[Laszlo-dev] For Review: Change 20080107-ptw-n Summary: Implement `is` operator

[P T Withington]

Change 20080107-ptw-n by ptw at dueling-banjos.local on 2008-01-07  
15:41:52 EST
     in /Users/ptw/OpenLaszlo/ringding-2
     for http://svn.openlaszlo.org/openlaszlo/trunk

Summary: Implement `is` operator

Bugs Fixed:
LPP-3632 'Implement `is` operator'

Technical Reviewer: dda at ddanderson.com (pending)
QA Reviewer: henry.minsky at gmail.com (pending)
Doc Reviewer: lou at louiorio.com (pending)

Documentation:
We now implement the ECMAScript 4 `is` operator

Details:
     lztest-class-impl: Use modern syntax, verify that `is` is
     equivalent to `instanceof` and works properly for mixins.

     Class: add runtime support for `is` operator on mixins

     JavascriptGenerator, CodeGenerator, ParseTreePrinter, Parser:  Add
     support for `is` operator, which in JS1 runtimes is approximated
     as:  a is b => b['$lzsc$isa'] ? b.$lzsc$isa(a) : (a instanceof b),
     relying on the runtime support in Class for $lzsc$isa.

     ASTVisitor: remove the unused visitBinaryExpression

Tests:
     Amended class-impl test to test that `is` is equivalent to
     `instanceof` for classes and works properly for mixins.

Files:
M      test/lztest/lztest-class-impl.lzx
M      WEB-INF/lps/lfc/compiler/Class.lzs
M      WEB-INF/lps/server/src/org/openlaszlo/sc/JavascriptGenerator.java
M      WEB-INF/lps/server/src/org/openlaszlo/sc/ASTVisitor.java
M      WEB-INF/lps/server/src/org/openlaszlo/sc/CodeGenerator.java
M      WEB-INF/lps/server/src/org/openlaszlo/sc/ParseTreePrinter.java
M      WEB-INF/lps/server/sc/src/org/openlaszlo/sc/Parser.jjt

Changeset: http://svn.openlaszlo.org/openlaszlo/patches/20080107-ptw-n.tar