;;;# ParenScript Language Reference
+;;; Create a useful package for the code here...
+(in-package #:cl-user)
+(defpackage #:ps-ref (:use #:ps))
+(in-package #:ps-ref)
+
;;; This chapters describes the core constructs of ParenScript, as
;;; well as its compilation model. This chapter is aimed to be a
;;; comprehensive reference for ParenScript developers. Programmers
(+ i (if 1 2 3)) => i + (1 ? 2 : 3)
(if 1 2 3)
- => if (1) {
- 2;
- } else {
- 3;
- }
+=> if (1) {
+ 2;
+ } else {
+ 3;
+ }
;;;# Symbol conversion
;;;t \index{symbol}
! ~ ++ -- * / % + - << >> >>> < > <= >= == != ==== !== & ^ | && || *=
/= %= += -= <<= >>= >>>= &= ^= |= 1- 1+ ABSTRACT AND AREF ARRAY
BOOLEAN BREAK BYTE CASE CATCH CC-IF CHAR CLASS COMMA CONST CONTINUE
-CREATE DEBUGGER DECF DEFAULT DEFUN DEFVAR DELETE DO DOEACH DOLIST
-DOTIMES DOUBLE ELSE ENUM EQL EXPORT EXTENDS FALSE FINAL FINALLY FLOAT
-FLOOR FOR FUNCTION GOTO IF IMPLEMENTS IMPORT IN INCF INSTANCEOF INT
-INTERFACE JS LAMBDA LET* LEXICAL-LET* LISP LIST LONG MAKE-ARRAY NATIVE
-NEW NIL NOT OR PACKAGE PRIVATE PROGN PROTECTED PUBLIC RANDOM REGEX
-RETURN SETF SHORT SLOT-VALUE STATIC SUPER SWITCH SYMBOL-MACROLET
-SYNCHRONIZED T THIS THROW THROWS TRANSIENT TRY TYPEOF UNDEFINED UNLESS
-VAR VOID VOLATILE WHEN WHILE WITH WITH-SLOTS
+CREATE DEBUGGER DECF DEFAULT DEFUN DEFVAR DELETE DO DO* DOEACH DOLIST
+DOTIMES DOUBLE ELSE ENUM EQL EXPORT EXTENDS F FALSE FINAL FINALLY
+FLOAT FLOOR FOR FOR-IN FUNCTION GOTO IF IMPLEMENTS IMPORT IN INCF
+INSTANCEOF INT INTERFACE JS LABELED-FOR LAMBDA LET LET* LEXICAL-LET
+LEXICAL-LET* LISP LIST LONG MAKE-ARRAY NATIVE NEW NIL NOT OR PACKAGE
+PRIVATE PROGN PROTECTED PUBLIC RANDOM REGEX RETURN SETF SHORT
+SLOT-VALUE STATIC SUPER SWITCH SYMBOL-MACROLET SYNCHRONIZED T THIS
+THROW THROWS TRANSIENT TRY TYPEOF UNDEFINED UNLESS VAR VOID VOLATILE
+WHEN WHILE WITH WITH-SLOTS
;;;# Literal values
;;;t \index{literal value}
(array (array 2 3)
(array "foobar" "bratzel bub"))
- => [ [ 2, 3 ], [ 'foobar', 'bratzel bub' ] ]
+=> [ [ 2, 3 ], [ 'foobar', 'bratzel bub' ] ]
;;; Arrays can also be created with a call to the `Array' function
;;; using the `MAKE-ARRAY'. The two forms have the exact same semantic
(make-array
(make-array 2 3)
(make-array "foobar" "bratzel bub"))
- => new Array(new Array(2, 3), new Array('foobar', 'bratzel bub'))
+=> new Array(new Array(2, 3), new Array('foobar', 'bratzel bub'))
;;; Indexing arrays in ParenScript is done using the form `AREF'. Note
;;; that JavaScript knows of no such thing as an array. Subscripting
;;; more "lispy", the property names can be keywords.
