X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=lispstrack.lisp;h=9395aec00cd88b7c7ab5a64af1170cec045663e0;hb=0051195db753db40c7b42ad1e947d2a606af12dd;hp=9add3b3c203695885be2d4ecc15142d2749a00b6;hpb=5f9cb325030a651bdf27771b4d3b5e7dc2849e8a;p=jscl.git

diff --git a/lispstrack.lisp b/lispstrack.lisp
index 9add3b3..9395aec 100644
--- a/lispstrack.lisp
+++ b/lispstrack.lisp
@@ -1,26 +1,20 @@
 ;;; Utils
 
+#+common-lisp
 (defmacro while (condition &body body)
   `(do ()
        ((not ,condition))
      ,@body))
 
+(defvar *newline* "
+")
+
 ;;; simplify me, please
 (defun concat (&rest strs)
   (reduce (lambda (s1 s2) (concatenate 'string s1 s2))
           strs
           :initial-value ""))
 
-
-(let ((counter 0))
-  (defun make-var-binding (symbol)
-    (cons symbol (format nil "v~d" (incf counter)))))
-
-(let ((counter 0))
-  (defun make-func-binding (symbol)
-    (cons symbol (format nil "f~d" (incf counter)))))
-
-
 ;;; Concatenate a list of strings, with a separator
 (defun join (list separator)
   (cond
@@ -33,16 +27,160 @@
              separator
              (join (cdr list) separator)))))
 
-;;; Compiler
+(defun join-trailing (list separator)
+  (if (null list)
+      ""
+      (concat (car list) separator (join-trailing (cdr list) separator))))
+
+(defun integer-to-string (x)
+  (if (zerop x)
+      "0"
+      (let ((digits nil))
+        (while (not (= x 0))
+          (push (mod x 10) digits)
+          (setq x (truncate x 10)))
+        (join (mapcar (lambda (d) (string (char "0123456789" d)))
+                      digits)
+              ""))))
+
+;;;; Reader
+
+;;; It is a basic Lisp reader. It does not use advanced stuff
+;;; intentionally, because we want to use it to bootstrap a simple
+;;; Lisp. The main entry point is the function `ls-read', which
+;;; accepts a strings as argument and return the Lisp expression.
+(defun make-string-stream (string)
+  (cons string 0))
+
+(defun %peek-char (stream)
+  (if (streamp stream)
+      (peek-char nil stream nil)
+      (and (< (cdr stream) (length (car stream)))
+           (char (car stream) (cdr stream)))))
+
+(defun %read-char (stream)
+  (if (streamp stream)
+      (read-char stream nil)
+      (and (< (cdr stream) (length (car stream)))
+           (prog1 (char (car stream) (cdr stream))
+             (incf (cdr stream))))))
+
+(defun whitespacep (ch)
+  (or (char= ch #\space) (char= ch #\newline) (char= ch #\tab)))
+
+(defun skip-whitespaces (stream)
+  (let (ch)
+    (setq ch (%peek-char stream))
+    (while (and ch (whitespacep ch))
+      (%read-char stream)
+      (setq ch (%peek-char stream)))))
+
+(defun terminalp (ch)
+  (or (null ch) (whitespacep ch) (char= #\) ch) (char= #\( ch)))
+
+(defun read-until (stream func)
+  (let ((string "")
+        (ch))
+    (setq ch (%peek-char stream))
+    (while (not (funcall func ch))
+      (setq string (concat string (string ch)))
+      (%read-char stream)
+      (setq ch (%peek-char stream)))
+    string))
+
+(defun skip-whitespaces-and-comments (stream)
+  (let (ch)
+    (skip-whitespaces stream)
+    (setq ch (%peek-char stream))
+    (while (and ch (eql ch #\;))
+      (read-until stream (lambda (x) (eql x #\newline)))
+      (skip-whitespaces stream)
+      (setq ch (%peek-char stream)))))
+
+(defun %read-list (stream)
+  (skip-whitespaces-and-comments stream)
+  (let ((ch (%peek-char stream)))
+    (cond
+      ((char= ch #\))
+       (%read-char stream)
+       nil)
+      ((char= ch #\.)
+       (%read-char stream)
+       (skip-whitespaces-and-comments stream)
+       (prog1 (ls-read stream)
+         (unless (char= (%read-char stream) #\))
+           (error "')' was expected."))))
+      (t
+       (cons (ls-read stream) (%read-list stream))))))
+
+(defvar *eof* (make-symbol "EOF"))
+(defun ls-read (stream)
+  (skip-whitespaces-and-comments stream)
+  (let ((ch (%peek-char stream)))
+    (cond
+      ((null ch)
+       *eof*)
+      ((char= ch #\()
+       (%read-char stream)
+       (%read-list stream))
+      ((char= ch #\')
+       (%read-char stream)
+       (list 'quote (ls-read stream)))
+      ((char= ch #\`)
+       (%read-char stream)
+       (list 'backquote (ls-read stream)))
+      ((char= ch #\")
+       (%read-char stream)
+       (prog1 (read-until stream (lambda (ch) (char= ch #\")))
+         (%read-char stream)))
+      ((char= ch #\,)
+       (%read-char stream)
+       (if (eql (%peek-char stream) #\@)
+           (progn (%read-char stream) (list 'unquote-splicing (ls-read stream)))
+           (list 'unquote (ls-read stream))))
+      ((char= ch #\#)
+       (%read-char stream)
+       (ecase (%read-char stream)
+         (#\'
+          (list 'function (ls-read stream)))
+         (#\+
+          (let ((feature (read-until stream #'terminalp)))
+            (cond
+              ((string= feature "common-lisp")
+               (ls-read stream);ignore
+               (ls-read stream))
+              ((string= feature "lispstrack")
+               (ls-read stream))
+              (t
+               (error "Unknown reader form.")))))))
+      (t
+       (let ((string (read-until stream #'terminalp)))
+         (if (every #'digit-char-p string)
+             (parse-integer string)
+             (intern (string-upcase string))))))))
+
+(defun ls-read-from-string (string)
+  (ls-read (make-string-stream string)))
+
+
+;;;; Compiler
+
+(let ((counter 0))
+  (defun make-var-binding (symbol)
+    (cons symbol (concat "v" (integer-to-string (incf counter))))))
+
+(let ((counter 0))
+  (defun make-func-binding (symbol)
+    (cons symbol (concat "f" (integer-to-string (incf counter))))))
 
