This phase performs the necessary rewritings to eliminate classes and methods nested in other methods. In detail:
- It adds all free variables of local functions as additional parameters (proxies).
- It rebinds references to free variables to the corresponding proxies,
- It lifts all local functions and classes out as far as possible, but at least to the enclosing class.
- It stores free variables of non-trait classes as additional fields of the class. The fields serve as proxies for methods in the class, which avoids the need of passing additional parameters to these methods.
A particularly tricky case are local traits. These cannot store free variables as field proxies, because LambdaLift runs after Mixin, so the fields cannot be expanded anymore. Instead, methods of local traits get free variables of the trait as additional proxy parameters. The difference between local classes and local traits is illustrated by the two rewritings below.
def f(x: Int) = { def f(x: Int) = new C(x).f2 class C { ==> class C(x$1: Int) { def f2 = x def f2 = x$1 } } new C().f2 }
def f(x: Int) = { def f(x: Int) = new C().f2(x) trait T { ==> trait T def f2 = x def f2(x$1: Int) = x$1 } } class C extends T class C extends T new C().f2 }
- Companion:
- object
Value members
Concrete methods
A name given to the Phase that can be used to debug the compiler. For
instance, it is possible to print trees after a given phase using:
A name given to the Phase that can be used to debug the compiler. For
instance, it is possible to print trees after a given phase using:
$ ./bin/scalac -Xprint:<phaseNameHere> sourceFile.scala
- Definition Classes
If set, use relaxed typing for all phases in group
If set, use relaxed typing for all phases in group
- Definition Classes
Inherited methods
Can this transform change the base types of a type?
Can this transform change the base types of a type?
- Inherited from:
- Phase
Can this transform create or delete non-private members?
Can this transform create or delete non-private members?
- Inherited from:
- Phase
Can this transform change the parents of a class?
Can this transform change the parents of a class?
- Inherited from:
- Phase
Check what the phase achieves, to be called at any point after it is finished.
Check what the phase achieves, to be called at any point after it is finished.
- Inherited from:
- Phase
The sequence position of this phase in the given context where 0 is reserved for NoPhase and the first real phase is at position 1. -1 if the phase is not installed in the context.
The sequence position of this phase in the given context where 0 is reserved for NoPhase and the first real phase is at position 1. -1 if the phase is not installed in the context.
- Inherited from:
- Phase
Output should be checkable by TreeChecker
Output should be checkable by TreeChecker
- Inherited from:
- Phase
Is this phase the standard typerphase? True for TyperPhase, but not for other first phases (such as FromTasty or Parser). The predicate is tested in some places that perform checks and corrections. It's different from ctx.isAfterTyper (and cheaper to test).
Is this phase the standard typerphase? True for TyperPhase, but not for other first phases (such as FromTasty or Parser). The predicate is tested in some places that perform checks and corrections. It's different from ctx.isAfterTyper (and cheaper to test).
- Inherited from:
- Phase
The last phase during which the transformed denotations are valid
The last phase during which the transformed denotations are valid
- Inherited from:
- DenotTransformer
List of names of phases that should precede this phase
List of names of phases that should precede this phase
- Inherited from:
- Phase
Transform tree using all transforms of current group (including this one)
Transform tree using all transforms of current group (including this one)
- Inherited from:
- MiniPhase
Transform single node using all transforms following the current one in this group
Transform single node using all transforms following the current one in this group
- Inherited from:
- MiniPhase
Transform tree using all transforms following the current one in this group
Transform tree using all transforms following the current one in this group
- Inherited from:
- MiniPhase
The validity period of the transformed denotations in the given context
The validity period of the transformed denotations in the given context
- Inherited from:
- DenotTransformer