Package io.pebbletemplates.pebble.parser

Class ExpressionParser

java.lang.Object

io.pebbletemplates.pebble.parser.ExpressionParser

public class ExpressionParser
extends Object

Parses expressions.

Field Summary

Fields

Modifier and Type	Field	Description
private Map<String,BinaryOperator>	binaryOperators
private final Parser	parser
private ParserOptions	parserOptions
private static final Set<String>	RESERVED_KEYWORDS
private TokenStream	stream
private Map<String,UnaryOperator>	unaryOperators

Constructor Summary

Constructors

Constructor	Description
ExpressionParser(Parser parser, Map<String,BinaryOperator> binaryOperators, Map<String,UnaryOperator> unaryOperators, ParserOptions parserOptions)	Constructor

Method Summary

Modifier and Type	Method	Description
private boolean	isBinary(Token token)	Checks if a token is a binary operator.
private boolean	isUnary(Token token)	Checks if a token is a unary operator.
private ArgumentsNode	parseArguments()
ArgumentsNode	parseArguments(boolean isMacroDefinition)
private Expression<?>	parseArrayDefinitionExpression()
private Expression<?>	parseBeanAttributeExpression(Expression<?> node)	A bean attribute expression can either be an expression getting an attribute from a variable in the context, or calling a method from a variable.
Expression<?>	parseExpression()	The public entry point for parsing an expression.
private Expression<?>	parseExpression(int minPrecedence)	A private entry point for parsing an expression.
FilterInvocationExpression	parseFilterInvocationExpression()
private Expression<?>	parseFunctionOrMacroInvocation(Expression<?> node)
private Expression<?>	parseMapDefinitionExpression()
String	parseNewVariableName()	Parses a new variable that will need to be initialized in the Java code.
private Expression<?>	parsePostfixExpression(Expression<?> node)	Determines if there is more to the provided expression than we originally thought.
private Expression<?>	parseStringExpression()
private Expression<?>	parseTernaryExpression(Expression<?> expression)
private Expression<?>	parseTestInvocationExpression()
private Expression<?>	subparseExpression()	Finds and returns the next "simple" expression; an expression of which can be found on either side of a binary operator but does not contain a binary operator.

Methods inherited from class java.lang.Object

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

Field Details

RESERVED_KEYWORDS

private static final Set<String> RESERVED_KEYWORDS

parser

private final Parser parser

stream

private TokenStream stream

binaryOperators

private Map<String,BinaryOperator> binaryOperators

unaryOperators

private Map<String,UnaryOperator> unaryOperators

parserOptions

private ParserOptions parserOptions

Constructor Details

ExpressionParser

public ExpressionParser(Parser parser,
 Map<String,BinaryOperator> binaryOperators,
 Map<String,UnaryOperator> unaryOperators,
 ParserOptions parserOptions)

Constructor

Parameters:

parser - A reference to the main parser

binaryOperators - All the binary operators

unaryOperators - All the unary operators

Method Details

parseExpression

public Expression<?> parseExpression()

The public entry point for parsing an expression.

Returns:

NodeExpression the expression that has been parsed.

parseExpression

private Expression<?> parseExpression(int minPrecedence)

A private entry point for parsing an expression. This method takes in the precedence required to operate a "precedence climbing" parsing algorithm. It is a recursive method.

Returns:

The NodeExpression representing the parsed expression.

See Also:

• "http://en.wikipedia.org/wiki/Operator-precedence_parser"

isUnary

private boolean isUnary(Token token)

Checks if a token is a unary operator.

Parameters:

token - The token that we are checking

Returns:

boolean Whether the token is a unary operator or not

isBinary

private boolean isBinary(Token token)

Checks if a token is a binary operator.

Parameters:

token - The token that we are checking

Returns:

boolean Whether the token is a binary operator or not

subparseExpression

private Expression<?> subparseExpression()

Finds and returns the next "simple" expression; an expression of which can be found on either side of a binary operator but does not contain a binary operator. Ex. "var.field", "true", "12", etc.

Returns:

NodeExpression The expression that it found.

parseStringExpression

private Expression<?> parseStringExpression()
                                     throws ParserException

Throws:

ParserException

parseTernaryExpression

private Expression<?> parseTernaryExpression(Expression<?> expression)

parsePostfixExpression

private Expression<?> parsePostfixExpression(Expression<?> node)

Determines if there is more to the provided expression than we originally thought. We will look for the filter operator or perhaps we are getting an attribute from a variable (ex. var.attribute or var['attribute'] or var.attribute(bar)).

Parameters:

node - The expression that we have already discovered

Returns:

Either the original expression that was passed in or a slightly modified version of it, depending on what was discovered.

parseFunctionOrMacroInvocation

private Expression<?> parseFunctionOrMacroInvocation(Expression<?> node)

parseFilterInvocationExpression

public FilterInvocationExpression parseFilterInvocationExpression()

parseTestInvocationExpression

private Expression<?> parseTestInvocationExpression()

parseBeanAttributeExpression

private Expression<?> parseBeanAttributeExpression(Expression<?> node)

A bean attribute expression can either be an expression getting an attribute from a variable in the context, or calling a method from a variable. Ex. foo.bar or foo['bar'] or foo.bar('baz')

Parameters:

node - The expression parsed so far

Returns:

NodeExpression The parsed subscript expression

parseArguments

private ArgumentsNode parseArguments()

parseArguments

public ArgumentsNode parseArguments(boolean isMacroDefinition)

parseNewVariableName

public String parseNewVariableName()

Parses a new variable that will need to be initialized in the Java code. This is used for the set tag, the for loop, and in named arguments.

Returns:

A variable name

parseArrayDefinitionExpression

private Expression<?> parseArrayDefinitionExpression()

parseMapDefinitionExpression

private Expression<?> parseMapDefinitionExpression()