(create :foo "bar" :blorg 1)
- => { foo : 'bar',
- blorg : 1 }
+=> { foo : 'bar', blorg : 1 }
(create :foo "hihi"
:blorg (array 1 2 3)
:another-object (create :schtrunz 1))
- => { foo : 'hihi',
- blorg : [ 1, 2, 3 ],
- anotherObject : { schtrunz : 1 } }
+=> { foo : 'hihi',
+ blorg : [ 1, 2, 3 ],
+ anotherObject : { schtrunz : 1 } }
;;; Object properties can be accessed using the `SLOT-VALUE' form,
;;; which takes an object and a slot-name.
(with-slots (a b c) this
(+ a b c))
- => this.a + this.b + this.c;
+=> this.a + this.b + this.c;
;;;## Regular Expression literals
;;;t \index{REGEX}
;;;## Literal symbols
;;;t \index{T}
+;;;t \index{F}
;;;t \index{FALSE}
;;;t \index{NIL}
;;;t \index{UNDEFINED}
;;;t \index{null}
;;;t \index{true}
-; T, FALSE, NIL, UNDEFINED, THIS
+; T, F, FALSE, NIL, UNDEFINED, THIS
-;;; The Lisp symbols `T' and `FALSE' are converted to their JavaScript
-;;; boolean equivalents `true' and `false'.
+;;; The Lisp symbols `T' and `FALSE' (or `F') are converted to their
+;;; JavaScript boolean equivalents `true' and `false'.
T => true
FALSE => false
+F => false
+
;;; The Lisp symbol `NIL' is converted to the JavaScript keyword
;;; `null'.
(blorg 1 2) => blorg(1, 2)
(foobar (blorg 1 2) (blabla 3 4) (array 2 3 4))
- => foobar(blorg(1, 2), blabla(3, 4), [ 2, 3, 4 ])
+=> foobar(blorg(1, 2), blabla(3, 4), [ 2, 3, 4 ])
((aref foo i) 1 2) => foo[i](1, 2)
(this.blorg 1 2) => this.blorg(1, 2)
(.blorg (aref foobar 1) NIL T)
- => foobar[1].blorg(null, true)
+=> foobar[1].blorg(null, true)
;;;# Operator Expressions
;;;t \index{operator}
;;; according to the JavaScript operator precedence that can be found
;;; in table form at:
- http://www.codehouse.com/javascript/precedence/
+;;; http://www.codehouse.com/javascript/precedence/
(* 1 (+ 2 3 4) 4 (/ 6 7))
- => 1 * (2 + 3 + 4) * 4 * (6 / 7)
+=> 1 * (2 + 3 + 4) * 4 * (6 / 7)
;;; The pre increment and decrement operators are also
;;; available. `INCF' and `DECF' are the pre-incrementing and
;;; For example, in a statement context:
(progn (blorg i) (blafoo i))
- => blorg(i);
- blafoo(i);
+=> blorg(i);
+ blafoo(i);
;;; In an expression context:
(+ i (progn (blorg i) (blafoo i)))
- => i + (blorg(i), blafoo(i))
+=> i + (blorg(i), blafoo(i))
;;; A `PROGN' form doesn't lead to additional indentation or
;;; additional braces around it's body.
(defun a-function (a b)
(return (+ a b)))
- => function aFunction(a, b) {
+=> function aFunction(a, b) {
return a + b;
- }
+ }
;;; Anonymous functions can be created using the `LAMBDA' form, which
;;; is the same as `DEFUN', but without function name. In fact,
;;; `LAMBDA' creates a `DEFUN' with an empty function name.
