org.apache.velocity.runtime.parser
Class Parser

java.lang.Object
  org.apache.velocity.runtime.parser.Parser

All Implemented Interfaces:

ParserConstants, ParserTreeConstants

public class Parser
extends Object
implements ParserTreeConstants, ParserConstants

This class is responsible for parsing a Velocity template. This class was generated by JavaCC using the JJTree extension to produce an Abstract Syntax Tree (AST) of the template. Please look at the Parser.jjt file which is what controls the generation of this class.

Version:

$Id: Parser.java 463419 2006-10-12 20:39:49Z henning $

Author:

Jason van Zyl, Geir Magnusson Jr., Henning P. Schmiedehausen

Field Summary

Token	jj_nt
protected org.apache.velocity.runtime.parser.JJTParserState	jjtree
boolean	lookingAhead
Token	token
ParserTokenManager	token_source

Fields inherited from interface org.apache.velocity.runtime.parser.ParserTreeConstants

JJTADDNODE, JJTANDNODE, JJTASSIGNMENT, JJTBLOCK, JJTCOMMENT, JJTDIRECTIVE, JJTDIVNODE, JJTELSEIFSTATEMENT, JJTELSESTATEMENT, JJTEQNODE, JJTESCAPE, JJTESCAPEDDIRECTIVE, JJTEXPRESSION, JJTFALSE, JJTFLOATINGPOINTLITERAL, JJTGENODE, JJTGTNODE, JJTIDENTIFIER, JJTIFSTATEMENT, JJTINTEGERLITERAL, JJTINTEGERRANGE, JJTLENODE, JJTLTNODE, JJTMAP, JJTMETHOD, JJTMODNODE, JJTMULNODE, JJTNENODE, jjtNodeName, JJTNOTNODE, JJTOBJECTARRAY, JJTORNODE, JJTPROCESS, JJTREFERENCE, JJTSETDIRECTIVE, JJTSTOP, JJTSTRINGLITERAL, JJTSUBTRACTNODE, JJTTEXT, JJTTRUE, JJTVOID, JJTWORD

Fields inherited from interface org.apache.velocity.runtime.parser.ParserConstants

ALPHA_CHAR, ALPHANUM_CHAR, BRACKETED_WORD, COLON, COMMA, DEFAULT, DIGIT, DIRECTIVE, DIRECTIVE_CHAR, DIRECTIVE_TERMINATOR, DIVIDE, DOLLAR, DOLLARBANG, DOT, DOUBLE_ESCAPE, DOUBLEDOT, ELSE_DIRECTIVE, ELSEIF_DIRECTIVE, END, EOF, EQUALS, ESCAPE, ESCAPE_DIRECTIVE, EXPONENT, FALSE, FLOATING_POINT_LITERAL, FORMAL_COMMENT, HASH, IDENTIFIER, IDENTIFIER_CHAR, IF_DIRECTIVE, IN_FORMAL_COMMENT, IN_MULTI_LINE_COMMENT, IN_SINGLE_LINE_COMMENT, INTEGER_LITERAL, LBRACKET, LCURLY, LEFT_CURLEY, LETTER, LOGICAL_AND, LOGICAL_EQUALS, LOGICAL_GE, LOGICAL_GT, LOGICAL_LE, LOGICAL_LT, LOGICAL_NOT, LOGICAL_NOT_EQUALS, LOGICAL_OR, LPAREN, MINUS, MODULUS, MULTI_LINE_COMMENT, MULTIPLY, NEWLINE, PLUS, PRE_DIRECTIVE, RBRACKET, RCURLY, REFERENCE, REFERENCE_TERMINATOR, REFMOD2, REFMOD2_RPAREN, REFMODIFIER, RIGHT_CURLEY, RPAREN, SET_DIRECTIVE, SINGLE_LINE_COMMENT, SINGLE_LINE_COMMENT_START, STOP_DIRECTIVE, STRING_LITERAL, TEXT, tokenImage, TRUE, WHITESPACE, WORD

Constructor Summary

Parser(CharStream stream)

Parser(ParserTokenManager tm)

Parser(RuntimeServices rs)
This constructor was added to allow the re-use of parsers.

