Class OperatorTable<T>

java.lang.Object

com.google.common.labs.parse.OperatorTable<T>

public final class OperatorTable<T>
extends Object

Provides a fluent API for building an operator precedence grammar.

For example, to build a simple calculator parser, you can implement it as:

 Parser<Integer> calculator = new OperatorTable<Integer>()
     .leftAssociative("+", (l, r) -> l + r, 10)
     .leftAssociative("-", (l, r) -> l - r, 10)
     .leftAssociative("*", (l, r) -> l * r), 20)
     .rightAssociative("^", (l, r) -> pow(l, r), 30)
     .prefix("-", n -> -n, 40)
     .postfix("++", n -> n + 1, 40)
     .postfix("--", n -> n - 1, 40)
     .build(consecutive(DIGIT, "number").map(Integer::parseInt));

 calculator.parse("1+2*3^2") // 19
 calculator.parseSkipping(whitespace(), "1 + 2") // 3
 

Constructor Summary

Constructors

Constructor	Description
OperatorTable()

Method Summary

Modifier and Type	Method	Description
Parser<T>	build(Parser<? extends T> operand)	Builds a parser with the configured operators applied to the given operand.
OperatorTable<T>	leftAssociative(Parser<? extends BinaryOperator<T>> operator, int precedence)	Adds a left-associative infix operator with the given precedence to the table.
OperatorTable<T>	leftAssociative(String op, BinaryOperator<T> operator, int precedence)	Adds a left-associative infix operator with the given precedence to the table.
OperatorTable<T>	nonAssociative(Parser<? extends BinaryOperator<T>> operator, int precedence)	Adds a non-associative infix operator (e.g.
OperatorTable<T>	nonAssociative(String op, BinaryOperator<T> operator, int precedence)	Adds a non-associative infix operator (e.g.
OperatorTable<T>	postfix(Parser<? extends UnaryOperator<T>> operator, int precedence)	Adds a postfix operator with the given precedence to the table.
<S> OperatorTable<T>	postfix(Parser<S> operator, BiFunction<? super T, ? super S, ? extends T> postfixFunction, int precedence)	Adds a postfix operator with the given precedence to the table.
OperatorTable<T>	postfix(String op, UnaryOperator<T> operator, int precedence)	Adds a postfix operator with the given precedence to the table.
OperatorTable<T>	prefix(Parser<? extends UnaryOperator<T>> operator, int precedence)	Adds a prefix operator with the given precedence to the table.
OperatorTable<T>	prefix(String op, UnaryOperator<T> operator, int precedence)	Adds a prefix operator with the given precedence to the table.
OperatorTable<T>	rightAssociative(Parser<? extends BinaryOperator<T>> operator, int precedence)	Adds a right-associative infix operator with the given precedence to the table.
OperatorTable<T>	rightAssociative(String op, BinaryOperator<T> operator, int precedence)	Adds a right-associative infix operator with the given precedence to the table.

Methods inherited from class java.lang.Object

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

Constructor Details

OperatorTable

public OperatorTable()

Method Details

prefix

@CanIgnoreReturnValue
public OperatorTable<T> prefix(String op,
 UnaryOperator<T> operator,
 int precedence)

Adds a prefix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

prefix

@CanIgnoreReturnValue
public OperatorTable<T> prefix(Parser<? extends UnaryOperator<T>> operator,
 int precedence)

Adds a prefix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

postfix

@CanIgnoreReturnValue
public OperatorTable<T> postfix(String op,
 UnaryOperator<T> operator,
 int precedence)

Adds a postfix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

postfix

@CanIgnoreReturnValue
public <S> OperatorTable<T> postfix(Parser<S> operator,
 BiFunction<? super T, ? super S, ? extends T> postfixFunction,
 int precedence)

Adds a postfix operator with the given precedence to the table. This binary operator will call postfixFunction.apply(operand, postfixValue), where postfixValue is the result of the postfix operator parser. The higher precedence value the higher precedence it is.

Since:

9.5

postfix

@CanIgnoreReturnValue
public OperatorTable<T> postfix(Parser<? extends UnaryOperator<T>> operator,
 int precedence)

Adds a postfix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

leftAssociative

@CanIgnoreReturnValue
public OperatorTable<T> leftAssociative(String op,
 BinaryOperator<T> operator,
 int precedence)

Adds a left-associative infix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

leftAssociative

@CanIgnoreReturnValue
public OperatorTable<T> leftAssociative(Parser<? extends BinaryOperator<T>> operator,
 int precedence)

Adds a left-associative infix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

nonAssociative

@CanIgnoreReturnValue
public OperatorTable<T> nonAssociative(String op,
 BinaryOperator<T> operator,
 int precedence)

Adds a non-associative infix operator (e.g. a comparison operator like '>'), with the given precedence to the table. The higher precedence value the higher precedence it is.

nonAssociative

@CanIgnoreReturnValue
public OperatorTable<T> nonAssociative(Parser<? extends BinaryOperator<T>> operator,
 int precedence)

Adds a non-associative infix operator (e.g. a comparison operator like '>'), with the given precedence to the table. The higher precedence value the higher precedence it is.

rightAssociative

@CanIgnoreReturnValue
public OperatorTable<T> rightAssociative(String op,
 BinaryOperator<T> operator,
 int precedence)

Adds a right-associative infix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

rightAssociative

@CanIgnoreReturnValue
public OperatorTable<T> rightAssociative(Parser<? extends BinaryOperator<T>> operator,
 int precedence)

Adds a right-associative infix operator with the given precedence to the table. The higher precedence value the higher precedence it is.

build

public Parser<T> build(Parser<? extends T> operand)

Builds a parser with the configured operators applied to the given operand.