(lambda (a b) (return (+ a b)))
- => function (a, b) {
+=> function (a, b) {
return a + b;
- }
+ }
;;;# Assignment
;;;t \index{assignment}
;;;t \index{SETF}
+;;;t \index{PSETF}
+;;;t \index{SETQ}
+;;;t \index{PSETQ}
;;;t \index{DEFSETF}
;;;t \index{assignment operator}
; (SETF {lhs rhs}*)
+; (PSETF {lhs rhs}*)
;
; lhs ::= a ParenScript left hand side expression
; rhs ::= a ParenScript expression
-;;; Assignment is done using the `SETF' form, which is transformed
-;;; into a series of assignments using the JavaScript `=' operator.
+; (SETQ {lhs rhs}*)
+; (PSETQ {lhs rhs}*)
+;
+; lhs ::= a ParenScript symbol
+; rhs ::= a ParenScript expression
+
+;;; Assignment is done using the `SETF', `PSETF', `SETQ', and `PSETQ'
+;;; forms, which are transformed into a series of assignments using
+;;; the JavaScript `=' operator.
(setf a 1) => a = 1;
(setf a 2 b 3 c 4 x (+ a b c))
- => a = 2;
- b = 3;
- c = 4;
- x = a + b + c;
+=> a = 2;
+ b = 3;
+ c = 4;
+ x = a + b + c;
;;; The `SETF' form can transform assignments of a variable with an
;;; operator expression using this variable into a more "efficient"
(setf a (- 1 a)) => a = 1 - a;
+;;; The `PSETF' and `PSETQ' forms perform parallel assignment of
+;;; places or variables using a number of temporary variables created
+;;; by `PS-GENSYM'. For example:
+
+(let* ((a 1) (b 2))
+ (psetf a b b a))
+=> var a = 1;
+ var b = 2;
+ var _js1 = b;
+ var _js2 = a;
+ a = _js1;
+ b = _js2;
+
+;;; The `SETQ' and `PSETQ' forms operate identically to `SETF' and
+;;; `PSETF', but throw a compile-time error if the left-hand side form
+;;; is not a symbol. For example:
+
+(setq a 1) => a = 1;
+
+;; but...
+
+(setq (aref a 0) 1)
+;; => ERROR: The value (AREF A 0) is not of type SYMBOL.
+
;;; New types of setf places can be defined in one of two ways: using
;;; `DEFSETF' or using `DEFUN' with a setf function name; both are
;;; analogous to their Common Lisp counterparts.
(defun (setf color) (new-color el)
(setf (slot-value (slot-value el 'style) 'color) new-color))
- => function __setf_color(newColor, el) {
+=> function __setf_color(newColor, el) {
el.style.color = newColor;
- };
+ };
(setf (color some-div) (+ 23 "em"))
- => var _js2 = someDiv;
- var _js1 = 23 + 'em';
- __setf_color(_js1, _js2);
-
+=> var _js2 = someDiv;
+ var _js1 = 23 + 'em';
+ __setf_color(_js1, _js2);
;;; Note that temporary variables are generated to preserve evaluation
;;; order of the arguments as they would be in Lisp.
;;; provide a uniform protocol for positioning elements in HTML pages:
(defsetf left (el) (offset)
- `(setf (slot-value (slot-value ,el 'style) 'left) ,offset)) => null
+ `(setf (slot-value (slot-value ,el 'style) 'left) ,offset))
+=> null
(setf (left some-div) (+ 123 "px"))
- => var _js2 = someDiv;
- var _js1 = 123 + 'px';
- _js2.style.left = _js1;
+=> var _js2 = someDiv;
+ var _js1 = 123 + 'px';
+ _js2.style.left = _js1;
(progn (defmacro left (el)
`(slot-value ,el 'offset-left))
(left some-div))
- => someDiv.offsetLeft;
+=> someDiv.offsetLeft;
;;;# Single argument statements
;;;t \index{single-argument statement}
(if (= (typeof blorg) *string)
(alert (+ "blorg is a string: " blorg))
(alert "blorg is not a string"))
- => if (typeof blorg == String) {
+=> if (typeof blorg == String) {
alert('blorg is a string: ' + blorg);
- } else {
+ } else {
alert('blorg is not a string');
- }
+ }
;;;# Conditional Statements
;;;t \index{conditional statements}
(if (blorg.is-correct)
(progn (carry-on) (return i))
(alert "blorg is not correct!"))