 (defvar *compilations* nil)
 
 (defun ls-compile-block (sexps env fenv)
-  (concat (join (mapcar (lambda (x)
-                          (concat (ls-compile x env fenv) ";"))
-                        sexps)
-                ";
-")))
+  (join-trailing (mapcar (lambda (x)
+                           (ls-compile x env fenv))
+                         sexps)
+                 ";
+"))
 
 (defun extend-env (args env)
   (append (mapcar #'make-var-binding args) env))
@@ -52,7 +190,7 @@
 
 (defun ls-lookup (symbol env)
   (let ((binding (assoc symbol env)))
-    (and binding (format nil "~a" (cdr binding)))))
+    (and binding (cdr binding))))
 
 (defun lookup-variable (symbol env)
   (or (ls-lookup symbol env)
@@ -71,11 +209,16 @@
   `(push (list ',name (lambda (env fenv ,@args) ,@body))
          *compilations*))
 
+(defvar *toplevel-compilations*)
+
 (define-compilation if (condition true false)
-  (format nil "((~a)? (~a) : (~a))"
+  (concat "("
           (ls-compile condition env fenv)
+          " ? "
           (ls-compile true env fenv)
-          (ls-compile false env fenv)))
+          " : "
+          (ls-compile false env fenv)
+          ")"))
 
 ;;; Return the required args of a lambda list
 (defun lambda-list-required-argument (lambda-list)
@@ -94,36 +237,39 @@
               (join (mapcar (lambda (x) (lookup-variable x new-env))
                             required-arguments)
                     ",")
-              "){
-"
+              "){"
+              *newline*
               (if rest-argument
                   (concat "var " (lookup-variable rest-argument new-env)
                           " = arguments.slice("
-                          (prin1-to-string (length required-arguments)) ");
-")
+                          (prin1-to-string (length required-arguments))
+                          ");"
+                          *newline*)
                   "")
-
               (concat (ls-compile-block (butlast body) new-env fenv)
                       "return " (ls-compile (car (last body)) new-env fenv) ";")
-              "
-})"))))
+              *newline*
+              "})"))))
 
 (define-compilation fsetq (var val)
-  (format nil "~a = ~a" (lookup-function var fenv) (ls-compile val env fenv)))
+  (concat (lookup-function var fenv)
+          " = "
+          (ls-compile val env fenv)))
 
 (define-compilation setq (var val)
-  (format nil "~a = ~a" (lookup-variable var env) (ls-compile val env fenv)))
+  (concat (lookup-variable var env)
+          " = "
+           (ls-compile val env fenv)))
 
