jif.types
Class LabelConstraint

java.lang.Object
  jif.types.LabelConstraint

public class LabelConstraint
extends java.lang.Object

A LabelConstraint represents a constraint on labels, which may either be an inequality or equality constraint. LabelConstraints are generated during type checking. LabelConstraints in turn produce Equations which are what the Solver will use to find a satisfying assignment for VarLabels. A LabelConstraint is not the same as a LabelConstraint, which by contrast is assumed to be satisfied.

Nested Class Summary

static class

LabelConstraint.Kind Kinds of constraint, either equality or inequality.

Field Summary

protected LabelEnv	env The environment under which this constraint needs to be satisfied.
static LabelConstraint.Kind	EQUAL An equality kind of constraint.
protected LabelConstraint.Kind	kind
static LabelConstraint.Kind	LEQ An inequality kind of constraint.
protected Label	lhs
protected LabelConstraintMessage	messages Error messages
protected NamedLabel	namedLHS Names for the LHS
protected NamedLabel	namedRHS Names for the RHS
protected polyglot.util.Position	pos
protected boolean	report Do we want to report a violation of this constraint, or report the error for a different constraint?
protected Label	rhs

Constructor Summary

LabelConstraint(NamedLabel lhs, LabelConstraint.Kind kind, NamedLabel rhs, LabelEnv env, polyglot.util.Position pos, LabelConstraintMessage msg, boolean report)

Method Summary

protected void	addLEQEqns(java.util.Collection eqns, Label left, Label right) Produce equations that require left to be less than or equal to right, and add them to eqns.
java.util.Map	definitions(VarMap bounds) Returns a Map of Strings to List[String]s which is the definitions/bounds of the NamedLabels, and the description of any components that appear in the NamedLabels.
java.lang.String	detailMsg() A detailed message to display if this constraint is violated.
LabelEnv	env()
java.util.Collection	getEquations() Produce a Collection of Equations for this constraint.
LabelConstraint.Kind	kind()
Label	lhs()
LabelConstraintMessage	messages()
java.lang.String	msg() A message to display if this constraint is violated.
protected java.util.Map	namedDescrips() Return a map from Strings to Strings, which are the descriptions of names in the left and right hand sides.
protected java.util.Map	namedLabels() Return a map from Strings to Labels, which are the named elements of the left and right hand sides.
NamedLabel	namedLhs()
NamedLabel	namedRhs()
polyglot.util.Position	position()
boolean	report()
Label	rhs()
java.lang.String	technicalMsg() A technical message to display if this constraint is violated.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

EQUAL

public static final LabelConstraint.Kind EQUAL

An equality kind of constraint. That is, the constraint requires that lhs <= rhs and rhs <= lhs.

LEQ

public static final LabelConstraint.Kind LEQ

An inequality kind of constraint. That is, the constraint requires that lhs <= rhs.

lhs

protected Label lhs

kind

protected LabelConstraint.Kind kind

rhs

protected Label rhs

env

protected LabelEnv env

The environment under which this constraint needs to be satisfied.

namedLHS

protected NamedLabel namedLHS

Names for the LHS

namedRHS

protected NamedLabel namedRHS

Names for the RHS

pos

protected polyglot.util.Position pos

report

protected boolean report

Do we want to report a violation of this constraint, or report the error for a different constraint?

messages

protected LabelConstraintMessage messages

Error messages

Constructor Detail

LabelConstraint

public LabelConstraint(NamedLabel lhs,
                       LabelConstraint.Kind kind,
                       NamedLabel rhs,
                       LabelEnv env,
                       polyglot.util.Position pos,
                       LabelConstraintMessage msg,
                       boolean report)

Method Detail

lhs

public Label lhs()

kind

public LabelConstraint.Kind kind()

rhs

public Label rhs()

namedLhs

public NamedLabel namedLhs()

namedRhs

public NamedLabel namedRhs()

env

public LabelEnv env()

position

public polyglot.util.Position position()

report

public boolean report()

messages

public LabelConstraintMessage messages()

msg

public java.lang.String msg()

A message to display if this constraint is violated. This message should be short, and explain without using typing rules what this constraint represents. It should not refer to the names of labels (i.e., names for NamedLabels.

detailMsg

public java.lang.String detailMsg()

A detailed message to display if this constraint is violated. This message may consist of several sentences, and may refer to the names of the labels, if NamedLabels are used.

technicalMsg

public java.lang.String technicalMsg()

A technical message to display if this constraint is violated. This message can refer to typing rules to explain what the constraint represents, and to names of labels, if NamedLabels are used.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

namedLabels

protected java.util.Map namedLabels()

Return a map from Strings to Labels, which are the named elements of the left and right hand sides.

namedDescrips

protected java.util.Map namedDescrips()

Return a map from Strings to Strings, which are the descriptions of names in the left and right hand sides.

definitions

public java.util.Map definitions(VarMap bounds)

Returns a Map of Strings to List[String]s which is the definitions/bounds of the NamedLabels, and the description of any components that appear in the NamedLabels. This map is used for verbose output to the user, to help explain the meaning of this constraint.

getEquations

public java.util.Collection getEquations()

Produce a Collection of Equations for this constraint.

addLEQEqns

protected void addLEQEqns(java.util.Collection eqns,
                          Label left,
                          Label right)

Produce equations that require left to be less than or equal to right, and add them to eqns.