Bug 77360

Summary: [dom] API to get generic type from parametrized type binding
Product: [Eclipse Project] JDT Reporter: Martin Aeschlimann <martinae>
Component: CoreAssignee: Jerome Lanneluc <jerome_lanneluc>
Status: RESOLVED DUPLICATE QA Contact:
Severity: enhancement    
Priority: P3 CC: dirk_baeumer, markus.kell.r, Olivier_Thomann, tobias_widmer
Version: 3.0   
Target Milestone: 3.1 M4   
Hardware: PC   
OS: Windows XP   
Whiteboard:
Bug Depends on:    
Bug Blocks: 78183    

Description Martin Aeschlimann CLA 2004-11-01 07:02:15 EST 
20041101

In 1.5 we have now 3 'layers' of type bindings

a.) For a declaration List<T> what you get is a 'generic type' type binding.
binding.getMethods() would return you, amongst others, 'add(T)'.

b.) For a reference List<String> you get a 'parametrized type' type binding.
When asked for its methods you get methods like 'add(String)'

c.) A reference 'List' returns a raw type binding, returning a method 'add(Object)'

The current API of ITypeBinding doesn't make a difference between a. and b.
and also doesn't have API to go from b. to a. or even from a. to b.

What does exist are methods 'getErasure()' to get c. from a. and b. and
isRawType() to test for c.

In IMethodBinding there is the same problem
- add(T)
- add(List)
- add(Object)
Comment 1 Markus Keller CLA 2004-11-04 06:44:37 EST 
> What does exist are methods 'getErasure()' to get c. from a. and b. and
> isRawType() to test for c.

That's not exactly true in 200411022000. [Note: I use List<E> where Martin wrote
List<T>, since List<E> is used in jdk1.5 source.]

Calling getErasure() on source reference binding for 'List' (raw, c.) or
'List<String>' (parameterized, b.) yields List<E> (declaration, a.), whose
getTypeParameters() is {E} and whose isParameterizedType() and isRawType() both
return false.

getErasure() is a link a./b./c. ==> a.
Test for a.: isRawType() == false && isParameterizedType() == false
    [Test whether type is generic: getTypeParameters().length != 0]
Test for b.: isParameterizedType() == true
Test for c.: isRawType() == true

Missing links are
AB.)  a. ==> b.: List<E>, type argument 'String' ==> List<String>
AC.)  a. ==> c.: List<E> ==> List

Conversions b. ==> c. and c. ==> b. can be composed from getErasure() and AC.
and AB.
Comment 2 Philipe Mulet CLA 2004-11-09 12:26:18 EST 
Along the lines of making DOM AST more usable.
Comment 3 Martin Aeschlimann CLA 2004-11-23 13:35:41 EST 
I think this bug is mostly solved with the latest API additions

- isGenericType() marks a.)
- isParameterizedType() marks b.)
- isRawType() marks c.)

getErasure() gives a.) from b. and c.

Missing are methods for get b. or c. from a.) but that was an 'nice to have'
request and along the lines of bug 40096 (please reopen that one... :-))
Comment 4 Jerome Lanneluc CLA 2004-11-24 05:27:52 EST 
Martin, since this bug was entered, only isGenericType() was added. So I guess
this bug should have been a request for isGenericType(), right ?
Comment 5 Martin Aeschlimann CLA 2004-11-24 05:51:22 EST 
yes, isGenericType() was in fact the main request.
The rest is covered by bug 40096
Comment 6 Jerome Lanneluc CLA 2004-11-24 05:54:49 EST 
Thanks Martin. This is a dup of bug 78266 then.

*** This bug has been marked as a duplicate of 78266 ***