Typedefs
typedef TValueOrError< TArray< FExpressionToken >, FExpressionError >	LexResultType

typedef TValueOrError< TArray< FCompiledToken >, FExpressionError >	CompileResultType

Functions
const FDecimalNumberFormattingRules &	GetLocalizedNumberFormattingRules ()

TOptional< FStringToken >	ParseNumberWithFallback (const FTokenStream &InStream, const FDecimalNumberFormattingRules &InPrimaryFormattingRules, const FDecimalNumberFormattingRules &InFallbackFormattingRules, FStringToken Accumulate=nullptr, double OutValue=nullptr)

TOptional< FStringToken >	ParseNumberWithRules (const FTokenStream &InStream, const FDecimalNumberFormattingRules &InFormattingRules, FStringToken Accumulate=nullptr, double OutValue=nullptr)

TOptional< FStringToken >	ParseLocalizedNumberWithAgnosticFallback (const FTokenStream &InStream, FStringToken Accumulate=nullptr, double OutValue=nullptr)

TOptional< FStringToken >	ParseLocalizedNumber (const FTokenStream &InStream, FStringToken Accumulate=nullptr, double OutValue=nullptr)

TOptional< FStringToken >	ParseNumber (const FTokenStream &InStream, FStringToken Accumulate=nullptr, double OutValue=nullptr)

TOptional< FExpressionError >	ConsumeNumberWithRules (FExpressionTokenConsumer &Consumer, const FDecimalNumberFormattingRules &InFormattingRules)

TOptional< FExpressionError >	ConsumeLocalizedNumberWithAgnosticFallback (FExpressionTokenConsumer &Consumer)

TOptional< FExpressionError >	ConsumeLocalizedNumber (FExpressionTokenConsumer &Consumer)

TOptional< FExpressionError >	ConsumeNumber (FExpressionTokenConsumer &Consumer)

template<typename TSymbol >
TOptional< FExpressionError >	ConsumeSymbol (FExpressionTokenConsumer &Consumer)

LexResultType	Lex (const TCHAR *InExpression, const FTokenDefinitions &TokenDefinitions)

CompileResultType	Compile (const TCHAR *InExpression, const FTokenDefinitions &TokenDefinitions, const FExpressionGrammar &InGrammar)

CompileResultType	Compile (TArray< FExpressionToken > InTokens, const FExpressionGrammar &InGrammar)

FExpressionResult	Evaluate (const TCHAR *InExpression, const FTokenDefinitions &InTokenDefinitions, const FExpressionGrammar &InGrammar, const IOperatorEvaluationEnvironment &InEnvironment)

FExpressionResult	Evaluate (const TArray< FCompiledToken > &CompiledTokens, const IOperatorEvaluationEnvironment &InEnvironment)

template<typename ContextType >
FExpressionResult	Evaluate (const TCHAR InExpression, const FTokenDefinitions &InTokenDefinitions, const FExpressionGrammar &InGrammar, const TOperatorJumpTable< ContextType > &InJumpTable, const ContextType InContext=nullptr)

template<typename ContextType >
FExpressionResult	Evaluate (const TArray< FCompiledToken > &CompiledTokens, const TOperatorJumpTable< ContextType > &InJumpTable, const ContextType *InContext=nullptr)

Detailed Description

Define some expression types for basic arithmetic

An expression parser, responsible for lexing, compiling, and evaluating expressions. The parser supports 3 functions:

Lexing the expression into a set of user defined tokens,
Compiling the tokenized expression to an efficient reverse-polish execution order,
Evaluating the compiled tokens

See ExpressionParserExamples.cpp for example usage.

Typedef Documentation

◆ CompileResultType

typedef TValueOrError< TArray<FCompiledToken>, FExpressionError > ExpressionParser::CompileResultType

Definition at line 23 of file ExpressionParser.h.

◆ LexResultType

typedef TValueOrError< TArray<FExpressionToken>, FExpressionError > ExpressionParser::LexResultType

Definition at line 22 of file ExpressionParser.h.

