+(defun !reduce (func list initial)
+ (if (null list)
+ initial
+ (!reduce func
+ (cdr list)
+ (funcall func initial (car list)))))
+
;;; Utils
-(defmacro while (condition &body body)
- `(do ()
- ((not ,condition))
- ,@body))
+#+common-lisp
+(progn
+ (defmacro while (condition &body body)
+ `(do ()
+ ((not ,condition))
+ ,@body))
-;;; simplify me, please
-(defun concat (&rest strs)
- (reduce (lambda (s1 s2) (concatenate 'string s1 s2))
- strs
- :initial-value ""))
+ (defun concat-two (s1 s2)
+ (concatenate 'string s1 s2)))
+(defvar *newline* "
+")
-(let ((counter 0))
- (defun make-binding (symbol)
- (cons symbol (format nil "V_~d" (incf counter)))))
+(defun concat (&rest strs)
+ (!reduce (lambda (s1 s2) (concat-two s1 s2))
+ strs
+ ""))
;;; Concatenate a list of strings, with a separator
(defun join (list separator)
separator
(join (cdr list) separator)))))
+(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))))))
-;;; Compiler
+(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)
+ (join-trailing (mapcar (lambda (x)
+ (ls-compile x env fenv))
+ sexps)
+ ";
+"))
+
(defun extend-env (args env)
- (append (mapcar #'make-binding args) env))
+ (append (mapcar #'make-var-binding args) env))
+
+(defparameter *env* '())
+(defparameter *fenv* '())
(defun ls-lookup (symbol env)
(let ((binding (assoc symbol env)))
- (if binding
- (format nil "~a" (cdr binding))
- (error "Undefined variable `~a'" symbol))))
+ (and binding (cdr binding))))
+
+(defun lookup-variable (symbol env)
+ (or (ls-lookup symbol env)
+ (ls-lookup symbol *env*)
+ (error "Undefined variable `~a'" symbol)))
+
+(defun lookup-function (symbol env)
+ (or (ls-lookup symbol env)
+ (ls-lookup symbol *fenv*)
+ (error "Undefined function `~a'" symbol)))
(defmacro define-compilation (name args &body body)
- "creates a new primitive `name' with parameters args and @body. The
-body can access to the local environment through the variable env"
- `(push (list ',name (lambda (env ,@args) ,@body))
+ ;; Creates a new primitive `name' with parameters args and
+ ;; @body. The body can access to the local environment through the
+ ;; variable ENV.
+ `(push (list ',name (lambda (env fenv ,@args) ,@body))
*compilations*))
+(defvar *toplevel-compilations*)
+
(define-compilation if (condition true false)
- (format nil "((~a)? (~a) : (~a))"
- (ls-compile condition env)
- (ls-compile true env)
- (ls-compile false env)))
-
-(define-compilation lambda (args &rest body)
- (let ((new-env (extend-env args env)))
- (concat "(function ("
- (join (mapcar (lambda (x) (ls-lookup x new-env))
- args)
- ",")
- "){
-"
- (ls-compile-block body new-env)
- "
-})")))
+ (concat "("
+ (ls-compile condition env fenv)
+ " ? "
+ (ls-compile true env fenv)
+ " : "
+ (ls-compile false env fenv)
+ ")"))
+
+;;; Return the required args of a lambda list
+(defun lambda-list-required-argument (lambda-list)
+ (if (or (null lambda-list) (eq (car lambda-list) '&rest))
+ nil
+ (cons (car lambda-list) (lambda-list-required-argument (cdr lambda-list)))))
+
+(defun lambda-list-rest-argument (lambda-list)
+ (second (member '&rest lambda-list)))
+
+(define-compilation lambda (lambda-list &rest body)
+ (let ((required-arguments (lambda-list-required-argument lambda-list))
+ (rest-argument (lambda-list-rest-argument lambda-list)))
+ (let ((new-env (extend-env (cons rest-argument required-arguments) env)))
+ (concat "(function ("
+ (join (mapcar (lambda (x) (lookup-variable x new-env))
+ required-arguments)
+ ",")
+ "){"
+ *newline*
+ (if rest-argument
+ (concat "var " (lookup-variable rest-argument new-env) ";" *newline*
+ "for (var i = arguments.length-1; i>="
+ (integer-to-string (length required-arguments))
+ "; i--)" *newline*
+ (lookup-variable rest-argument new-env) " = "
+ "{car: arguments[i], cdr: " (lookup-variable rest-argument new-env) "};"
+ *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)
+ (concat (lookup-function var fenv)
+ " = "
+ (ls-compile val env fenv)))
(define-compilation setq (var val)
- (format nil "~a = ~a" (ls-lookup var env) (ls-compile val env)))
+ (concat (lookup-variable var env)
+ " = "
+ (ls-compile val env fenv)))
+
+
+;;; Literals
-(defun lisp->js (sexp)
+(defun literal->js (sexp)
(cond
- ((integerp sexp) (format nil "~a" sexp))
- ((stringp sexp) (format nil "\"~a\"" sexp))
- ((listp sexp) (concat "[" (join (mapcar 'lisp->js sexp) ",") "]"))))
+ ((null sexp) "undefined")
+ ((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: "
