+++ /dev/null
-;;; compiler-codege.lisp --- Naive Javascript unparser
-
-;; copyright (C) 2013 David Vazquez
-
-;; JSCL is free software: you can redistribute it and/or
-;; modify it under the terms of the GNU General Public License as
-;; published by the Free Software Foundation, either version 3 of the
-;; License, or (at your option) any later version.
-;;
-;; JSCL is distributed in the hope that it will be useful, but
-;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-;; General Public License for more details.
-;;
-;; You should have received a copy of the GNU General Public License
-;; along with JSCL. If not, see <http://www.gnu.org/licenses/>.
-
-;;; This code generator takes as input a S-expression representation
-;;; of the Javascript AST and generates Javascript code without
-;;; redundant syntax constructions like extra parenthesis.
-;;;
-;;; It is intended to be used with the new compiler. However, it is
-;;; quite independent so it has been integrated early in JSCL.
-
-(/debug "loading compiler-codegen.lisp!")
-
-(defvar *js-macros* nil)
-(defmacro define-js-macro (name lambda-list &body body)
- (let ((form (gensym)))
- `(push (cons ',name
- (lambda (,form)
- (block ,name
- (destructuring-bind ,lambda-list ,form
- ,@body))))
- *js-macros*)))
-
-(defun js-macroexpand (js)
- (if (and (consp js) (assoc (car js) *js-macros*))
- (let ((expander (cdr (assoc (car js) *js-macros*))))
- (multiple-value-bind (expansion stop-expand-p)
- (funcall expander (cdr js))
- (if stop-expand-p
- expansion
- (js-macroexpand expansion))))
- js))
-
-
-(defconstant no-comma 12)
-
-(defvar *js-output* t)
-
-;;; Two seperate functions are needed for escaping strings:
-;;; One for producing JavaScript string literals (which are singly or
-;;; doubly quoted)
-;;; And one for producing Lisp strings (which are only doubly quoted)
-;;;
-;;; The same function would suffice for both, but for javascript string
-;;; literals it is neater to use either depending on the context, e.g:
-;;; foo's => "foo's"
-;;; "foo" => '"foo"'
-;;; which avoids having to escape quotes where possible
-(defun js-escape-string (string)
- (let ((index 0)
- (size (length string))
- (seen-single-quote nil)
- (seen-double-quote nil))
- (flet ((%js-escape-string (string escape-single-quote-p)
- (let ((output "")
- (index 0))
- (while (< index size)
- (let ((ch (char string index)))
- (when (char= ch #\\)
- (setq output (concat output "\\")))
- (when (and escape-single-quote-p (char= ch #\'))
- (setq output (concat output "\\")))
- (when (char= ch #\newline)
- (setq output (concat output "\\"))
- (setq ch #\n))
- (setq output (concat output (string ch))))
- (incf index))
- output)))
- ;; First, scan the string for single/double quotes
- (while (< index size)
- (let ((ch (char string index)))
- (when (char= ch #\')
- (setq seen-single-quote t))
- (when (char= ch #\")
- (setq seen-double-quote t)))
- (incf index))
- ;; Then pick the appropriate way to escape the quotes
- (cond
- ((not seen-single-quote)
- (concat "'" (%js-escape-string string nil) "'"))
- ((not seen-double-quote)
- (concat "\"" (%js-escape-string string nil) "\""))
- (t (concat "'" (%js-escape-string string t) "'"))))))
-
-
-(defun js-format (fmt &rest args)
- (apply #'format *js-output* fmt args))
-
-(defun valid-js-identifier (string-designator)