Method Summary

void	AdditiveExpression()
void	Assignment()
void	Comment()
void	ConditionalAndExpression()
void	ConditionalOrExpression()
SimpleNode	Directive() Supports the Pluggable Directives #foo( arg+ )
int	DirectiveArg() Supports the arguments for the Pluggable Directives
void	disable_tracing()
void	ElseIfStatement()
void	ElseStatement()
void	enable_tracing()
void	EqualityExpression()
void	Escape() Used to catch and process escape sequences in grammatical constructs as escapes outside of VTL are just characters.
void	EscapedDirective() used to separate the notion of a valid directive that has been escaped, versus something that looks like a directive and is just schmoo.
void	Expression()
void	False()
void	FloatingPointLiteral()
ParseException	generateParseException()
Directive	getDirective(String directive) This method gets a Directive from the directives Hashtable
Token	getNextToken()
Token	getToken(int index)
void	Identifier() This method corresponds to variable references in Velocity templates.
void	IfStatement()
void	IntegerLiteral()
void	IntegerRange() supports the [n..m] vector generator for use in the #foreach() to generate measured ranges w/o needing explicit support from the app/servlet
boolean	isDirective(String directive) This method finds out of the directive exists in the directives Hashtable.
void	Map() for creating a map in a #set #set($foo = {$foo : $bar, $blargh : $thingy})
void	Method() This method has yet to be fully implemented but will allow arbitrarily nested method calls
void	MultiplicativeExpression()
void	ObjectArray()
void	Parameter() This method has yet to be fully implemented but will allow arbitrarily nested method calls
SimpleNode	parse(Reader reader, String templateName) This was also added to allow parsers to be re-usable.
void	PrimaryExpression()
SimpleNode	process() This method is what starts the whole parsing process.
void	Reference()
void	ReInit(CharStream stream)
void	ReInit(ParserTokenManager tm)
void	RelationalExpression()
void	SetDirective() Currently support both types of set : #set( expr ) #set expr
void	setDirectives(Hashtable directives) This method sets the directives Hashtable
void	Statement() These are the types of statements that are acceptable in Velocity templates.
void	StopStatement() This method corresponds to the #stop directive which just simulates and EOF so that parsing stops.
void	StringLiteral()
void	Text() This method is responsible for allowing all non-grammar text to pass through unscathed.
void	True()
void	UnaryExpression()
void	Word()

Methods inherited from class java.lang.Object

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

Field Detail

jjtree

protected org.apache.velocity.runtime.parser.JJTParserState jjtree

token_source

public ParserTokenManager token_source

token

public Token token

jj_nt

public Token jj_nt

lookingAhead

public boolean lookingAhead

Constructor Detail

Parser

public Parser(RuntimeServices rs)

This constructor was added to allow the re-use of parsers. The normal constructor takes a single argument which an InputStream. This simply creates a re-usable parser object, we satisfy the requirement of an InputStream by using a newline character as an input stream.

Parser

public Parser(CharStream stream)

Parser

public Parser(ParserTokenManager tm)

Method Detail

parse

public SimpleNode parse(Reader reader,
                        String templateName)
                 throws ParseException

This was also added to allow parsers to be re-usable. Normal JavaCC use entails passing an input stream to the constructor and the parsing process is carried out once. We want to be able to re-use parsers: we do this by adding this method and re-initializing the lexer with the new stream that we want parsed.

Throws:

ParseException

setDirectives

public void setDirectives(Hashtable directives)

This method sets the directives Hashtable

getDirective

public Directive getDirective(String directive)

This method gets a Directive from the directives Hashtable

isDirective

public boolean isDirective(String directive)

This method finds out of the directive exists in the directives Hashtable.

process

public final SimpleNode process()
                         throws ParseException

This method is what starts the whole parsing process. After the parsing is complete and the template has been turned into an AST, this method returns the root of AST which can subsequently be traversed by a visitor which implements the ParserVisitor interface which is generated automatically by JavaCC

Throws:

ParseException

Statement

public final void Statement()
                     throws ParseException

These are the types of statements that are acceptable in Velocity templates.

Throws:

ParseException

EscapedDirective

public final void EscapedDirective()
                            throws ParseException

used to separate the notion of a valid directive that has been escaped, versus something that looks like a directive and is just schmoo. This is important to do as a separate production that creates a node, because we want this, in either case, to stop the further parsing of the Directive() tree.

