Revision history for JE

0.017   9 September, 2007
        Another alpha release, featuring just bug fixes:
        - Fixed a bug with the length property of strings being a Perl
          scalar instead of a JE::Number.
        - Fixed a bug that was causing line numbers in parse error
          messages to be counted from 1 even when another starting
          line number was given.
        -'continue' and 'break' statements now no longer clobber the
          return value of the previous statement, so
          eval('do{3; continue} while(0)') now returns 3, in accord-
          ance with the spec.
        - In a variable initialiser such as var a = b, the value is
          now correctly extracted from b and put inside a. Before, a
          reference to b would be put in a, such that
         'var a=non_existent_var; do_something_with(a)' would throw an
          error on the second statement, not the first.
        - Fixed a problem with 'continue OUTER' statements in nested
          loops calling the loop condition on the inner loop first.
          E.g., in the following snippet:
            var x = 0, y = 0
            OUTER: while(++x < 2) while(++y < 2) continue;
          The 'continue' would make '++y < 2' get evaluated, and then
         '++x < 2'; whereas only the latter should be evaluated. This
          problem was affecting do, while and for(;;) loops.
        - for(;;) loops now work when there is nothing before the
          first semicolon.
        - RegExp.prototype.exec now actually works (not fully tested)
          instead of always dying.
        - switch(non_existent_var) now dies as it should.
        - In a try-catch-finally statement, return, break and contin-
          ue statements and errors within the catch block no  longer
          prevent the final block from running.

0.016   22 July, 2007
        New feature:
        - Added support for filenames and line numbers in
          error messages.
        Bug fix:
        - Added a workaround for a perl 5.8.x bug (#24254) that was
          causing errors thrown from  expressions  within  argument
          lists to trigger an  "Attempt to  free  unreferenced  sca-
          lar" warning.

0.015   10 June, 2007
        - JS properties can now be bound to Perl subroutines that
          store/fetch the value (see JE::Types).
        - Class bindings now support binding of properties, as well
          as methods.
        - The constructor_name argument to bind_class is gone, since
          it was confusing.
        - bind_class now will understand 'package' to be the same as
         'name' if only the latter is provided.
        - bind_class now creates a constructor  whether  or  not  the
         'constructor' argument is passed. If it is not, the construc-
          tor that it makes will throw an error when invoked.
        - JE::Scope's get_var method has been renamed to find_var,
          since the name 'get_var' has the wrong implications.

0.014   30 May, 2007
        Features and API changes:
        - Binding of Perl classes to JE with the new bind_class method
        - JE::Parser's delete_statement method now takes mul-
          tiple args.
        Bug fixes:
        - JS's eval function now uses the same parser if called from
          code that was parsed with a custom parser.
        - JE::Object's prop({...}) method used to infer  'dontenum =>
          0' even if the property already existed.  Now it leaves the
          enumerability of existing properties alone if 'dontenum' is
          not specified explicitly.
        - Fixed a problem with bus errors resulting from  'autoload'
          handlers executing JS code when called from a tie handler
        - The & ^ | operators now work correctly when the second oper-
          and is outside the signed 32-bit range.

0.013   20 May, 2007
        Features and API changes:
        - JavaScript properties can now be autoloaded.
        - &JE::Scope::var has been renamed to &JE::Scope::get_var,
          since it was too easily confused with JavaScript's 'var'
          keyword, which does something different.
        - Started work on parser customisation
        Bug fixes:
        - '==' and '!=' were not correctly determining which type of
           comparison to do  when  the  two  operands  were  of  dif-
           ferent types.
        -  throw now requires an expression, as it always should
           have done.

0.012   13 May, 2007
        Yes, another alpha release.
        - JE::Object::Array's array dereference handler now returns a
          tied array.
        - JE::Object::Array's 'value' method now returns a copy of the
          object's internal array, instead of the array itself.
        - Functions created with new_function are now enumerable, just
          like 'alert', et al. in web browsers.
        Bug fixes:
        - Fixed the JE::Object's tie handlers so that  autovivification
          now works, and delete behaves the way it usually does in Perl.
        - When $obj->prop({ ... }) creates a new property and dontenum
          is not given, the property is now enumerable.
        - Corrected Array.prototype.unshift so that it resets the
          array's length.
        - JE::Object::Function's 'apply' method now upgrades the argu-
          ments to the function if the function is  written  in  Perl
          (version 0.011 only half-fixed the problem)

0.011   10 May, 2007
        Oh no! Another alpha release!
        - JE::Object::Function's 'apply' method now upgrades the argu-
          ments to the function
        - JE::Object's %{} overloading now returns a tied hash that
          can be used to modify the object  (untested and  still  a
          bit buggy).