- (let ((string (typecase string-designator
- (symbol (symbol-name string-designator))
- (string string-designator)
- (t
- (return-from valid-js-identifier (values nil nil))))))
- (flet ((constitutentp (ch)
- (or (alphanumericp ch) (member ch '(#\$ #\_)))))
- (if (and (every #'constitutentp string)
- (if (plusp (length string))
- (not (digit-char-p (char string 0)))
- t))
- (values (format nil "~a" string) t)
- (values nil nil)))))
-
-(defun js-identifier (string-designator)
- (multiple-value-bind (string valid)
- (valid-js-identifier string-designator)
- (unless valid
- (error "~S is not a valid Javascript identifier." string))
- (js-format "~a" string)))
-
-(defun js-primary-expr (form)
- (cond
- ((numberp form)
- (if (<= 0 form)
- (js-format "~a" form)
- (js-expr `(- ,(abs form)))))
- ((stringp form)
- (js-format "~a" (js-escape-string form)))
- ((symbolp form)
- (case form
- (true (js-format "true"))
- (false (js-format "false"))
- (null (js-format "null"))
- (this (js-format "this"))
- (undefined (js-format "undefined"))
- (otherwise
- (js-identifier form))))
- (t
- (error "Unknown Javascript syntax ~S." form))))
-
-(defun js-vector-initializer (vector)
- (let ((size (length vector)))
- (js-format "[")
- (dotimes (i (1- size))
- (let ((elt (aref vector i)))
- (unless (eq elt 'null)
- (js-expr elt no-comma))
- (js-format ",")))
- (when (plusp size)
- (js-expr (aref vector (1- size)) no-comma))
- (js-format "]")))
-
-(defun js-object-initializer (plist)
- (js-format "{")
- (do* ((tail plist (cddr tail)))
- ((null tail))
- (let ((key (car tail))
- (value (cadr tail)))
- (multiple-value-bind (identifier identifier-p) (valid-js-identifier key)
- (declare (ignore identifier))
- (if identifier-p
- (js-identifier key)
- (js-expr (string key) no-comma)))
- (js-format ": ")
- (js-expr value no-comma)
- (unless (null (cddr tail))
- (js-format ","))))
- (js-format "}"))
-
-(defun js-function (arguments &rest body)
- (js-format "function(")
- (when arguments
- (js-identifier (car arguments))
- (dolist (arg (cdr arguments))
- (js-format ",")
- (js-identifier arg)))
- (js-format ")")
- (js-stmt `(group ,@body) t))
-
-(defun check-lvalue (x)
- (unless (or (symbolp x)
- (nth-value 1 (valid-js-identifier x))
- (and (consp x)
- (member (car x) '(get = property))))
- (error "Bad Javascript lvalue ~S" x)))
-
-;;; Process the Javascript AST to reduce some syntax sugar.
-(defun js-expand-expr (form)
- (if (consp form)
- (case (car form)
- (+
- (case (length (cdr form))
- (1 `(unary+ ,(cadr form)))
- (t (reduce (lambda (x y) `(+ ,x ,y)) (cdr form)))))
- (-
- (case (length (cdr form))
- (1 `(unary- ,(cadr form)))
- (t (reduce (lambda (x y) `(- ,x ,y)) (cdr form)))))
- ((and or)
- (reduce (lambda (x y) `(,(car form) ,x ,y)) (cdr form)))
- ((progn comma)
- (reduce (lambda (x y) `(comma ,x ,y)) (cdr form) :from-end t))
- (t
- (js-macroexpand form)))
- form))
-
-(defun js-operator-expression (op args precedence associativity operand-order)
- (let ((op1 (car args))
- (op2 (cadr args)))
- (case op
- ;; Accessors
- (property
- (js-expr (car args) 0)
- (js-format "[")
- (js-expr (cadr args) no-comma)
- (js-format "]"))
- (get
- (multiple-value-bind (accessor accessorp)
- (valid-js-identifier (cadr args))
- (unless accessorp
- (error "Invalid accessor ~S" (cadr args)))
- (js-expr (car args) 0)
- (js-format ".")