Throws:

ParseException

Escape

public final void Escape()
                  throws ParseException

Used to catch and process escape sequences in grammatical constructs as escapes outside of VTL are just characters. Right now we have both this and the EscapeDirective() construction because in the EscapeDirective() case, we want to suck in the # and here we don't. We just want the escapes to render correctly

Throws:

ParseException

Comment

public final void Comment()
                   throws ParseException

Throws:

ParseException

FloatingPointLiteral

public final void FloatingPointLiteral()
                                throws ParseException

Throws:

ParseException

IntegerLiteral

public final void IntegerLiteral()
                          throws ParseException

Throws:

ParseException

StringLiteral

public final void StringLiteral()
                         throws ParseException

Throws:

ParseException

Identifier

public final void Identifier()
                      throws ParseException

This method corresponds to variable references in Velocity templates. The following are examples of variable references that may be found in a template: $foo $bar

Throws:

ParseException

Word

public final void Word()
                throws ParseException

Throws:

ParseException

DirectiveArg

public final int DirectiveArg()
                       throws ParseException

Supports the arguments for the Pluggable Directives

Throws:

ParseException

Directive

public final SimpleNode Directive()
                           throws ParseException

Supports the Pluggable Directives #foo( arg+ )

Throws:

ParseException

Map

public final void Map()
               throws ParseException

for creating a map in a #set #set($foo = {$foo : $bar, $blargh : $thingy})

Throws:

ParseException

ObjectArray

public final void ObjectArray()
                       throws ParseException

Throws:

ParseException

IntegerRange

public final void IntegerRange()
                        throws ParseException

supports the [n..m] vector generator for use in the #foreach() to generate measured ranges w/o needing explicit support from the app/servlet

Throws:

ParseException

Parameter

public final void Parameter()
                     throws ParseException

This method has yet to be fully implemented but will allow arbitrarily nested method calls

Throws:

ParseException

Method

public final void Method()
                  throws ParseException

This method has yet to be fully implemented but will allow arbitrarily nested method calls

Throws:

ParseException

Reference

public final void Reference()
                     throws ParseException

Throws:

ParseException

True

public final void True()
                throws ParseException

Throws:

ParseException

False

public final void False()
                 throws ParseException

Throws:

ParseException

Text

public final void Text()
                throws ParseException

This method is responsible for allowing all non-grammar text to pass through unscathed.

Throws:

ParseException

IfStatement

public final void IfStatement()
                       throws ParseException

Throws:

ParseException

ElseStatement

public final void ElseStatement()
                         throws ParseException

Throws:

ParseException

ElseIfStatement

public final void ElseIfStatement()
                           throws ParseException

Throws:

ParseException

SetDirective

public final void SetDirective()
                        throws ParseException

Currently support both types of set : #set( expr ) #set expr

Throws:

ParseException

StopStatement

public final void StopStatement()
                         throws ParseException

This method corresponds to the #stop directive which just simulates and EOF so that parsing stops. The #stop directive is useful for end-user debugging purposes.

Throws:

ParseException

Expression

public final void Expression()
                      throws ParseException

Throws:

ParseException

Assignment

public final void Assignment()
                      throws ParseException

Throws:

ParseException

ConditionalOrExpression

public final void ConditionalOrExpression()
                                   throws ParseException

Throws:

ParseException

ConditionalAndExpression

public final void ConditionalAndExpression()
                                    throws ParseException

Throws:

ParseException

EqualityExpression

public final void EqualityExpression()
                              throws ParseException

Throws:

ParseException

RelationalExpression

public final void RelationalExpression()
                                throws ParseException

Throws:

ParseException

AdditiveExpression

public final void AdditiveExpression()
                              throws ParseException

Throws:

ParseException

MultiplicativeExpression

public final void MultiplicativeExpression()
                                    throws ParseException

Throws:

ParseException

UnaryExpression

public final void UnaryExpression()
                           throws ParseException

Throws:

ParseException

PrimaryExpression

public final void PrimaryExpression()
                             throws ParseException

Throws:

ParseException

ReInit

public void ReInit(CharStream stream)

ReInit

public void ReInit(ParserTokenManager tm)

getNextToken

public final Token getNextToken()

getToken

public final Token getToken(int index)

generateParseException

public ParseException generateParseException()

enable_tracing

public final void enable_tracing()

disable_tracing

public final void disable_tracing()