- => if (blorg.isCorrect()) {
- carryOn();
- return i;
- } else {
- alert('blorg is not correct!');
- }
+=> if (blorg.isCorrect()) {
+ carryOn();
+ return i;
+ } else {
+ alert('blorg is not correct!');
+ }
(+ i (if (blorg.add-one) 1 2))
- => i + (blorg.addOne() ? 1 : 2)
+=> i + (blorg.addOne() ? 1 : 2)
;;; The `WHEN' and `UNLESS' forms can be used as shortcuts for the
;;; `IF' form.
(when (blorg.is-correct)
(carry-on)
(return i))
- => if (blorg.isCorrect()) {
- carryOn();
- return i;
- }
+=> if (blorg.isCorrect()) {
+ carryOn();
+ return i;
+ }
(unless (blorg.is-correct)
(alert "blorg is not correct!"))
- => if (!blorg.isCorrect()) {
- alert('blorg is not correct!');
- }
+=> if (!blorg.isCorrect()) {
+ alert('blorg is not correct!');
+ }
;;;# Variable declaration
;;;t \index{variable}
;;;t \index{scoping}
;;;t \index{DEFVAR}
;;;t \index{VAR}
+;;;t \index{LET}
;;;t \index{LET*}
+;;;t \index{LEXICAL-LET}
;;;t \index{LEXICAL-LET*}
; (DEFVAR var {value}?)
; (VAR var {value}?)
-; (LET* ({var | (var value)}) body)
-; (LEXICAL-LET* ({var | (var value)}) body)
+; (LET ({var | (var value)}*) body)
+; (LET* ({var | (var value)}*) body)
+; (LEXICAL-LET ({var | (var value)}*) body)
+; (LEXICAL-LET* ({var | (var value)}*) body)
;
; var ::= a Lisp symbol
; value ::= a ParenScript expression
(defvar *a* (array 1 2 3)) => var A = [ 1, 2, 3 ]
;;; One feature present in Parenscript that is not part of Common Lisp
-;;; are lexically-scoped global variables, which are declared using
+;;; is lexically-scoped function variables, which are declared using
;;; the `VAR' special form.
-;;; Parenscript provides two special forms for manipulating local
-;;; variables: `LET*' and `LEXICAL-LET*'. Both bind their variable
-;;; lists sequentially, as indicated by the '*' at the end of their
-;;; names, however `LET*' does so using a simple JavaScript
-;;; assignment, while `LEXICAL-LET*' actually introduces a new lexical
-;;; environment for the variable bindings by creating and populating a
-;;; new object and using it as the lexical context for the JavaScript
-;;; 'with' form.
-
-(if (= i 1)
- (let* ((blorg "hallo"))
- (alert blorg))
- (let* ((blorg "blitzel"))
- (alert blorg)))
- => if (i == 1) {
- var blorg = 'hallo';
- alert(blorg);
- } else {
- var blorg = 'blitzel';
- alert(blorg);
- }
-
-(if (= i 1)
- (lexical-let* ((blorg "hallo"))
- (alert blorg))
- (lexical-let* ((blorg "blitzel"))
- (alert blorg)))
- => if (i == 1) {
- (function () {
- var newlexicalcontext1 = new Object;
- newlexicalcontext1['blorg'] = 'hallo';
- with (newlexicalcontext1) {
- alert(blorg);
- };
- })();
- } else {
- (function () {
- var newlexicalcontext3 = new Object;
- newlexicalcontext3['blorg'] = 'blitzel';
- with (newlexicalcontext3) {
- alert(blorg);
- };
- })();
- }
+;;; Parenscript provides two versions of the `LET' and `LET*' special
+;;; forms for manipulating local variables: `SIMPLE-LET' /
+;;; `SIMPLE-LET*' and `LEXICAL-LET' / `LEXICAL-LET*'. By default,
+;;; `LET' and `LET*' are aliased to `SIMPLE-LET' and `SIMPLE-LET*',
+;;; respectively.