- (js-identifier accessor)))
- ;; Function call
- (call
- (js-expr (car args) 1)
- (js-format "(")
- (when (cdr args)
- (js-expr (cadr args) no-comma)
- (dolist (operand (cddr args))
- (js-format ",")
- (js-expr operand no-comma)))
- (js-format ")"))
- ;; Object syntax
- (object
- (js-object-initializer args))
- ;; Function expressions
- (function
- (js-format "(")
- (apply #'js-function args)
- (js-format ")"))
- (t
- (labels ((low-precedence-p (op-precedence)
- (cond
- ((> op-precedence precedence))
- ((< op-precedence precedence) nil)
- (t (not (eq operand-order associativity)))))
-
- (%unary-op (operator string operator-precedence operator-associativity post lvalue)
- (when (eq op operator)
- (when lvalue (check-lvalue op1))
- (when (low-precedence-p operator-precedence) (js-format "("))
- (cond
- (post
- (js-expr op1 operator-precedence operator-associativity 'left)
- (js-format "~a" string))
- (t
- (js-format "~a" string)
- (js-expr op1 operator-precedence operator-associativity 'right)))
- (when (low-precedence-p operator-precedence) (js-format ")"))
- (return-from js-operator-expression)))
-
- (%binary-op (operator string operator-precedence operator-associativity lvalue)
- (when (eq op operator)
- (when lvalue (check-lvalue op1))
- (when (low-precedence-p operator-precedence) (js-format "("))
- (js-expr op1 operator-precedence operator-associativity 'left)
- (js-format "~a" string)
- (js-expr op2 operator-precedence operator-associativity 'right)
- (when (low-precedence-p operator-precedence) (js-format ")"))
- (return-from js-operator-expression))))
-
- (macrolet ((unary-op (operator string precedence associativity &key post lvalue)
- `(%unary-op ',operator ',string ',precedence ',associativity ',post ',lvalue))
- (binary-op (operator string precedence associativity &key lvalue)
- `(%binary-op ',operator ',string ',precedence ',associativity ',lvalue)))
-
- (unary-op pre++ "++" 2 right :lvalue t)
- (unary-op pre-- "--" 2 right :lvalue t)
- (unary-op post++ "++" 2 right :lvalue t :post t)
- (unary-op post-- "--" 2 right :lvalue t :post t)
- (unary-op not "!" 2 right)
- (unary-op bit-not "~" 2 right)
- ;; Note that the leading space is necessary because it
- ;; could break with post++, for example. TODO: Avoid
- ;; leading space when it's possible.
- (unary-op unary+ " +" 2 right)
- (unary-op unary- " -" 2 right)
- (unary-op delete "delete " 2 right)
- (unary-op void "void " 2 right)
- (unary-op typeof "typeof " 2 right)
- (unary-op new "new " 2 right)
-
- (binary-op * "*" 3 left)
- (binary-op / "/" 3 left)
- (binary-op mod "%" 3 left)
- (binary-op % "%" 3 left)
- (binary-op + "+" 4 left)
- (binary-op - "-" 5 left)
- (binary-op << "<<" 5 left)
- (binary-op >> "<<" 5 left)
- (binary-op >>> ">>>" 5 left)
- (binary-op <= "<=" 6 left)
- (binary-op < "<" 6 left)
- (binary-op > ">" 6 left)
- (binary-op >= ">=" 6 left)
- (binary-op instanceof " instanceof " 6 left)
- (binary-op in " in " 6 left)
- (binary-op == "==" 7 left)
- (binary-op != "!=" 7 left)
- (binary-op === "===" 7 left)
- (binary-op !== "!==" 7 left)
- (binary-op bit-and "&" 8 left)
- (binary-op bit-xor "^" 9 left)
- (binary-op bit-or "|" 10 left)
- (binary-op and "&&" 11 left)
- (binary-op or "||" 12 left)
- (binary-op = "=" 13 right :lvalue t)
- (binary-op += "+=" 13 right :lvalue t)
- (binary-op incf "+=" 13 right :lvalue t)
- (binary-op -= "-=" 13 right :lvalue t)
- (binary-op decf "-=" 13 right :lvalue t)
- (binary-op *= "*=" 13 right :lvalue t)
- (binary-op /= "*=" 13 right :lvalue t)
- (binary-op bit-xor= "^=" 13 right :lvalue t)
- (binary-op bit-and= "&=" 13 right :lvalue t)
- (binary-op bit-or= "|=" 13 right :lvalue t)
- (binary-op <<= "<<=" 13 right :lvalue t)
- (binary-op >>= ">>=" 13 right :lvalue t)
- (binary-op >>>= ">>>=" 13 right :lvalue t)
-
- (binary-op comma "," 13 right)
- (binary-op progn "," 13 right)
-
- (when (member op '(? if))
- (when (low-precedence-p 12) (js-format "("))
- (js-expr (first args) 12 'right 'left)
- (js-format "?")
