLevel)

resetParserContext

public static void resetParserContext()

Remove the current parser context from the thread.

isArithmeticOperator

protected static boolean isArithmeticOperator(int operator)

arithmeticFunctionReduction

protected int arithmeticFunctionReduction(int operator)

reduce

protected void reduce()

This method is called when we reach the point where we must subEval a trinary operation in the expression. (ie. val1 op val2). This is not the same as a binary operation, although binary operations would appear to have 3 structures as well. A binary structure (or also a junction in the expression) compares the current state against 2 downrange structures (usually an op and a val).