+
+;;; `SIMPLE-LET' and `SIMPLE-LET*' bind their variable lists using
+;;; simple JavaScript assignment. This means that you cannot rely on
+;;; the bindings going out of scope at the end of the form.
+
+;;; `LEXICAL-LET' and `LEXICAL-LET*' actually introduce new lexical
+;;; environments for the variable bindings by creating anonymous
+;;; functions.
+
+;;; As you would expect, `SIMPLE-LET' and `LEXICAL-LET' do parallel
+;;; binding of their variable lists, while `SIMPLE-LET*' and
+;;; `LEXICAL-LET*' bind their variable lists sequentially.
+
+;;; examples:
+
+(simple-let* ((a 0) (b 1))
+ (alert (+ a b)))
+=> var a = 0;
+ var b = 1;
+ alert(a + b);
+
+(simple-let* ((a "World") (b "Hello"))
+ (simple-let ((a b) (b a))
+ (alert (+ a b))))
+=> var a = 'World';
+ var b = 'Hello';
+ var _js_a1 = b;
+ var _js_b2 = a;
+ var a = _js_a1;
+ var b = _js_b2;
+ delete _js_a1;
+ delete _js_b2;
+ alert(a + b);
+
+(simple-let* ((a 0) (b 1))
+ (lexical-let* ((a 9) (b 8))
+ (alert (+ a b)))
+ (alert (+ a b)))
+=> var a = 0;
+ var b = 1;
+ (function () {
+ var a = 9;
+ var b = 8;
+ alert(a + b);
+ })();
+ alert(a + b);
+
+(simple-let* ((a "World") (b "Hello"))
+ (lexical-let ((a b) (b a))
+ (alert (+ a b)))
+ (alert (+ a b)))
+=> var a = 'World';
+ var b = 'Hello';
+ (function (a, b) {
+ alert(a + b);
+ })(b, a);
+ alert(a + b);
;;; Moreover, beware that scoping rules in Lisp and JavaScript are
;;; quite different. For example, don't rely on closures capturing
;;;t \index{DOEACH}
;;;t \index{WHILE}
-; (DO ({var | (var {init}? {step}?)}*) (end-test) body)
-; (DOTIMES (var numeric-form) body)
-; (DOLIST (var list-form) body)
-; (DOEACH (var object) body)
+; (DO ({var | (var {init}? {step}?)}*) (end-test {result}?) body)
+; (DO* ({var | (var {init}? {step}?)}*) (end-test {result}?) body)
+; (DOTIMES (var numeric-form {result}?) body)
+; (DOLIST (var list-form {result}?) body)
+; (DOEACH ({var | (key value)} object-form {result}?) body)
; (WHILE end-test body)
;
; var ::= a Lisp symbol
; numeric-form ::= a ParenScript expression resulting in a number
; list-form ::= a ParenScript expression resulting in an array
-; object ::= a ParenScript expression resulting in an object
+; object-form ::= a ParenScript expression resulting in an object
; init ::= a ParenScript expression
; step ::= a ParenScript expression
; end-test ::= a ParenScript expression
+; result ::= a ParenScript expression
; body ::= a list of ParenScript statements
-;;; The `DO' form, which is similar to its Lisp form, is transformed
-;;; into a JavaScript `for' statement. Note that the ParenScript `DO'
-;;; form does not have a return value, that is because `for' is a
-;;; statement and not an expression in JavaScript.
+;;; All interation special forms are transformed into JavaScript `for'
+;;; statements and, if needed, lambda expressions.