 
 ;;; Literals
 
-(defvar *literals* '())
-
 (defun literal->js (sexp)
   (cond
     ((null sexp) "undefined")
-    ((integerp sexp) (format nil "~a" sexp))
-    ((stringp sexp) (format nil "\"~a\"" sexp))
+    ((integerp sexp) (integer-to-string sexp))
+    ((stringp sexp) (concat "\"" sexp "\""))
+    ((symbolp sexp) (concat "{name: \"" (symbol-name sexp) "\"}"))
     ((consp sexp) (concat "{car: "
                           (literal->js (car sexp))
                           ", cdr: "
@@ -131,34 +277,88 @@
 
 (let ((counter 0))
   (defun literal (form)
-    (let ((var (format nil "l~d" (incf counter))))
-      (push (cons var (literal->js form)) *literals*)
+    (let ((var (concat "l" (integer-to-string (incf counter)))))
+      (push (concat "var " var " = " (literal->js form)) *toplevel-compilations*)
       var)))
 
 (define-compilation quote (sexp)
   (literal sexp))
 
 (define-compilation debug (form)
-  (format nil "console.log(~a)" (ls-compile form env fenv)))
+  (concat "console.log(" (ls-compile form env fenv) ")"))
 
 (define-compilation while (pred &rest body)
-  (format nil "(function(){while(~a){~a}})() "
-	  (ls-compile pred env fenv)
-	  (ls-compile-block body env fenv)))
+  (concat "(function(){ while("
+          (ls-compile pred env fenv)
+          "){"
+          (ls-compile-block body env fenv)
+          "}})()"))
 
+(define-compilation function (x)
+  (cond
+    ((and (listp x) (eq (car x) 'lambda))
+     (ls-compile x env fenv))
+    ((symbolp x)
+     (lookup-function x fenv))))
+
+#+common-lisp
 (defmacro eval-when-compile (&body body)
   `(eval-when (:compile-toplevel :execute)
      ,@body))
 
 (defvar *eval-when-compilations*)
 (define-compilation eval-when-compile (&rest body)
-  (setq *eval-when-compilations* "")
   (eval (cons 'progn body))
-  (if (string= *eval-when-compilations* "")
-      nil
-      *eval-when-compilations*))
+  nil)
+
+(defmacro define-transformation (name args form)
+  `(define-compilation ,name ,args
+     (ls-compile ,form env fenv)))
+
+(define-transformation progn (&rest body)
+  `((lambda () ,@body)))
+
+(define-transformation let (bindings &rest body)
+  `((lambda ,(mapcar 'car bindings) ,@body)
+    ,@(mapcar 'cadr bindings)))
+
+;;; A little backquote implementation without optimizations of any
+;;; kind for lispstrack.
+(defun backquote-expand-1 (form)
+  (cond
+    ((symbolp form)
+     (list 'quote form))
+    ((atom form)
+     form)
+    ((eq (car form) 'unquote)
+     (car form))
+    ((eq (car form) 'backquote)
+     (backquote-expand-1 (backquote-expand-1 (cadr form))))
+    (t
+     (cons 'append
+           (mapcar (lambda (s)
+                     (cond
+                       ((and (listp s) (eq (car s) 'unquote))
+                        (list 'list (cadr s)))
+                       ((and (listp s) (eq (car s) 'unquote-splicing))
+                        (cadr s))
+                       (t
+                        (list 'list (backquote-expand-1 s)))))
+                   form)))))
+
+(defun backquote-expand (form)
+  (if (and (listp form) (eq (car form) 'backquote))
+      (backquote-expand-1 (cadr form))
+      form))
+
+(defmacro backquote (form)
+  (backquote-expand-1 form))
+
+(define-transformation backquote (form)
+  (backquote-expand-1 form))
+
+;;; Primitives
 
-;;; aritmetic primitives
 (define-compilation + (x y)
   (concat "((" (ls-compile x env fenv) ") + (" (ls-compile y env fenv) "))"))
 
@@ -174,48 +374,67 @@
 (define-compilation = (x y)
   (concat "((" (ls-compile x env fenv) ") == (" (ls-compile y env fenv) "))"))
 
+(define-compilation null (x)
+  (concat "(" (ls-compile x env fenv) "== undefined)"))
+
 (define-compilation cons (x y)
-  (concat "(new Cons("y", " x "))"))
+  (concat "{car: " (ls-compile x env fenv) ", cdr: " (ls-compile y env fenv) "}"))
 
