Added string literals

cl-forth.lisp

@@ -1,7 +1,7 @@
 (in-package :cl-forth)
 
 (defun make-token (sym? line col)
-  (if (or (numberp sym?) (is-identifier sym?))
+  (if (or (numberp sym?) (stringp sym?) (is-identifier sym?))
       (values (list sym? :line line :col col) nil)
       (values (list sym? :line line :col col :error t) t)))
 
@@ -9,6 +9,17 @@
   (car token))
 
 ;;; LEXER
+(defun read-string (stream)
+  ;; TODO: Handle unmatched " and give proper error message
+  (with-output-to-string (str)
+    (iter (for ch = (read-char stream))
+          (cond ((char= ch #\")
+                 (finish))
+                ((and (char= ch #\\) (char= (peek-char nil stream) #\n))
+                 (read-char stream)
+                 (write-char #\Newline str))
+                (t (write-char ch str))))))
+
 (defun lex-line (line &optional (line-num 0))
   (iter (with line-stream = (make-string-input-stream line))
         (with col = 0)
@@ -25,6 +36,11 @@
             ((char= #\Space next-char) (read-char line-stream))
             ((char= #\; next-char) ;; and not in string
              (finish))
+            ((char= #\" next-char)
+             (read-char line-stream)
+             (collect (make-token (read-string line-stream)
+                                  line-num col)
+               into tokens))
             (t (setf flag nil)))
           (when flag
             (incf col)
@@ -95,7 +111,10 @@
         (for token in tokens)
         (let ((op (token-op token)))
           (cond ((numberp op)
-                 (vector-push-extend `(push ,op) ops))
+                 (vector-push-extend `(push-int ,op) ops))
+                ((stringp op)
+                 (vector-push-extend `(push-str ,(length op) ,i ,op)
+                                     ops))
                 ((string= 'ise op)
                  (push (list 'ise i) stack)
                  (vector-push-extend (list 'ise nil) ops))