51 lines
1.1 KiB
Common Lisp
51 lines
1.1 KiB
Common Lisp
;;; cl-scopes/forge - may the forge be with you!
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;;;; A Forth-like interpreter implemented in Common Lisp.
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(defpackage :scopes/forge
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(:use :common-lisp)
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(:export #:forge-env #:data-stack #:exec))
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(in-package :scopes/forge)
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(defvar *builtins* (make-hash-table :test 'equalp))
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(defclass forge-env ()
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((data-stack :initform nil
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:reader data-stack
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:accessor data-stack!)
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(vocabulary :initform (list *builtins*)
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:accessor vocabulary)))
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(defun forge-env ()
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(make-instance 'forge-env))
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(defun exec (fe code)
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(dolist (x code)
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(if (symbolp x)
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(funcall (find-word (vocabulary fe) x) fe)
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(pushd fe x))))
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(defun register (voc key fn)
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(setf (gethash (string-downcase (symbol-name key)) voc) fn))
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(defun find-word (vocab key)
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(let ((k (string-downcase (symbol-name key))) (result nil))
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(dolist (voc vocab)
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(let ((v (gethash k voc)))
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(if v (return v))))))
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; built-in primitives
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(defun reg-b (key fn) (register *builtins* key fn))
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(reg-b 'add #'(lambda (fe) (pushd fe (+ (popd fe) (popd fe)))))
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; internal definitions
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(defun popd (fe)
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(pop (data-stack! fe)))
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(defun pushd (fe v)
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(push v (data-stack! fe)))
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