Change dda-20110301-0dx by [email protected] on 2011-03-01 14:23:55 EST
in /Users/dda/laszlo/src/svn/openlaszlo/trunk-c/WEB-INF/lps/schema
for http://svn.openlaszlo.org/openlaszlo/trunk/WEB-INF/lps/schema
Summary: Eliminate the need for with(this) from most typical cases
New Features:
Bugs Fixed: LPP-8751 Eliminate the use of `with(this)`
Technical Reviewer: ptw (pending)
QA Reviewer: henry (pending)
Doc Reviewer: (pending)
Documentation:
Release Notes:
Overview:
[Mar 16 review - updated review comments indicated in [] brackets below]
with(this) can be eliminated from a function only when either of these
conditions occur:
- we have an complete knowledge of the class heirarchy.
- there are no free references in the function
and when this condition does not occur:
- another 'with(varname)' appears in the function.
We address the first condition via changes to the js2doc as it
generates the lfc schema, the tag compiler as it generates extra
'reference' JS classes that contain attributes and methods with
empty implementations, and the script compiler, as it uses the
reference classes to create a (usually) complete picture of the class
heirarchy for most cases. There's nothing we can do about the
second condition [a change from previously]. As for the third
condition, there are ways of mitigating it, but we don't bother for now
on the assumption that a function coded containing 'with(varname)' is not
a function that is coded for speed.
There may be some future work that may require a complete set of
reference classes, or method args, etc.. These are mentioned in
comments below as 'FUTURE WORK'. For most of these, preliminary
explorations were done, and abandoned for expediency.
Details:
[these 3 files changed since last review: added more tests]
test/lztest/lztest-class-impl.lzx:
test/smoke/smokecheck.lzx:
test/smoke/compiler.lzl:
Added some simple tests that illustrate how with(this) is inserted
in certain cases (before this change). By inspecting JS, used to
verify that 'this.' insertion and 'with(this)' removal is working.
Added more tests in response to Andre's testing, and suggestions by
Tucker [new]
Added tests using classes that inherit from LzURL, since it won't
be 'completely known', so will require with(this). [new]
WEB-INF/lps/schema/lfc-undeclared.lzx: [changed since last review, added
ondestroy, from LzEventable]
Added attribute: isinited, marked as private in doc, which is used
by old components, and cannot be marked as public.
Added method: setAttribute, which actually lives in LzEventable, and is
used quite often. We don't current emit reference classes for
any classes that are not associated with a tag (it was too hard
to get a non-tag class into the tag compiler - FUTURE WORK).
Added method: ondestroy, an event that really lives in LzEventable,
for the same reason as above. [new]
WEB-INF/lps/lfc/core/LzNode.lzs:
Added devnote about isinited.
WEB-INF/lps/lfc/compiler/Class.lzs:
Minor error message improvement that I found helpful once. (optional)
WEB-INF/lps/server/src/org/openlaszlo/js2doc/SchemaBuilder.java:
- jsname (the javascript name) for a class as well as jsextends
(the javascript class it extends) are put into the schema, though
not currently used - FUTURE WORK).
- omit event names not already defined as attributes
- method parameters are now collected and inserted into the schema,
but no typing is currently preserved (FUTURE WORK).
WEB-INF/lps/server/src/org/openlaszlo/compiler/ClassCompiler.java:
Ignore classes in the schema that has no associated tag name (FUTURE
WORK).
Small change to the protocol of compiling a ClassModel.
WEB-INF/lps/server/src/org/openlaszlo/compiler/NodeModel.java:
Ignore the jsname, jsextends parts of the schema (FUTURE WORK).
Small change to the protocol of compiling a ClassModel.
WEB-INF/lps/server/src/org/openlaszlo/compiler/ClassModel.java: [changed
since last review: fixed parenthesization, emit reference classes without
regard to runtime type]
- Changed isCompiled() to be true to its name.
- reworked compile() to handle emiting reference classes as needed.
- reworked emitClassDeclaration() to work with reference classes.
WEB-INF/lps/server/src/org/openlaszlo/sc/ScriptClass.java: [changed since
last review: elide, rather than rename, names that are reserved]
Changed generation of a class so it won't create attributes named 'with'
classes named 'class', etc. Needed when generating all classes for
the full schema (possibly optional now, but needed for FUTURE WORK).
WEB-INF/lps/server/src/org/openlaszlo/sc/CommonGenerator.java: [changed
since last review: renamed predefinedGlobals->globalProperties, added "canvas",
"escape", "unescape", removed "prototype"]
- rearrange globals and debugGlobals into separate sets, enumerate
the members of JS 'Object' class.
- ClassDescriptor.getInstanceProperties() modified to return an
'incomplete' set,
rather than null. ClassDescriptor.complete is set and needs to be
checked
by the caller.
