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;; SPDX-License-Identifier: EUPL-1.2
;; SPDX-FileCopyrightText: 2025 Uko Kokņevičs <perkontevs@gmail.com>
(defpackage :ukkoclot/src/hash-tables
(:documentation "Hash-table-oriented utilities.")
(:use :c2cl)
(:import-from :alexandria :with-gensyms)
(:export :gethash-lazy))
(in-package :ukkoclot/src/hash-tables)
(defmacro gethash-lazy (key hash-table default-lazy)
"`gethash' alternative with lazily evaluated default value."
(with-gensyms (res unique)
`(let* ((,unique ',unique)
(,res (gethash ,key ,hash-table ,unique)))
(if (eq ,res ,unique)
,default-lazy
,res))))
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