Removed 'append' from runtime lib since Daniel Gackle provided a more concise macro...

[clinton/parenscript.git] / runtime / ps-runtime-lib.lisp

(in-package "PARENSCRIPT")

;;; Script of library functions you can include with your own code to
;;; provide standard Lisp functionality.

(defparameter *ps-lisp-library*
  '(progn
    (defun mapcar (fun &rest as)
      (let ((result-array (make-array)))
        (if (= 1 (length as))
            (dolist (element (aref as 0))
              ((@ result-array push) (fun element)))
            (dotimes (i (length (aref as 0)))
              (let ((args-array (mapcar (lambda (a) (return (aref a i))) as)))
                ((@ result-array push) ((@ fun apply) fun args-array)))))
        (return result-array)))

    (defun map-into (fn arr)
      "Call FN on each element in ARR, replace element with the return value."
      (let ((idx 0))
        (dolist (el arr)
          (setf (aref arr idx) (fn el))
          (setf idx (1+ idx))))
      (return arr))

    (defun map (fn arr)
      "Call FN on each element in ARR and return the returned values in a new array."
      ;; In newer versions of ECMAScript, this may call Array.map, too
      (let ((idx 0)
            (result (array)))
        (dolist (el arr)
          (setf (aref result idx) (fn el))
          (setf idx (1+ idx)))
        (return result)))

    (defun map-until (fn arr)
      "Call FN on each element in ARR until it returns something. If so return that value."
      (let ((result))
        (dolist (el arr)
          (setf result (fn el))
          (unless (= result undefined)
            (return result)))))

    (defun member (item arr)
      "Check if ITEM is a member of ARR."
      (dolist (el arr)
        (if (= el item)
            (return true)))
      (return false))

    (defun set-difference (arr arr-to-sub)
      "Return a new array with only those elements in ARR that are not in ARR-TO-SUB."
      (let ((idx 0)
            (result (array)))
        (dolist (el arr)
          (unless (member el arr-to-sub)
            (setf (aref result idx) el)
            (setf idx (1+ idx))))
        (return result)))

    (defun reduce (func list &optional init) ;; the use of init here is actually a bit broken wrt null
      (let* ((acc))
        (do* ((i (if init -1 0) (1+ i))
              (acc (if init init (elt list 0)) (func acc (elt list i))))
             ((>= i (1- (length list)))))
        (return acc)))))