1 files changed, 140 insertions, 0 deletions
diff --git a/cl-forth.lisp b/cl-forth.lisp
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+++ b/cl-forth.lisp
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+(in-package :cl-forth)
+
+(defparameter *identifiers* '(+ - |.| =))
+
+(defun is-identifier (sym)
+  (find sym *identifiers*))
+
+(defun make-token (sym? line col)
+  (if (or (is-identifier sym?) (numberp sym?))
+      (values (list sym? :line line :col col) nil)
+      (values (list sym? :line line :col col :error t) t)))
+
+(defun token-op (token)
+  (car token))
+
+(defun lex-line (line-stream line-num)
+  (iter (with col = 0)
+        (with has-err = nil)
+        (for next-char = (peek-char nil line-stream nil nil))
+        (until (null next-char))
+        (let ((flag t))
+          (cond ((char= #\. next-char)
+                 (collect (make-token '|.| line-num col) into tokens)
+                 (read-char line-stream))
+                ((char= #\Space next-char) (read-char line-stream))
+                ((char= #\; next-char) ;; and not in string
+                 (finish))
+                (t (setf flag nil)))
+          (when flag
+            (incf col)
+            (next-iteration)))
+        (for next-sym in-stream line-stream
+             using #'read-preserving-whitespace)
+        (multiple-value-bind (token err)
+            (make-token next-sym line-num col)
+          (collect token into tokens)
+          (when err ;; skip line on error and continue lexing
+            (setf has-err t)
+            (finish))
+          (incf col (length (princ-to-string next-sym))))
+        (finally (return (values tokens has-err)))))
+
+(defun lex-file (file-name &optional report-errors)
+  (let ((has-error nil))
+    (values
+     (with-open-file (str file-name)
+       (iter outer
+             (for line = (read-line str nil nil))
+             (until (null line))
+             (for line-num from 1)
+             (multiple-value-bind (tokens has-err)
+                 (lex-line (make-string-input-stream line) line-num)
+               (when has-err
+                 (setf has-error t)
+                 (when report-errors
+                   (format t "~a~%" line)
+                   (let ((err-token (find-if (lambda (tok) (find :error tok))
+                                             tokens)))
+                     (format t "~a^"
+                             (make-string (getf (cdr err-token) :col)
+                                          :initial-element #\Space)))))
+               (appending tokens))))
+     has-error)))
+
+;; (defun prog-from-tokens (tokens)
+;;   (iter (for token in tokens)
+;;         (let ((op (token-op token)))
+;;           (cond ((numberp op)
+;;                  (collect `(push ,op) result-type 'vector))
+;;                 (t (collect (list op) result-type 'vector))))))
+
+(defun parse-tokens (tokens)
+  (iter (with ops = (make-array (length tokens) :fill-pointer 0
+                                                :adjustable t))
+        (for i from 0)
+        (for token in tokens)
+        (let ((op (token-op token)))
+          (cond ((numberp op)
+                 (vector-push-extend `(push ,op) ops))
+                (t (vector-push-extend (list op) ops))))
+        (finally (return ops))))
+
+(defun make-program (file-name)
+  (multiple-value-bind (tokens has-error)
+      (lex-file file-name t)
+    (when has-error
+      (error "Can't generate program due to error during lexing"))
+    (parse-tokens tokens)))
+
+;; (defun *ops* '(push pop minus dump))
+
+(defun interpret-program (program)
+  (iter (with stack = (make-array 100 :fill-pointer 0 :adjustable t))
+        (for op in-sequence program)
+        (case (first op)
+          (push (vector-push-extend (second op) stack))
+          (+ (vector-push-extend (+ (vector-pop stack)
+                                    (vector-pop stack))
+                                 stack))
+          (- (vector-push-extend (let ((top (vector-pop stack)))
+                     (- (vector-pop stack) top))
+                   stack))
+          (|.| (print (vector-pop stack)))
+          (= (vector-push-extend (= (vector-pop stack)
+                                    (vector-pop stack))
+                                 stack))
+          (otherwise (error "op: ~a -- Not implemented yet" (first op))))))
+
+(defun gen-header (op str)
+  (format str "    ;; -- ~s --~%" op))
+
+;; (defun not-implemented (str)
+;;   (format str "    ;; -- TODO: not implemented --~%"))
+
+(defun generate-program (program &key (path "output.asm") (compile nil))
+  (with-open-file (out path :direction :output
+                            :if-exists :supersede)
+    (format out "~a~%" "segment .text")
+    (gen-dump out)
+    (format out "~{~a~%~}" '("global _start"
+                             "_start:"))
+    (iter (for op in-sequence program)
+          (gen-header op out)
+          (let ((op-fn (gethash (car op) *operations*)))
+            (if (null op-fn)
+                (format t "~s is not an op" (car op))
+                (apply op-fn out (cdr op)))))
+    (format out "~{~a~%~}" '("    mov rax, 60"
+                             "    mov rdi, 0"
+                             "    syscall")))
+  (when compile
+    (run `("nasm" "-felf64" ,path))
+    (let ((name (first (uiop:split-string path :separator '(#\.)))))
+      (run `("ld" "-o" ,name ,(concatenate 'string name ".o"))))))
+
+(defun compile-program (path)
+  (generate-program (make-program path) :compile t))
+
+
+