;;;; cl-scopes/util/index

;;;; smart string-based indexes e.g. for queryable registries

(defpackage :scopes/util/index
  (:use :common-lisp)
  (:local-nicknames (:alx :alexandria))
  (:export #:create #:put #:query))

(in-package :scopes/util/index)

(defclass index ()
  ((data :reader data :initform (make-hash-table :test #'equal))))

(defun create ()
  (make-instance 'index))

(defgeneric put (idx key value)
  (:method ((idx index) key value)
    (let* ((data (data idx))
           (cur (gethash key data)))
      (setf (gethash key data) (cons value cur)))))

(defgeneric query (idx pat)
  (:method ((idx index) pat)
    (if (equal pat "*")
      (alx:flatten (alx:hash-table-values (data idx)))
      (gethash pat (data idx)))))