;;; cl-scopes/forge - may the forge be with you!

;;;; A Forth-like interpreter implemented in Common Lisp.

(defpackage :scopes/forge
  (:use :common-lisp)
  (:export #:new-forge-env #:data-stack #:exec))

(in-package :scopes/forge)

(defclass forge-env ()
  ((data-stack :initform nil
			   :reader data-stack
			   :accessor data-stack!)))

(defun new-forge-env ()
  (make-instance 'forge-env))

(defun exec (fe code)
  (dolist (x code)
	(if (symbolp x)
      (funcall (find-symbol (symbol-name x) :scopes/forge) fe)
	  (pushd fe x))))

; forge primitives

(defun add (fe)
  (pushd fe (+ (popd fe) (popd fe))))

; internal definitions

(defun popd (fe)
  (pop (data-stack! fe)))

(defun pushd (fe v)
  (push v (data-stack! fe)))