orc.type
Class Type

java.lang.Object
  orc.type.Type

Direct Known Subclasses:

ArrowType, BooleanType, Bot, DotType, EllipsisArrowType, LetType, Message, MultiType, NumberType, StringType, Top, TupleType, Tycon, TypeApplication, TypeInstance, TypeVariable

public abstract class Type
extends java.lang.Object

Abstract superclass of all types for the Orc typechecker. This typechecker is based on the local type inference algorithms described by Benjamin Pierce and David Turner in their paper entitled "Local Type Inference". It extends that inference strategy with tuples, library-defined type constructors, user-defined datatypes, variance annotations, and other small changes.

Author:

dkitchin

Field Summary

static Type	BLANK Placeholder for an unspecified type.
static Type	BOOLEAN
static Type	BOT
static Type	INTEGER
static Type	LET
static Type	NUMBER
static Type	STRING
static Type	TOP

Constructor Summary

Type()

Method Summary

void	addConstraints(Env<java.lang.Boolean> VX, Type T, Constraint[] C)
void	assertSubtype(Type that)
Tycon	asTycon()
Type	call(Env<Type> ctx, Env<Type> typectx, java.util.List<Arg> args, java.util.List<Type> typeActuals)
Type	call(java.util.List<Type> args)
boolean	closed()
Type	demote(Env<java.lang.Boolean> V)
boolean	equal(Type that)
Variance	findVariance(java.lang.Integer var)
java.util.Set<java.lang.Integer>	freeVars()
boolean	isBot()
boolean	isTop()
Type	join(Type that)
Type	meet(Type that)
Type	promote(Env<java.lang.Boolean> V)
Type	subst(Env<Type> ctx)
static java.util.List<Type>	substAll(java.util.List<Type> ts, Env<Type> ctx)
boolean	subtype(Type that)
boolean	supertype(Type that)
java.lang.String	toString()
Type	unwrapAs(Type T)
java.util.List<Variance>	variances()

Methods inherited from class java.lang.Object

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

Field Detail

TOP

public static final Type TOP

BOT

public static final Type BOT

NUMBER

public static final Type NUMBER

STRING

public static final Type STRING

BOOLEAN

public static final Type BOOLEAN

INTEGER

public static final Type INTEGER

LET

public static final Type LET

BLANK

public static final Type BLANK

Placeholder for an unspecified type. FIXME: should use a null type.

Constructor Detail

Type

public Type()

Method Detail

isTop

public boolean isTop()

isBot

public boolean isBot()

subtype

public boolean subtype(Type that)
                throws TypeException

Throws:

TypeException

assertSubtype

public void assertSubtype(Type that)
                   throws TypeException

Throws:

TypeException

supertype

public boolean supertype(Type that)
                  throws TypeException

Throws:

TypeException

equal

public boolean equal(Type that)
              throws TypeException

Throws:

TypeException

join

public Type join(Type that)
          throws TypeException

Throws:

TypeException

meet

public Type meet(Type that)
          throws TypeException

Throws:

TypeException

call

public Type call(Env<Type> ctx,
                 Env<Type> typectx,
                 java.util.List<Arg> args,
                 java.util.List<Type> typeActuals)
          throws TypeException

Throws:

TypeException

call

public Type call(java.util.List<Type> args)
          throws TypeException

Throws:

TypeException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

subst

public Type subst(Env<Type> ctx)
           throws TypeException

Throws:

TypeException

substAll

public static java.util.List<Type> substAll(java.util.List<Type> ts,
                                            Env<Type> ctx)
                                     throws TypeException

Throws:

TypeException

variances

public java.util.List<Variance> variances()
                                   throws TypeException

Throws:

TypeException

unwrapAs

public Type unwrapAs(Type T)
              throws TypeException

Throws:

TypeException

asTycon

public Tycon asTycon()
              throws TypeException

Throws:

TypeException

freeVars

public java.util.Set<java.lang.Integer> freeVars()

closed

public boolean closed()

findVariance

public Variance findVariance(java.lang.Integer var)
                      throws TypeException

Throws:

TypeException

promote

public Type promote(Env<java.lang.Boolean> V)
             throws TypeException

Throws:

TypeException

demote

public Type demote(Env<java.lang.Boolean> V)
            throws TypeException

Throws:

TypeException

addConstraints

public void addConstraints(Env<java.lang.Boolean> VX,
                           Type T,
                           Constraint[] C)
                    throws TypeException

Throws:

TypeException