- ClassDescriptor.incompleteSet() added for informational messages.
- ClassDescriptor.toString() for development/debugging.
- process reference classes minimally when needed at all.
WEB-INF/lps/server/src/org/openlaszlo/sc/JavascriptGenerator.java: [changed
since last review: renamed predefinedGlobals->globalProperties, new algorithm
for determining if withThis is needed]
- create set of forwardGlobals by doing a shallow walk of the AST.
- manage the 'possibleInstance' set to try to reduce it and move
as many items as appropriate/possible to the 'bindthis' set,
which is the set of variables we will actively bind to 'this'.
- issue warning if 'warnWithThis' or 'warnUnknownGlobals' is on.
WEB-INF/lps/server/src/org/openlaszlo/sc/SWF9Generator.java: [changed since
last review - fixed code to ignore reference classes]
Make sure reference classes are ignored in this generator.
WEB-INF/lps/server/src/org/openlaszlo/sc/DHTMLCompiler.java:
set option so that reference classes are accepted.
WEB-INF/lps/server/src/org/openlaszlo/sc/Compiler.java: [changed since last
review: added "warnUnknownGlobals"]
define 'referenceClass' pragma issued by tag compiler.
define 'registerReferenceClasses', an option only set by the
DHTMLCompiler.
define 'warnWithThis', a new debugging option that will warn
when with(this) is used, and give the reason behind it, e.g.:
'with(this) added in foobar: unknown parts of class hierarchy:
[LzTestManagerClass->LzEventable] and unaccounted refs: [LzHTTPLoader, escape]'
define 'warnUnknownGlobals', a new debugging option that will warn
when we know the inheritance chain, yet there are free references
that we cannot identify.
WEB-INF/lps/server/src/org/openlaszlo/sc/CodeGenerator.java:
Abide by new ClassDescriptor protocol
WEB-INF/lps/server/src/org/openlaszlo/sc/GenericVariableAnalyzer.java:
WEB-INF/lps/server/src/org/openlaszlo/sc/VariableAnalyzer.java:
WEB-INF/lps/server/src/org/openlaszlo/sc/WithThisAnalyzer.java:
Refactored VariableAnalyzer so essential parts could be shared
with a new 'WithThisAnalyzer'. The new analyzer walks the tree
and applies identifier --> this.identifier transformation for
any free variables found in a set. It also tracks if any
'with' constructs are found, which is a spoiler for with(this) removal.
WEB-INF/lps/server/sc/src/org/openlaszlo/sc/parser/SimpleNode.java:
Added indexOf() - a convenience function, helpful in the 'this binding'.
Tests:
- Ran smoketest (DHTML,SWF10) lztest, runlzunit (includes new tests)
- For lztest, spot checked to ensure that 'this.'
was inserted, specifically in the 'WithThis' tests
(in test/lztest/lztest-class-impl.lzx)
- Of the occurrences in lztest that require with(this), we know why they
occur: 1) LzTestManagerClass inherits
from LzEventable, not a class associated with a tag. This will not happen
for
pure lzx programs. 2) they often refer to use class names in the LFC:
LzHTTPLoader, LzTimeKernel. 3) they refer to identifiers 'canvas',
'escape'.
Files:
M test/lztest/lztest-class-impl.lzx
M test/smoke/smokecheck.lzx
M test/smoke/compiler.lzl
M WEB-INF/lps/schema/lfc-undeclared.lzx
M WEB-INF/lps/lfc/core/LzNode.lzs
M WEB-INF/lps/lfc/compiler/Class.lzs
M WEB-INF/lps/server/src/org/openlaszlo/js2doc/SchemaBuilder.java
A WEB-INF/lps/server/src/org/openlaszlo/sc/WithThisAnalyzer.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/JavascriptGenerator.java
A WEB-INF/lps/server/src/org/openlaszlo/sc/GenericVariableAnalyzer.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/VariableAnalyzer.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/CommonGenerator.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/SWF9Generator.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/DHTMLCompiler.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/Compiler.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/CodeGenerator.java
M WEB-INF/lps/server/src/org/openlaszlo/sc/ScriptClass.java
M WEB-INF/lps/server/src/org/openlaszlo/compiler/ClassCompiler.java
M WEB-INF/lps/server/src/org/openlaszlo/compiler/NodeModel.java
M WEB-INF/lps/server/src/org/openlaszlo/compiler/ClassModel.java
M WEB-INF/lps/server/sc/src/org/openlaszlo/sc/parser/SimpleNode.java
Changeset: http://svn.openlaszlo.org/openlaszlo/patches/dda-20110301-0dx.tar
--
Don Anderson
Java/C/C++, Berkeley DB, systems consultant
voice: 617-306-2057
email: [email protected]
www: http://www.ddanderson.com
blog: http://libdb.wordpress.com