+ (literal->js (cdr sexp)) "}"))))
+
+(let ((counter 0))
+ (defun literal (form)
+ (let ((var (concat "l" (integer-to-string (incf counter)))))
+ (push (concat "var " var " = " (literal->js form)) *toplevel-compilations*)
+ var)))
(define-compilation quote (sexp)
- (lisp->js sexp))
+ (literal sexp))
-(defparameter *env* '())
-(defparameter *env-fun* '())
+(define-compilation debug (form)
+ (concat "console.log(" (ls-compile form env fenv) ")"))
+
+(define-compilation while (pred &rest body)
+ (concat "(function(){ while("
+ (ls-compile pred env fenv)
+ "){"
+ (ls-compile-block body env fenv)
+ "}})()"))
-(defun ls-compile (sexp &optional env)
+(define-compilation function (x)
(cond
- ((symbolp sexp) (ls-lookup sexp env))
- ((integerp sexp) (format nil "~a" sexp))
- ((stringp sexp) (format nil " \"~a\" " sexp))
- ; list
+ ((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)
+ (eval (cons 'progn body))
+ 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
+
+(define-compilation + (x y)
+ (concat "((" (ls-compile x env fenv) ") + (" (ls-compile y env fenv) "))"))
+
+(define-compilation - (x y)
+ (concat "((" (ls-compile x env fenv) ") - (" (ls-compile y env fenv) "))"))
+
+(define-compilation * (x y)
+ (concat "((" (ls-compile x env fenv) ") * (" (ls-compile y env fenv) "))"))
+
+(define-compilation / (x y)
+ (concat "((" (ls-compile x env fenv) ") / (" (ls-compile y env fenv) "))"))
+
+(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 "{car: " (ls-compile x env fenv) ", cdr: " (ls-compile y env fenv) "}"))
+
+(define-compilation car (x)
+ (concat "(" (ls-compile x env fenv) ").car"))
+
+(define-compilation cdr (x)
+ (concat "(" (ls-compile x env fenv) ").cdr"))
+
+(define-compilation make-symbol (name)
+ (concat "{name: " (ls-compile name env fenv) "}"))
+
+(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) ")"))
+
+(define-compilation char (string index)
+ (concat "("
+ (ls-compile string env fenv)
+ ").charCodeAt("
+ (ls-compile index env fenv)
+ ")"))
+
+(define-compilation concat-two (string1 string2)
+ (concat "("
+ (ls-compile string1 env fenv)
+ ").concat("
+ (ls-compile string2 env fenv)
+ ")"))
+
+(define-compilation funcall (func &rest args)
+ (concat "("
+ (ls-compile func env fenv)
+ ")("
+ (join (mapcar (lambda (x)
+ (ls-compile x env fenv))
+ args)
+ ", ")
+ ")"))
+
+(define-compilation new ()
+ "{}")
+
+(define-compilation get (object key)
+ (concat "(" (ls-compile object env fenv) ")[" (ls-compile key env fenv) "]"))
+
+(define-compilation set (object key value)
+ (concat "(("
+ (ls-compile object env fenv)
+ ")["
+ (ls-compile key env fenv) "]"
+ " = " (ls-compile value env fenv) ")"))
+
+
+(defun %compile-defvar (name)
+ (push (make-var-binding name) *env*)
+ (push (concat "var " (lookup-variable name *env*)) *toplevel-compilations*))
+
+(defun %compile-defun (name)
+ (push (make-func-binding name) *fenv*)
+ (push (concat "var " (lookup-variable name *fenv*)) *toplevel-compilations*))
+
+(defun %compile-defmacro (name lambda)
+ (push (cons name (cons 'macro lambda)) *fenv*))
+
+(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) (integer-to-string sexp))
+ ((stringp sexp) (concat "\"" sexp "\""))
((listp sexp)
- (let ((compiler-func (second (assoc (car sexp) *compilations*))))
- (if compiler-func
- (apply compiler-func env (cdr sexp))
- ;; funcall
- )))))
-
-(defun ls-compile-block (sexps env)
- (concat (join (mapcar (lambda (x)
- (ls-compile x env))
- (butlast sexps))
- ";
-")
- ";
-return " (ls-compile (car (last sexps)) env) ";"))
+ (let ((sexp (ls-macroexpand-1 sexp env fenv)))
+ (let ((compiler-func (second (assoc (car sexp) *compilations*))))
+ (if compiler-func
+ (apply compiler-func env fenv (cdr sexp))
+ (compile-funcall (car sexp) (cdr sexp) env fenv)))))))
+
+(defun ls-compile-toplevel (sexp)
+ (setq *toplevel-compilations* nil)
+ (let ((code (ls-compile sexp)))
+ (prog1
+ (concat (join (mapcar (lambda (x) (concat x ";" *newline*))
+ *toplevel-compilations*)
+ "")
+ code)
+ (setq *toplevel-compilations* nil))))
+
+#+common-lisp
+(progn
+ (defun ls-compile-file (filename output)
+ (with-open-file (in filename)
+ (with-open-file (out output :direction :output :if-exists :supersede)
+ (loop
+ for x = (ls-read in)
+ until (eq x *eof*)
+ for compilation = (ls-compile-toplevel x)
+ when compilation do (write-line (concat compilation "; ") out)))))
+ (defun bootstrap ()
+ (ls-compile-file "lispstrack.lisp" "lispstrack.js")))