Function Documentation

◆ Compile() [1/2]

CompileResultType ExpressionParser::Compile	(	const TCHAR *	InExpression,
		const FTokenDefinitions &	TokenDefinitions,
		const FExpressionGrammar &	InGrammar )

Compile the specified expression into an array of Reverse-Polish order nodes for evaluation, according to our grammar definition

◆ Compile() [2/2]

CompileResultType ExpressionParser::Compile	(	TArray< FExpressionToken >	InTokens,
		const FExpressionGrammar &	InGrammar )

Compile the specified tokens into an array of Reverse-Polish order nodes for evaluation, according to our grammar definition

◆ ConsumeLocalizedNumber()

TOptional< FExpressionError > ExpressionParser::ConsumeLocalizedNumber ( FExpressionTokenConsumer & Consumer )

Consume a localized number from the specified consumer's stream, if one exists at the current read position

◆ ConsumeLocalizedNumberWithAgnosticFallback()

TOptional< FExpressionError > ExpressionParser::ConsumeLocalizedNumberWithAgnosticFallback ( FExpressionTokenConsumer & Consumer )

Consume a localized number from the specified consumer's stream, if one exists at the current read position

◆ ConsumeNumber()

TOptional< FExpressionError > ExpressionParser::ConsumeNumber ( FExpressionTokenConsumer & Consumer )

Consume a number from the specified consumer's stream, if one exists at the current read position

◆ ConsumeNumberWithRules()

TOptional< FExpressionError > ExpressionParser::ConsumeNumberWithRules	(	FExpressionTokenConsumer &	Consumer,
		const FDecimalNumberFormattingRules &	InFormattingRules )

Consume a number formatted using the given rules from the specified consumer's stream, if one exists at the current read position

◆ ConsumeSymbol()

template<typename TSymbol >

TOptional< FExpressionError > ExpressionParser::ConsumeSymbol ( FExpressionTokenConsumer & Consumer )

Consume a symbol from the specified consumer's stream, if one exists at the current read position

Definition at line 69 of file BasicMathExpressionEvaluator.h.

◆ Evaluate() [1/4]

FExpressionResult ExpressionParser::Evaluate	(	const TArray< FCompiledToken > &	CompiledTokens,
		const IOperatorEvaluationEnvironment &	InEnvironment )

Evaluate the specified pre-compiled tokens using an evaluation environment

◆ Evaluate() [2/4]

template<typename ContextType >

FExpressionResult ExpressionParser::Evaluate	(	const TArray< FCompiledToken > &	CompiledTokens,
		const TOperatorJumpTable< ContextType > &	InJumpTable,
		const ContextType *	InContext = nullptr )

Definition at line 49 of file ExpressionParser.h.

◆ Evaluate() [3/4]

FExpressionResult ExpressionParser::Evaluate	(	const TCHAR *	InExpression,
		const FTokenDefinitions &	InTokenDefinitions,
		const FExpressionGrammar &	InGrammar,
		const IOperatorEvaluationEnvironment &	InEnvironment )

Evaluate the specified expression using the specified token definitions, grammar definition, and evaluation environment

◆ Evaluate() [4/4]

template<typename ContextType >

FExpressionResult ExpressionParser::Evaluate	(	const TCHAR *	InExpression,
		const FTokenDefinitions &	InTokenDefinitions,
		const FExpressionGrammar &	InGrammar,
		const TOperatorJumpTable< ContextType > &	InJumpTable,
		const ContextType *	InContext = nullptr )

Templated versions of evaluation functions used when passing a specific jump table and context

Definition at line 42 of file ExpressionParser.h.

◆ GetLocalizedNumberFormattingRules()

const FDecimalNumberFormattingRules & ExpressionParser::GetLocalizedNumberFormattingRules ( )

Get the default set number formatting rules based on the current locale and user settings

◆ Lex()

LexResultType ExpressionParser::Lex	(	const TCHAR *	InExpression,
		const FTokenDefinitions &	TokenDefinitions )

Lex the specified string, using the specified grammar

◆ ParseLocalizedNumber()

TOptional< FStringToken > ExpressionParser::ParseLocalizedNumber	(	const FTokenStream &	InStream,
		FStringToken *	Accumulate = nullptr,
		double *	OutValue = nullptr )

Parse a localized number from the given stream, optionally from a specific read position

◆ ParseLocalizedNumberWithAgnosticFallback()

TOptional< FStringToken > ExpressionParser::ParseLocalizedNumberWithAgnosticFallback	(	const FTokenStream &	InStream,
		FStringToken *	Accumulate = nullptr,
		double *	OutValue = nullptr )