hlt.language.design.kernel

Class Abstraction

java.lang.Object

hlt.language.design.kernel.Expression

hlt.language.design.kernel.ProtoExpression

hlt.language.design.kernel.Scope

hlt.language.design.kernel.Abstraction

All Implemented Interfaces:

Locatable

public class Abstraction
extends Scope

This class represents λ-calculus abstractions. More precisely, it represents multiple-parameter abstractions. This enables application to multiple arguments without having to "curry" it into a composition of single-parameter abstractions. This class extends Scope with the added mechanism needed to encapsulate lexically closed variables.

Field Summary

Fields inherited from class hlt.language.design.kernel.Expression

VOID_ASSIGNMENTS

Constructor Summary

Constructors

Constructor and Description
Abstraction(java.util.AbstractList parameters, Expression body)
Abstraction(Expression body)
Abstraction(Parameter[] parameters, Expression body) Creates a new Abstraction instance.
Abstraction(Parameter parameter, Expression body)
Abstraction(java.lang.String name, Expression body)

Method Summary

Methods

Modifier and Type	Method and Description
void	addToFrame(Local local)
Expression	copy() Returns a deep copy of this expression.
boolean	isExitable()
void	sanitizeSorts(Enclosure enclosure) This method walks down the expression gathering information relating each Local object to the Scope containing the corresponding Parameter in its array of formal parameters.
Scope	setIsExitable(boolean flag)
Scope	setNonExitable()
Expression	shiftOffsets(int intShift, int realShift, int objectShift, int intDepth, int realDepth, int objectDepth) This methods visits this expression shifting the offset of all the Locals it encounters by the specified amount (per sort) as long as the offset it sees is referencing a parameter within the specified scope depth (per sort); This method is used when the compiler needs to synthesize an scope from an already typechecked expression (i.e., for currying or un/boxing - e.g., see the pad method below).
java.lang.String	toString()
void	typeCheck(TypeChecker typeChecker) This method type-checks this expression in the context of the specified TypeChecker.
Expression	typedCopy() Returns a deep copy of this expression this and all its subexpressions share the same type as their copy's counterparts.

Methods inherited from class hlt.language.design.kernel.Scope

arity, body, compile, containsFreeName, enclosingScope, intArity, numberOfSubexpressions, objectArity, parameter, parameters, realArity, sanitizeNames, setBody, setCheckedType, setCheckedType, setSortedArities, setSubexpression, subexpression, substitute, voidArity

Methods inherited from class hlt.language.design.kernel.ProtoExpression

checkedType, setType, type, typeRef

Methods inherited from class hlt.language.design.kernel.Expression

addType, addTypes, boxSort, extent, getEnd, getStart, isConstant, isEquality, isFalse, isHiddenSlicing, isNull, isSelector, isSlicing, isTrue, isVoid, locationString, otherTypes, setCheckedTypeLocked, setEnd, setExtent, setOtherTypes, setStart, shiftOffsets, sort, typeCheck, typeCheck, typeCheckLocked

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Abstraction

public Abstraction(Parameter[] parameters,
           Expression body)

Creates a new Abstraction instance.

Parameters:

parameters - a Parameter[] value

body - an Expression value

Abstraction

public Abstraction(Parameter parameter,
           Expression body)

Abstraction

public Abstraction(java.lang.String name,
           Expression body)

Abstraction

public Abstraction(Expression body)

Abstraction

public Abstraction(java.util.AbstractList parameters,
           Expression body)

Method Detail

copy

public final Expression copy()

Description copied from class: Expression

Returns a deep copy of this expression. The types are not not copied. NB: This is a convenience for building expressions that should be used exclusively before any processing (in particular sanitizing), is done on this expression.

Overrides:

copy in class Scope

typedCopy

public final Expression typedCopy()

Description copied from class: Expression

Returns a deep copy of this expression this and all its subexpressions share the same type as their copy's counterparts. NB: This is a convenience for building expressions that should be used exclusively before any processing (in particular sanitizing), is done on this expression.

Overrides:

typedCopy in class Scope

isExitable

public final boolean isExitable()

setIsExitable

public final Scope setIsExitable(boolean flag)

setNonExitable

public final Scope setNonExitable()

addToFrame

public final void addToFrame(Local local)

sanitizeSorts

public final void sanitizeSorts(Enclosure enclosure)

Description copied from class: Expression

This method walks down the expression gathering information relating each Local object to the Scope containing the corresponding Parameter in its array of formal parameters. It takes as an argument an Enclosure, which is a Stack containing all Scopes encountered along the way, equipped with a method to compute all the information necessary in computing the local's offset.

Overrides:

sanitizeSorts in class Scope

shiftOffsets

public final Expression shiftOffsets(int intShift,
                      int realShift,
                      int objectShift,
                      int intDepth,
                      int realDepth,
                      int objectDepth)

Description copied from class: Expression

This methods visits this expression shifting the offset of all the Locals it encounters by the specified amount (per sort) as long as the offset it sees is referencing a parameter within the specified scope depth (per sort); This method is used when the compiler needs to synthesize an scope from an already typechecked expression (i.e., for currying or un/boxing - e.g., see the pad method below).

Overrides:

shiftOffsets in class Scope

typeCheck

public final void typeCheck(TypeChecker typeChecker)
                     throws TypingErrorException

Description copied from class: Expression

This method type-checks this expression in the context of the specified TypeChecker.

Overrides:

typeCheck in class Scope

Throws:

TypingErrorException

toString

public final java.lang.String toString()

Overrides:

toString in class Scope