+
+;;; `DO', `DO*', and `DOTIMES' carry the same semantics as their
+;;; Common Lisp equivalents.
+
+;;; `DO*' (note the variety of possible init-forms:
+
+(do* ((a) b (c (array "a" "b" "c" "d" "e"))
+ (d 0 (1+ d))
+ (e (aref c d) (aref c d)))
+ ((or (= d c.length) (eql e "x")))
+ (setf a d b e)
+ (document.write (+ "a: " a " b: " b "<br/>")))
+=> for (var a = null, b = null, c = ['a', 'b', 'c', 'd', 'e'], d = 0, e = c[d]; !(d == c.length || e == 'x'); d += 1, e = c[d]) {
+ a = d;
+ b = e;
+ document.write('a: ' + a + ' b: ' + b + '<br/>');
+ };
+
+;;; `DO' (note the parallel assignment):
(do ((i 0 (1+ i))
- (l (aref blorg i) (aref blorg i)))
- ((or (= i blorg.length)
- (eql l "Fumitastic")))
- (document.write (+ "L is " l)))
- => for (var i = 0, l = blorg[i];
- !(i == blorg.length || l == 'Fumitastic');
- i = i + 1, l = blorg[i]) {
- document.write('L is ' + l);
- }
-
-;;; The `DOTIMES' form, which lets a variable iterate from 0 upto an
-;;; end value, is a shortcut for `DO'.
-
-(dotimes (i blorg.length)
- (document.write (+ "L is " (aref blorg i))))
- => for (var i = 0; i < blorg.length; i = i + 1) {
- document.write('L is ' + blorg[i]);
- }
-
-;;; The `DOLIST' form is a shortcut for iterating over an array. Note
-;;; that this form creates temporary variables using a function called
-;;; `PS-GENSYM', which is similar to its Lisp counterpart `GENSYM'.
-
-(dolist (l blorg)
- (document.write (+ "L is " l)))
- => var tmpArr1 = blorg;
- for (var tmpI2 = 0; tmpI2 < tmpArr1.length;
- tmpI2 = tmpI2 + 1) {
- var l = tmpArr1[tmpI2];
- document.write('L is ' + l);
- };
-
-;;; The `DOEACH' form is converted to a `for (var .. in ..)' form in
-;;; JavaScript. It is used to iterate over the enumerable properties
-;;; of an object.
-
-(doeach (i object)
- (document.write (+ i " is " (aref object i))))
- => for (var i in object) {
- document.write(i + ' is ' + object[i]);
- }
+ (s 0 (+ s i (1+ i))))
+ ((> i 10))
+ (document.write (+ "i: " i " s: " s "<br/>")))
+=> var _js_i1 = 0;
+ var _js_s2 = 0;
+ var i = _js_i1;
+ var s = _js_s2;
+ delete _js_i1;
+ delete _js_s2;
+ for (; i <= 10; ) {
+ document.write('i: ' + i + ' s: ' + s + '<br/>');
+ var _js3 = i + 1;
+ var _js4 = s + i + (i + 1);
+ i = _js3;
+ s = _js4;
+ };
+
+;;; compare to `DO*':
+
+(do* ((i 0 (1+ i))
+ (s 0 (+ s i (1- i))))
+ ((> i 10))
+ (document.write (+ "i: " i " s: " s "<br/>")))
+=> for (var i = 0, s = 0; i <= 10; i += 1, s += i + (i - 1)) {
+ document.write('i: ' + i + ' s: ' + s + '<br/>');
+ };
+
+;;; `DOTIMES':
+
+(let* ((arr (array "a" "b" "c" "d" "e")))
+ (dotimes (i arr.length)
+ (document.write (+ "i: " i " arr[i]: " (aref arr i) "<br/>"))))
+=> var arr = ['a', 'b', 'c', 'd', 'e'];
+ for (var i = 0; i < arr.length; i += 1) {
+ document.write('i: ' + i + ' arr[i]: ' + arr[i] + '<br/>');
+ };
+
+;;; `DOTIMES' with return value:
+
+(let* ((res 0))
+ (alert (+ "Summation to 10 is "
+ (dotimes (i 10 res)
+ (incf res (1+ i))))))
+=> var res = 0;
+ alert('Summation to 10 is ' + (function () {
+ for (var i = 0; i < 10; i += 1) {
+ res += i + 1;
+ };
+ return res;
+ })());
+
+;;; `DOLIST' is like CL:DOLIST, but that it operates on numbered JS
+;;; arrays/vectors.
