hlt.language.design.kernel

Class ArrayExtension

java.lang.Object

hlt.language.design.kernel.Expression

hlt.language.design.kernel.ProtoExpression

hlt.language.design.kernel.ArrayExtension

All Implemented Interfaces:

Locatable

public class ArrayExtension
extends ProtoExpression

This is the class denoting an array literal - i.e., expressions enumerating elements that comprise the extension of an array or map. This is always a unidimensional array. In addition, an array extension may be constrained by an index set coming from an ArrayInitializer. In this case, care must be taken to reconcile the contents of the extension with the constraining index set. This somewhat complicates (1) type-checking as it must proceed to verify that indexing types are such that they can be made to agree, and (2) compiling that must generate instructions to perform appropriate runtime tests.

Field Summary

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

VOID_ASSIGNMENTS

Constructor Summary

Constructors

Constructor and Description
ArrayExtension(java.util.AbstractList elements, java.util.AbstractList indices)

Method Summary

Methods

Modifier and Type	Method and Description
void	compile(Compiler compiler) compile the elements compile the size if there is no index set constraint: compile the indexable, if there is one generate MAKE_[ARRAY,MAP]_[I,R,O] if there is an index set constraint: compile the index set generate size tests and conversion check for index set generate MAKE_ARRAY_[I,R,O] or SHUFFLE_MAP_[I,R,O] depending on whether or not indexables have been reconciled with a permutation array
Expression	copy() Returns a deep copy of this expression.
Expression[]	elements()
Expression	indexable()
Expression	indexSet()
int	numberOfSubexpressions() Returns the number of subexpressions
void	setCheckedType() This method sets the final unambiguously checked type of this expression, possibly along with other final information that may be needed by the compiler for generating code.
void	setIndexSet(Expression indexSet)
Expression	setSubexpression(int n, Expression expression) Returns this expression after setting its n-th subexpression to the specified expression; if there is no subexpression at the given position, this throws a NoSuchSubexpressionException
int	size()
Expression	subexpression(int n) Returns the n-th subexpression of this expression; if there is no subexpression at the given position, this throws a NoSuchSubexpressionException
java.lang.String	toString()
void	typeCheck(TypeChecker typeChecker) Typechecking proceeds as follows: type-check all the elements to have the same type; if there is no indexable (i.e., this is not a map) force the indexer type to be int else (i.e., this is a set-indexed map) typecheck the indexable as a set unify the indexable type and the indexer type if there is an index set (i.e., this is constrained by an ArrayInitializer) typecheck the index set to be a legal indexing type unify the base type of the index set type with the indexable' base type if there is one type-check this array extension as an array with the extension's element type as array base type, and the array's indexer type as indexer type.
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.ProtoExpression

checkedType, setCheckedType, setType, type, typeRef

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayExtension

public ArrayExtension(java.util.AbstractList elements,
              java.util.AbstractList indices)

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.

Specified by:

copy in class Expression

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.

Specified by:

typedCopy in class Expression

setIndexSet

public final void setIndexSet(Expression indexSet)

size

public final int size()

numberOfSubexpressions

public final int numberOfSubexpressions()

Description copied from class: Expression

Returns the number of subexpressions

Overrides:

numberOfSubexpressions in class Expression

subexpression

public final Expression subexpression(int n)
                               throws NoSuchSubexpressionException

Description copied from class: Expression

Returns the n-th subexpression of this expression; if there is no subexpression at the given position, this throws a NoSuchSubexpressionException

Overrides:

subexpression in class Expression

Throws:

NoSuchSubexpressionException

setSubexpression

public final Expression setSubexpression(int n,
                          Expression expression)
                                  throws NoSuchSubexpressionException

Description copied from class: Expression

Returns this expression after setting its n-th subexpression to the specified expression; if there is no subexpression at the given position, this throws a NoSuchSubexpressionException

Overrides:

setSubexpression in class Expression

Throws:

NoSuchSubexpressionException

elements

public final Expression[] elements()

indexable

public final Expression indexable()

indexSet

public final Expression indexSet()

setCheckedType

public final void setCheckedType()

Description copied from class: Expression

This method sets the final unambiguously checked type of this expression, possibly along with other final information that may be needed by the compiler for generating code.

Specified by:

setCheckedType in class Expression

typeCheck

public final void typeCheck(TypeChecker typeChecker)
                     throws TypingErrorException

Typechecking proceeds as follows:

1. type-check all the elements to have the same type;
2. if there is no indexable (i.e., this is not a map)
   • force the indexer type to be int
3. else (i.e., this is a set-indexed map)
   • typecheck the indexable as a set
   • unify the indexable type and the indexer type
4. if there is an index set (i.e., this is constrained by an ArrayInitializer)
   • typecheck the index set to be a legal indexing type
   • unify the base type of the index set type with the indexable' base type if there is one
5. type-check this array extension as an array with the extension's element type as array base type, and the array's indexer type as indexer type.

Specified by:

typeCheck in class Expression

Throws:

TypingErrorException

compile

public final void compile(Compiler compiler)

1. compile the elements
2. compile the size
3. if there is no index set constraint:
   1. compile the indexable, if there is one
   2. generate MAKE_[ARRAY,MAP]_[I,R,O]
   if there is an index set constraint:
   1. compile the index set
   2. generate size tests and conversion check for index set
   3. generate MAKE_ARRAY_[I,R,O] or SHUFFLE_MAP_[I,R,O] depending on whether or not indexables have been reconciled with a permutation array

Specified by:

compile in class Expression

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object