Mixin

class Mixin extends MiniPhase with SymTransformer

This phase performs the following transformations:

  1. (done in traitDefs and transformSym) For every concrete trait getter

    def x(): T = expr

make it non-private, and add the definition of its trait setter:

 <mods> def TraitName$_setter_$x(v: T): Unit
  1. (done in traitDefs) Make every concrete trait setter

    def x_=(y: T) = ()

deferred by mapping it to

<mods> def x_=(y: T)
  1. (done in transformSym) For every module class constructor in traits, remove its Private flag (but do not expand its name), since it will have to be instantiated in the classes that mix in the trait.

  2. For a non-trait class C:

    For every trait M directly implemented by the class (see SymUtils.mixin), in reverse linearization order, add the following definitions to C:

    4.1 (done in `traitInits`) For every parameter accessor `<mods> def x(): T` in M,
        in order of textual occurrence, add
    
         <mods> def x() = e
    
        where `e` is the constructor argument in C that corresponds to `x`. Issue
        an error if no such argument exists.
    
    4.2 (done in `traitInits`) For every concrete trait getter `<mods> def x(): T` in M
        which is not a parameter accessor, in order of textual occurrence, produce the following:
    
        4.2.1 If `x` is also a member of `C`, and is a lazy val,
    
          <mods> lazy val x: T = super[M].x
    
        4.2.2 If `x` is also a member of `C`, and is a module,
    
          <mods> lazy module val x: T = new T$(this)
    
        4.2.3 If `x` is also a member of `C`, and is something else:
    
          <mods> def x(): T = _
    
        4.2.5 If `x` is not a member of `C`, nothing gets added.
    
    4.3 (done in `superCallOpt`) The call:
    
          super[M].$init$()
    
    4.4 (done in `setters`) For every concrete setter `<mods> def x_=(y: T)` in M:
    
          <mods> def x_=(y: T) = ()
    
    4.5 (done in `mixinForwarders`) For every method
    `<mods> def f[Ts](ps1)...(psN): U` imn M` that needs to be disambiguated:
    
          <mods> def f[Ts](ps1)...(psN): U = super[M].f[Ts](ps1)...(psN)
    
    A method in M needs to be disambiguated if it is concrete, not overridden in C,
    and if it overrides another concrete method.
    
  3. (done in transformTemplate and transformSym) Drop all parameters from trait constructors, and rename them to nme.TRAIT_CONSTRUCTOR.

  4. (done in transformSym) Drop ParamAccessor flag from all parameter accessors in traits.

Conceptually, this is the second half of the previous mixin phase. It needs to run after erasure because it copies references to possibly private inner classes and objects into enclosing classes where they are not visible. This can only be done if all references are symbolic.

Companion:
object
class MiniPhase
class Phase
class Object
trait Matchable
class Any

Value members

Concrete methods

override def changesMembers: Boolean

Can this transform create or delete non-private members?

Can this transform create or delete non-private members?

Definition Classes
override def description: String
Definition Classes
override def phaseName: String

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
override def runsAfter: Set[String]

List of names of phases that should precede this phase

List of names of phases that should precede this phase

Definition Classes
override def transformSym(sym: SymDenotation)(using Context): SymDenotation
Definition Classes
override def transformTemplate(impl: Template)(using Context): Template
Definition Classes

Inherited methods

final def <=(that: Phase): Boolean
Inherited from:
Phase

If set, implicit search is enabled

If set, implicit search is enabled

Inherited from:
Phase

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 change the parents of a class?

Can this transform change the parents of a class?

Inherited from:
Phase
def checkPostCondition(tree: Tree)(using Context): Unit

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
Inherited from:
Phase
final def erasedTypes: Boolean
Inherited from:
Phase
Inherited from:
Phase
final def flatClasses: Boolean
Inherited from:
Phase
final def hasNext: Boolean
Inherited from:
Phase
def id: Int

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
Inherited from:
Phase

Output should be checkable by TreeChecker

Output should be checkable by TreeChecker

Inherited from:
Phase
Inherited from:
Phase
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
final def iterator: Iterator[Phase]
Inherited from:
Phase
Inherited from:
Phase
def lastPhaseId(using Context): Int

The last phase during which the transformed denotations are valid

The last phase during which the transformed denotations are valid

Inherited from:
DenotTransformer
final def monitor(doing: String)(body: => Unit)(using Context): Unit
Inherited from:
Phase
final def next: Phase
Inherited from:
Phase
Inherited from:
Phase
Inherited from:
Phase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForBind(tree: Bind)(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForIf(tree: If)(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForNew(tree: New)(using Context): Context
Inherited from:
MiniPhase
def prepareForOther(tree: Tree)(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForStats(trees: List[Tree])(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForThis(tree: This)(using Context): Context
Inherited from:
MiniPhase
def prepareForTry(tree: Try)(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def prepareForUnit(tree: Tree)(using Context): Context
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
final def prev: Phase
Inherited from:
Phase
final def refChecked: Boolean
Inherited from:
Phase
final override def relaxedTyping: Boolean

If set, allow missing or superfluous arguments in applications and type applications.

If set, allow missing or superfluous arguments in applications and type applications.

Definition Classes
Inherited from:
MiniPhase
override def run(using Context): Unit
Definition Classes
Inherited from:
MiniPhase
Inherited from:
Phase

List of names of phases that should have finished their processing of all compilation units before this phase starts

List of names of phases that should have finished their processing of all compilation units before this phase starts

Inherited from:
MiniPhase
Inherited from:
Phase
Inherited from:
Phase
Inherited from:
Phase
protected def singletonGroup: MegaPhase
Inherited from:
MiniPhase
def start: Int
Inherited from:
Phase
override def toString: String

Returns a string representation of the object.

Returns a string representation of the object.

The default representation is platform dependent.

Returns:

a string representation of the object.

Definition Classes
Phase -> Any
Inherited from:
Phase

The transformation method

The transformation method

Inherited from:
SymTransformer
def transformAllDeep(tree: Tree)(using Context): Tree

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
Inherited from:
MiniPhase
def transformApply(tree: Apply)(using Context): Tree
Inherited from:
MiniPhase
def transformAssign(tree: Assign)(using Context): Tree
Inherited from:
MiniPhase
def transformBind(tree: Bind)(using Context): Tree
Inherited from:
MiniPhase
def transformBlock(tree: Block)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformDefDef(tree: DefDef)(using Context): Tree
Inherited from:
MiniPhase
def transformFollowing(tree: Tree)(using Context): Tree

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
def transformIdent(tree: Ident)(using Context): Tree
Inherited from:
MiniPhase
def transformIf(tree: If)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformMatch(tree: Match)(using Context): Tree
Inherited from:
MiniPhase
def transformNew(tree: New)(using Context): Tree
Inherited from:
MiniPhase
def transformOther(tree: Tree)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformReturn(tree: Return)(using Context): Tree
Inherited from:
MiniPhase
def transformSelect(tree: Select)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformStats(trees: List[Tree])(using Context): List[Tree]
Inherited from:
MiniPhase
def transformSuper(tree: Super)(using Context): Tree
Inherited from:
MiniPhase
def transformThis(tree: This)(using Context): Tree
Inherited from:
MiniPhase
def transformTry(tree: Try)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformTyped(tree: Typed)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def transformUnit(tree: Tree)(using Context): Tree
Inherited from:
MiniPhase
def transformValDef(tree: ValDef)(using Context): Tree
Inherited from:
MiniPhase
Inherited from:
MiniPhase
def validFor(using Context): Period

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

Inherited fields

Inherited from:
MiniPhase