- (js-expr (second args) 12 'right 'right)
- (js-format ":")
- (js-expr (third args) 12 'right 'right)
- (when (low-precedence-p 12) (js-format ")"))
- (return-from js-operator-expression))
-
- (error "Unknown operator `~S'" op)))))))
-
-(defun js-expr (form &optional (precedence 1000) associativity operand-order)
- (let ((form (js-expand-expr form)))
- (cond
- ((or (symbolp form) (numberp form) (stringp form))
- (js-primary-expr form))
- ((vectorp form)
- (js-vector-initializer form))
- (t
- (js-operator-expression (car form) (cdr form) precedence associativity operand-order)))))
-
-(defun js-expand-stmt (form)
- (cond
- ((and (consp form) (eq (car form) 'progn))
- (destructuring-bind (&body body) (cdr form)
- (cond
- ((null body)
- nil)
- ((null (cdr body))
- (js-expand-stmt (car body)))
- (t
- `(group ,@(cdr form))))))
- (t
- (js-macroexpand form))))
-
-(defun js-stmt (form &optional parent)
- (let ((form (js-expand-stmt form)))
- (flet ((js-stmt (x) (js-stmt x form)))
- (cond
- ((null form)
- (unless (or (and (consp parent) (eq (car parent) 'group))
- (null parent))
- (js-format ";")))
- ((atom form)
- (progn
- (js-expr form)
- (js-format ";")))
- (t
- (case (car form)
- (label
- (destructuring-bind (label &body body) (cdr form)
- (js-identifier label)
- (js-format ":")
- (js-stmt `(progn ,@body))))
- (break
- (destructuring-bind (&optional label) (cdr form)
- (js-format "break")
- (when label
- (js-format " ")
- (js-identifier label))
- (js-format ";")))
- (return
- (destructuring-bind (value) (cdr form)
- (js-format "return ")
- (js-expr value)
- (js-format ";")))
- (var
- (flet ((js-var (spec)
- (destructuring-bind (variable &optional initial)
- (ensure-list spec)
- (js-identifier variable)
- (when initial
- (js-format "=")
- (js-expr initial no-comma)))))
- (destructuring-bind (var &rest vars) (cdr form)
- (js-format "var ")
- (js-var var)
- (dolist (var vars)
- (js-format ",")
- (js-var var))
- (js-format ";"))))
- (if
- (destructuring-bind (condition true &optional false) (cdr form)
- (js-format "if (")
- (js-expr condition)
- (js-format ") ")
- (js-stmt true)
- (when false
- (js-format " else ")
- (js-stmt false))))
- (group
- (let ((in-group-p
- (or (null parent)
- (and (consp parent) (eq (car parent) 'group)))))
- (unless in-group-p (js-format "{"))
- (mapc #'js-stmt (cdr form))
- (unless in-group-p (js-format "}"))))
- (while
- (destructuring-bind (condition &body body) (cdr form)
- (js-format "while (")
- (js-expr condition)
- (js-format ")")
- (js-stmt `(progn ,@body))))
- (switch
- (destructuring-bind (value &rest cases) (cdr form)
- (js-format "switch(")
- (js-expr value)
- (js-format "){")
- (dolist (case cases)
- (cond
- ((and (consp case) (eq (car case) 'case))
- (js-format "case ")
- (let ((value (cadr case)))
- (unless (or (stringp value) (integerp value))
- (error "Non-constant switch case `~S'." value))
- (js-expr value))
- (js-format ":"))
- ((eq case 'default)
- (js-format "default:"))
- (t
- (js-stmt case))))
- (js-format "}")))
- (for
- (destructuring-bind ((start condition step) &body body) (cdr form)
- (js-format "for (")
- (js-expr start)
- (js-format ";")
- (js-expr condition)
- (js-format ";")
- (js-expr step)
- (js-format ")")
- (js-stmt `(progn ,@body))))
- (for-in
- (destructuring-bind ((x object) &body body) (cdr form)
- (js-format "for (")
- (js-identifier x)
- (js-format " in ")
- (js-expr object)
- (js-format ")")
- (js-stmt `(progn ,@body))))
- (try
- (destructuring-bind (&rest body) (cdr form)
- (js-format "try")
- (js-stmt `(group ,@body))))
- (catch
- (destructuring-bind ((var) &rest body) (cdr form)
- (js-format "catch (")
- (js-identifier var)
- (js-format ")")
- (js-stmt `(group ,@body))))
- (finally
- (destructuring-bind (&rest body) (cdr form)
- (js-format "finally")
- (js-stmt `(group ,@body))))
- (throw
- (destructuring-bind (object) (cdr form)
- (js-format "throw ")
- (js-expr object)
- (js-format ";")))
- (t
- (js-expr form)
- (js-format ";"))))))))
-
-(defun js (&rest stmts)
- (mapc #'js-stmt stmts)
- nil)
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