org.snapscript.tree.reference.ConstraintReference Maven / Gradle / Ivy
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Dynamic scripting for the JVM
package org.snapscript.tree.reference;
import java.util.List;
import org.snapscript.core.Entity;
import org.snapscript.core.Evaluation;
import org.snapscript.core.constraint.Constraint;
import org.snapscript.core.constraint.ConstraintDescription;
import org.snapscript.core.error.InternalStateException;
import org.snapscript.core.scope.Scope;
import org.snapscript.core.type.Type;
import org.snapscript.core.variable.Value;
public abstract class ConstraintReference extends Evaluation {
private volatile ConstraintValue value;
protected ConstraintReference() {
super();
}
@Override
public Constraint compile(Scope scope, Constraint left) throws Exception {
if(value == null) {
value = create(scope);
}
return value.constraint;
}
@Override
public Value evaluate(Scope scope, Value left) throws Exception {
if(value == null) {
value = create(scope);
}
return value;
}
protected abstract ConstraintValue create(Scope scope) throws Exception;
protected static class ConstraintValue extends Value {
private final Constraint constraint;
private final Value value;
public ConstraintValue(Constraint constraint, Value value, Entity entity) {
this.constraint = new ConstraintDefinition(constraint, entity);
this.value = value;
}
@Override
public Constraint getConstraint() {
return constraint;
}
@Override
public T getValue() {
return value.getValue();
}
@Override
public void setValue(Object value){
throw new InternalStateException("Illegal modification of literal '" + value + "'");
}
@Override
public String toString() {
return value.toString();
}
}
protected static class ConstraintDefinition extends Constraint {
private ConstraintDescription description;
private List generics;
private List imports;
private Constraint constraint;
private Type type;
private String name;
public ConstraintDefinition(Constraint constraint, Entity entity) {
this.description = new ConstraintDescription(constraint, entity);
this.constraint = constraint;
}
@Override
public List getImports(Scope scope) {
if(imports == null) {
imports = constraint.getImports(scope);
}
return imports;
}
@Override
public List getGenerics(Scope scope) {
if(generics == null) {
generics = constraint.getGenerics(scope);
}
return generics;
}
@Override
public Type getType(Scope scope) {
if(type == null) {
type = constraint.getType(scope);
}
return type;
}
@Override
public String getName(Scope scope) {
if(name == null) {
name = constraint.getName(scope);
}
return name;
}
@Override
public String toString() {
return description.toString();
}
}
}