// Copyright 2023 The Dawn & Tint Authors
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package cnf

import (
	"dawn.googlesource.com/dawn/tools/src/container"
)

// Optimize returns the expression with all duplicate unary expressions in the
// ORs removed. The returned expression is sorted.
func Optimize(e Expr) Expr {
	m := container.NewMap[Key, Ors]()
	for _, o := range e {
		b := unique(o)
		m.Add(b.Key(), b)
	}
	return m.Values()
}

// unique returns the o with all duplicate unary expressions removed
// The returned OR expression list is sorted.
func unique(o Ors) Ors {
	m := container.NewMap[Key, Unary]()
	for _, u := range o {
		m.Add(u.Key(), u)
	}
	return m.Values()
}