+
+(let* ((l (list 1 2 4 8 16 32)))
+ (dolist (c l)
+ (document.write (+ "c: " c "<br/>"))))
+=> var l = [1, 2, 4, 8, 16, 32];
+ for (var c = null, _js_arrvar2 = l, _js_idx1 = 0; _js_idx1 < _js_arrvar2.length; _js_idx1 += 1) {
+ c = _js_arrvar2[_js_idx1];
+ document.write('c: ' + c + '<br/>');
+ };
+
+(let* ((l (list 1 2 4 8 16 32))
+ (s 0))
+ (alert (+ "Sum of " l " is: "
+ (dolist (c l s)
+ (incf s c)))))
+=> var l = [1, 2, 4, 8, 16, 32];
+ var s = 0;
+ alert('Sum of ' + l + ' is: ' + (function () {
+ for (var c = null, _js_arrvar2 = l, _js_idx1 = 0; _js_idx1 < _js_arrvar2.length; _js_idx1 += 1) {
+ c = _js_arrvar2[_js_idx1];
+ s += c;
+ };
+ return s;
+ })());
+
+;;; `DOEACH' iterates across the enumerable properties of JS objects,
+;;; binding either simply the key of each slot, or alternatively, both
+;;; the key and the value.
+
+(let* ((obj (create :a 1 :b 2 :c 3)))
+ (doeach (i obj)
+ (document.write (+ i ": " (aref obj i) "<br/>"))))
+=> var obj = { a : 1, b : 2, c : 3 };
+ for (var i in obj) {
+ document.write(i + ': ' + obj[i] + '<br/>');
+ };
+
+(let* ((obj (create :a 1 :b 2 :c 3)))
+ (doeach ((k v) obj)
+ (document.write (+ k ": " v "<br/>"))))
+=> var obj = { a : 1, b : 2, c : 3 };
+ var v;
+ for (var k in obj) {
+ v = obj[k];
+ document.write(k + ': ' + v + '<br/>');
+ };
;;; The `WHILE' form is transformed to the JavaScript form `while',
;;; and loops until a termination test evaluates to false.
(while (film.is-not-finished)
(this.eat (new *popcorn)))
- => while (film.isNotFinished()) {
- this.eat(new Popcorn);
- }
+=> while (film.isNotFinished()) {
+ this.eat(new Popcorn);
+ }
;;;# The `CASE' statement
;;;t \index{CASE}
((1 "one") (alert "one"))
(2 (alert "two"))
(t (alert "default clause")))
- => switch (blorg[i]) {
- case 1:
- case 'one':
- alert('one');
- break;
- case 2:
- alert('two');
- break;
- default: alert('default clause');
+=> switch (blorg[i]) {
+ case 1:
+ case 'one':
+ alert('one');
+ break;
+ case 2:
+ alert('two');
+ break;
+ default:
+ alert('default clause');
}
; (SWITCH case-value clause*)
(1 (alert "If I get here"))
(2 (alert "I also get here"))
(default (alert "I always get here")))
- => switch (blorg[i]) {
- case 1: alert('If I get here');
- case 2: alert('I also get here');
- default: alert('I always get here');
- }
-
+=> switch (blorg[i]) {
+ case 1: alert('If I get here');
+ case 2: alert('I also get here');
+ default: alert('I always get here');
+ }
;;;# The `WITH' statement
;;;t \index{WITH}
(with (create :foo "foo" :i "i")
(alert (+ "i is now intermediary scoped: " i)))
- => with ({ foo : 'foo',
- i : 'i' }) {
- alert('i is now intermediary scoped: ' + i);
- }
+=> with ({ foo : 'foo', i : 'i' }) {
+ alert('i is now intermediary scoped: ' + i);
+ }
;;;# The `TRY' statement
;;;t \index{TRY}
(alert (+ "an error happened: " error)))
(:finally
(alert "Leaving the try form")))
- => try {
- throw 'i';
- } catch (error) {
- alert('an error happened: ' + error);
- } finally {
- alert('Leaving the try form');
- }
+=> try {
+ throw 'i';
+ } catch (error) {
+ alert('an error happened: ' + error);
+ } finally {
+ alert('Leaving the try form');
+ }
;;;# The HTML Generator
;;;t \index{PS-HTML}
;;; compiler. The resulting expression is a JavaScript expression.