 (define-compilation car (x)
-  (concat "(x.car)"))
+  (concat "(" (ls-compile x env fenv) ").car"))
 
 (define-compilation cdr (x)
-  (concat "(x.cdr)"))
+  (concat "(" (ls-compile x env fenv) ").cdr"))
+
+
 
-(defmacro with-eval-when-compilation (&body body)
-  `(setq *eval-when-compilations*
-         (concat *eval-when-compilations* (progn ,@body))))
+(define-compilation symbol-name (x)
+  (concat "(" (ls-compile x env fenv) ").name"))
+
+(define-compilation eq (x y)
+  (concat "(" (ls-compile x env fenv) " === " (ls-compile y env fenv) ")"))
+
+(define-compilation code-char (x)
+  (concat "String.fromCharCode( " (ls-compile x env fenv) ")"))
 
 (defun %compile-defvar (name)
   (push (make-var-binding name) *env*)
-  (with-eval-when-compilation
-    (format nil "var ~a" (lookup-variable name *env*))))
+  (push (concat "var " (lookup-variable name *env*)) *toplevel-compilations*))
 
 (defun %compile-defun (name)
   (push (make-func-binding name) *fenv*)
-  (with-eval-when-compilation
-    (format nil "var ~a" (lookup-variable name *fenv*))))
+  (push (concat "var " (lookup-variable name *fenv*)) *toplevel-compilations*))
 
 (defun %compile-defmacro (name lambda)
   (push (cons name (cons 'macro lambda)) *fenv*))
 
-(defun compile-funcall (name args env fenv)
-  (format nil "~a(~{~a~^, ~})"
-          (lookup-function name fenv)
-          (mapcar (lambda (x) (ls-compile x env fenv)) args)))
-
 (defun ls-macroexpand-1 (form &optional env fenv)
   (let ((function (cdr (assoc (car form) *fenv*))))
     (if (and (listp function) (eq (car function) 'macro))
         (apply (eval (cdr function)) (cdr form))
         form)))
 
+(defun compile-funcall (function args env fenv)
+  (cond
+    ((symbolp function)
+     (concat (lookup-function function fenv)
+             "("
+             (join (mapcar (lambda (x) (ls-compile x env fenv)) args)
+                   ", ")
+             ")"))
+    ((and (listp function) (eq (car function) 'lambda))
+     (concat "(" (ls-compile function env fenv) ")("
+             (join (mapcar (lambda (x) (ls-compile x env fenv)) args)
+                   ", ")
+             ")"))
+    (t
+     (error "Invalid function designator ~a." function))))
+
 (defun ls-compile (sexp &optional env fenv)
   (cond
     ((symbolp sexp) (lookup-variable sexp env))
-    ((integerp sexp) (format nil "~a" sexp))
-    ((stringp sexp) (format nil "\"~a\"" sexp))
+    ((integerp sexp) (integer-to-string sexp))
+    ((stringp sexp) (concat "\"" sexp "\""))
     ((listp sexp)
      (let ((sexp (ls-macroexpand-1 sexp env fenv)))
        (let ((compiler-func (second (assoc (car sexp) *compilations*))))
@@ -224,28 +443,25 @@
              (compile-funcall (car sexp) (cdr sexp) env fenv)))))))
 
 (defun ls-compile-toplevel (sexp)
-  (setq *literals* nil)
+  (setq *toplevel-compilations* nil)
   (let ((code (ls-compile sexp)))
     (prog1
-        (concat (join (mapcar (lambda (lit)
-                                (concat "var " (car lit) " = " (cdr lit) ";
-"))
-                              *literals*)
+        (concat (join (mapcar (lambda (x) (concat x ";" *newline*))
+                              *toplevel-compilations*)
                       "")
                 code)
-      (setq *literals* nil))))
-
+      (setq *toplevel-compilations* nil))))
 
+#+common-lisp
 (defun ls-compile-file (filename output)
   (with-open-file (in filename)
     (with-open-file (out output :direction :output :if-exists :supersede)
       (loop
-         for x = (read in nil) while x
-         for compilation = (ls-compile x)
+         for x = (ls-read in)
+         until (eq x *eof*)
+         for compilation = (ls-compile-toplevel x)
          when compilation do (write-line (concat compilation "; ") out)))))
 
-
 ;;; Testing
-
 (defun compile-test ()
   (ls-compile-file "test.lisp" "test.js"))