Module aya.base

Package org.aya.tyck.unify

Class Unifier

java.lang.Object

org.aya.tyck.unify.TermComparator

org.aya.tyck.unify.Unifier

public final class Unifier
extends TermComparator

This class implements pattern unification with delayed constraints solving. It is extracted from TermComparator for modularity and readability.

See Also:

• Eta-contraction
• bidirectional conversion check
• the only intended API for conversion checking

Implementation Note:

in case TermComparator.compareUntyped(Term, Term, Sub, Sub) returns null, we will consider it a unification failure, so be careful when returning null.

Nested Class Summary

Nested classes/interfaces inherited from class org.aya.tyck.unify.TermComparator

TermComparator.FailureData, TermComparator.Sub

Field Summary

Fields inherited from class org.aya.tyck.unify.TermComparator

cmp, ctx, pos, reporter, state, traceBuilder

Constructor Summary

Constructors

Constructor	Description
Unifier(@NotNull org.aya.util.Ordering cmp, @NotNull org.aya.util.reporter.Reporter reporter, boolean allowVague, boolean allowConfused, Trace.Builder traceBuilder, @NotNull TyckState state, @NotNull org.aya.util.error.SourcePos pos, @NotNull LocalCtx ctx)

Method Summary

Modifier and Type	Method	Description
void	checkEqn(TyckState.Eqn eqn)
protected @Nullable Term	solveMeta(@NotNull Term preRhs, TermComparator.Sub lr, TermComparator.Sub rl, @NotNull MetaTerm lhs)

Methods inherited from class org.aya.tyck.unify.TermComparator

compare, compare, compareSort, compareUntyped, getFailure, tracing, withIntervals

Methods inherited from class java.lang.Object

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

Constructor Details

Unifier

public Unifier(@NotNull
 @NotNull org.aya.util.Ordering cmp,
 @NotNull
 @NotNull org.aya.util.reporter.Reporter reporter,
 boolean allowVague,
 boolean allowConfused,
 @Nullable
 Trace.Builder traceBuilder,
 @NotNull
 @NotNull TyckState state,
 @NotNull
 @NotNull org.aya.util.error.SourcePos pos,
 @NotNull
 @NotNull LocalCtx ctx)

Method Details

solveMeta

@Nullable
protected @Nullable Term solveMeta(@NotNull
 @NotNull Term preRhs,
 TermComparator.Sub lr,
 TermComparator.Sub rl,
 @NotNull
 @NotNull MetaTerm lhs)

Specified by:

solveMeta in class TermComparator

checkEqn

public void checkEqn(@NotNull
 TyckState.Eqn eqn)