Package net.hydromatic.morel.ast

Class Core.Pat

java.lang.Object

net.hydromatic.morel.ast.AstNode

net.hydromatic.morel.ast.Core.BaseNode

net.hydromatic.morel.ast.Core.Pat

Direct Known Subclasses:

Core.Con0Pat, Core.ConPat, Core.ListPat, Core.LiteralPat, Core.NamedPat, Core.RecordPat, Core.TuplePat, Core.WildcardPat

Enclosing class:

Core

public abstract static class Core.Pat
extends Core.BaseNode

Base class for a pattern.

For example, "x" in "val x = 5" is a Core.IdPat; the "(x, y) in "val (x, y) = makePair 1 2" is a Core.TuplePat.

Field Summary

Fields

Modifier and Type	Field	Description
final Type	type

Fields inherited from class net.hydromatic.morel.ast.AstNode

op, pos

Constructor Summary

Constructors

Constructor	Description
Pat(Op op, Type type)

Method Summary

Modifier and Type	Method	Description
abstract Core.Pat	accept(Shuttle shuttle)	Accepts a shuttle, calling the Shuttle.visit(net.hydromatic.morel.ast.Ast.Literal) method appropriate to the type of this node, and returning the result.
String	describe(Describer describer)	Converts this pattern to a string.
Type	type()	Returns the type.

Methods inherited from class net.hydromatic.morel.ast.Core.BaseNode

accept

Methods inherited from class net.hydromatic.morel.ast.AstNode

toString, unparse, unparse

Methods inherited from class java.lang.Object

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

Field Details

type

public final Type type

Constructor Details

Pat

Pat(Op op,
 Type type)

Method Details

type

public Type type()

Returns the type.

accept

public abstract Core.Pat accept(Shuttle shuttle)

Description copied from class: AstNode

Accepts a shuttle, calling the Shuttle.visit(net.hydromatic.morel.ast.Ast.Literal) method appropriate to the type of this node, and returning the result.

Overrides:

accept in class Core.BaseNode

describe

public String describe(Describer describer)

Converts this pattern to a string.

The result is similar to that of AstNode.toString(), except that identifiers are permuted. For example, if a pattern includes "c.3" and "c.2" but not "c.0" or "c.1", then "c.3" will be printed as "c" and "c.2" will be printed as "c.1".

This behavior makes plans more concise if their local variables happen to have the same name as other variables that occur in functions in the session history.