0.010   9 May, 2007
        Added three features:
        - &{} overloading for JE::Object::Function
        - numeric overloading for JE::Object
        - 'exists' method for JE::Object and JE::Object::Array
        One bug fix:
        - JE::Object::Array's is_enum now correctly returns false for
          the length property

0.009   8 May, 2007
        Yet another alpha release. Here are the usual lists:
        New features/API changes:
        - Added numeric overloading to JE::Null.
        - Added compile as an alias for parse.
        - Added the 'exists' and 'class' methods to JE::Number
        Fixes:
        - JE::LValue's overloading was very buggy with anything other
          than  simple  conversion.  I've  fixed  it  and  written  a
          test script.
        - Corrected the bitshift operators such that numbers > 31 for
          the right operand now have % 32 applied, and are no  longer
          simply treated as 31.
        - Corrected JE::Null->to_boolean so it returns a JE::Boolean,
          not a JE::String.
        - Stopped surrogate escape sequences in string literals from
          producing warnings.
        - Corrected JE::Number's stringification overloading to match
          the stringification in JavaScript  (for NaN  and  Infinity)
        - A JE::Number that has a value of NaN now boolifies in  Perl
          as false, as in JavaScript.
        - Fixed the constructors for the various subclasses of Error,
          so that they no longer throw TypeErrors when called  ('new
          TypeError'  would actually cause the whole script to  die)
        - Corrected 'instanceof'  so it throws an error if its right
          operand is an object but not a function
        - Corrected the  'prototype'  properties of the various sub-
          classes of Error such that they now actually inherit from
          Error.prototype instead of directly from Object.prototype.
        - Fixed the << operator so it now works correctly on
          64-bit machines

0.008   22 April, 2007
        New features and API changes in this release:
        - Added JE::LValue's can method
        - new_function has been moved from JE to JE::Object, to make
          it more versatile
        - new_method has been written as a method of JE::Object
        - Changed the interface of JE::Code's 'execute' method, so that
          the third arg has three possible values  for  indicating  the
          type of code, and is no longer a boolean
        - Changed the delete method of JS values to support a second
          arg (see JE::Types)
        - Renamed the 'props' method to 'keys'
        - Renamed JE::compile to JE::parse
        - Added the 'exists' and 'class' methods to JE::Boolean
        - Added numification overloading to JE::Boolean
        Bug fixes:
        - Fixed the ~ operator so it works on 64-bit platforms
        - Changed most calls to 'UNIVERSAL::isa($thing, UNIVERSAL)' to
         'defined Scalar::Util::blessed $thing', since the former also 
          works with strings containing package names  (and  does  not
          necessarily tell whether something is blessed). This bug was
          causing strange errors.
        - Fixed a bug that was making errors thrown by JS  functions
          called from within JavaScript cause lots of warnings and a
          nonsensical ReferenceError.
        - String.prototype.substring now works instead of
          always dying.
        - function and var declarations now work in else blocks and
          labelled statements
        - continue <label> now works within a labelled switch or iter-
          ation statement
        - JS functions now return undefined when there is no  explicit
         'return'  statement.  Before,  the return value of  the  last
          statement that returned one was being  used,  as  with  JS's
         'eval' function (oops!). This required changing the interface
          of JE::Code slightly.
        - function declarations now clobber attributes of
          existing vars
        - Code run by JS's eval now inherits the scope chain from the
          caller (before, it was getting its own,  just like the body
          of a JS function)
        - var declarations no longer make existing vars undeletable
        - JE::Scope::new_var now looks for the first  object  in  the
          scope chain that is a call object (it used to use the first
          object, whatever it was)
        - Calling an lvalue that has a call (activation) object as its
          base object now works instead of just dying.
        - arguments.length is now a number, not a string
        - arguments objects are no longer given extra properties  cor-
          responding to the function's parameters if there aren't that
          many args.
        - Functions written in Perl that return  an  empty  list  now
          return 'undefined' to JS, instead of producing lots of warn-
          ings and dying.  In fact, they are called in scalar context
          now, rather than list context.
        - Fixed array literals so that elided elements do not exist.
          (Before, they would exist, but still be undefined.)
        - Fixed the bug that was causing isNaN to fail on OpenBSD.
        - Corrected the comma, assignment, conditional (? :), || and
          && operators so they no longer return lvalues.
        - Function.prototype.apply now puts its error in $@ when it
          dies. It used to leave $@ empty. It no longer dies when
          called with just one argument.
        - Fixed Array.prototype.toString and Array.prototype.
          toLocaleString such that they produce a sensible error mes-
          sage when invoked upon an object other than an array, rather
          than the nonsensical 'Can't locate object method "prop" via
          package "Object is not an Array"'
        - String.prototype.split now actually works.
        - JE::Code::parse now  stringifies  its  input,  avoiding  the
          potential problem of pos() being unreliable on a stringified
          object,  and solving the problem with  $obj =~ /(...)/  man-
          gling $1 in perl 5.8.5.