(ps-html ((:a :href "foobar") "blorg"))
- => '<a href=\"foobar\">blorg</a>'
+=> '<A HREF=\"foobar\">blorg</A>'
(ps-html ((:a :href (generate-a-link)) "blorg"))
- => '<a href=\"' + generateALink() + '\">blorg</a>'
+=> '<A HREF=\"' + generateALink() + '\">blorg</A>'
;;; We can recursively call the ParenScript compiler in an HTML
;;; expression.
(document.write
(ps-html ((:a :href "#"
:onclick (lisp (ps-inline (transport)))) "link")))
- => document.write('<a href=\"#\" onclick=\"' + 'javascript:transport()' + '\">link</a>')
+=> document.write('<A HREF=\"#\" ONCLICK=\"' + 'javascript:transport()' + '\">link</A>')
;;; Forms may be used in attribute lists to conditionally generate
;;; the next attribute. In this example the textarea is sometimes disabled.
(setf element.inner-h-t-m-l
(ps-html ((:textarea (or disabled (not authorized)) :disabled "disabled")
"Edit me"))))
- => var disabled = null;
- var authorized = true;
- element.innerHTML =
- '<textarea'
- + (disabled || !authorized ? ' disabled=\"' + 'disabled' + '\"' : '')
- + '>Edit me</textarea>';
+=> var disabled = null;
+ var authorized = true;
+ element.innerHTML =
+ '<TEXTAREA'
+ + (disabled || !authorized ? ' DISABLED=\"' + 'disabled' + '\"' : '')
+ + '>Edit me</TEXTAREA>';
;;;# Macrology
;;;t \index{macro}
;;; of the `DOLIST' form (note how `PS-GENSYM', the ParenScript of
;;; `GENSYM', is used to generate new ParenScript variable names):
-(defpsmacro dolist (i-array &rest body)
- (let ((var (first i-array))
- (array (second i-array))
- (arrvar (ps-gensym "arr"))
- (idx (ps-gensym "i")))
- `(let* ((,arrvar ,array))
- (do ((,idx 0 (incf ,idx)))
- ((>= ,idx (slot-value ,arrvar 'length)))
- (let* ((,var (aref ,arrvar ,idx)))
- ,@body)))))
+(defpsmacro dolist ((var array &optional (result nil result?)) &body body)
+ (let ((idx (ps-gensym "_js_idx"))
+ (arrvar (ps-gensym "_js_arrvar")))
+ `(do* (,var
+ (,arrvar ,array)
+ (,idx 0 (1+ ,idx)))
+ ((>= ,idx (slot-value ,arrvar 'length))
+ ,@(when result? (list result)))
+ (setq ,var (aref ,arrvar ,idx))
+ ,@body)))
;;; Macros can be defined in ParenScript code itself (as opposed to
;;; from Lisp) by using the ParenScript `MACROLET' and `DEFMACRO'