0.007   April Fool's Day, 2007
	Alpha release. New features/fixes:
        - Added the RegExp constructor and RegExp.prototype.exec
        - Added the rest of the string methods
        - Added the Boolean, Number and ReferenceError classes
        - Added the Math object
        - Fixed 'return' without an argument, so it returns undefined,
          rather than a null Perl string  (which  was  causing  weird
          errors elsewhere).
        - 'break' called from within a labelled statement was produc-
          ing warnings (fixed)
        - 'throw' without an argument now throws undefined, rather
          than 'Died at /usr/local/lib/perl5/5.8.8/JE/Code.pm
          line 387'
        - 'continue' now works with a do-while loop
        - instanceof now works instead of just dying
        - Assigning to a writeable property used  to  overwrite  the 
          dontenum attribute and make the property enumerable (fixed)
        - Fixed lvalues such that 'null.var = val' no longer creates a
          global property.  'null.var'  in void context now  throws  a
          TypeError.
        - Fixed the null and undefined classes, so they don't try to
          rebless the same scalar as each other.
        - Fixed the boolean class's to_string method, so it no longer
          gives 'true' for false and 'false' for true (!).

0.006   29 March, 2007
        Alpha release.
        - Added TypeError and RangeError classes
        - Finished the Function and Array classes (except for
          Function.prototype.toString)
        - JE::String now has an exportable 'surrogify' function
        - Added some methods (toString, valueOf, charAt, charCodeAt,
          concat, indexOf, lastIndexOf,  localeCompare)  to  String
          objects, and added the String constructor to the
          global object
        - Found and fixed quite a few bugs in the parser:
          o || && were parsing as | |  and & &
          o Hexadecimal literals would cause syntax errors
          o The parser would create a garbage tree when certain infix
            ops were followed by compound expressions that could  con-
            tain the same op (i.e., [], {}, () and function literals).
            (I fell into the 'sub foo { /regex(.*)/; foo(); print $1}'
            trap.)
          o Bracketed subscripts did not allow whitespace before the
            closing bracket
          o "a++\nb++"  without a semicolon between the two statements
            was causing a syntax error because -- and ++ were gobbling
            up trailing whitespace.
          o <<= and >>= and >>>= were causing syntax errors
          o for loops with variable declarations in the header
            weren't parsing
          o continue/throw/break/return were not parsing correctly
            when followed by a line break
          o 'with' was parsing as 'while' (!)
          o switch and try blocks weren't parsing correctly

0.005   5 March, 2007
        Alpha release. Changes and additions:
        - The parser has been rewritten completely with recursive sub-
          routines.  It is now faster than before,  and doesn't cause
          bus errors.
        - The Error and SyntaxError classes now actually work. Before
          I just threw them together without even testing them.
        - The Object constructor is now according to spec.
	- URI-handling functions and the URIError class
        - Added the rest of Object.prototype's properties

0.004   19 February, 2007
        Alpha release. New features and bug fixes in this
        release include:
        - Support for all JavaScript statements, not just expression
          statements
        - JE::String now provides a desurrogify function.
        - JE::upgrade now supports coderefs and makes '0' into a num-
          ber, as the docs say it does.
        - The JE::new_function method has been added.
        - Overloading for JE::LValue objects
        - JE::Object::props now returns the names of the object's pro-
          totype's properties as well as the object's own
        - Error and SyntaxError classes
        - Function literals and declarations
        - '==' in JS now does string comparison if at least one oper-
          and is a string  (it used to determine that it  should  do
          string  comparison  and  then  do  numeric  equals  anyway,
          because I typed '==' by mistake instead of 'eq'!)

0.003   14 February, 2007
        Alpha release. All JavaScript operators are now supported. JS
        numbers now use Perl's nan and inf.  A few bugs in the object
        classes have been fixed.  A bug preventing the  expansion  of
        backslash escapes in string literals has been fixed.

0.002   7 February, 2007
        Still a pre-alpha version with almost no features and lots of
        bugs. A lot of work has been done on the object classes.  The
        parser is half-written,  but the code that actually  executes
        the parse tree is far from complete.  The only really noticea-
        ble new features are that array and object literals and  iden-
        tifiers are now parsed and interpreted.

0.001   24 January, 2007
        Pre-alpha version,  with almost no features and lots of  bugs.
        The man pages describe many features that have not been imple-
        mented, so it's all just talk.

