TypedTreeInfo

Extractor for not-null assertions. A not-null assertion for reference x has the form x.$asInstanceOf$[x.type & T].

Extractors for quotes

Extractors for splices

Extractors for type splices

An extractor for closures, either contained in a block or standalone.

An extractor for def of a closure contained the block of the closure.

Fold f over all tree nodes, in depth-first, prefix order

Fold f over all tree nodes, in depth-first, prefix order, but don't visit subtrees where f returns a different result for the root, i.e. f(x, root) ne x.

A class for copying trees. The copy methods avoid creating a new tree If all arguments stay the same.

Note: Some of the copy methods take a context. These are exactly those methods that are overridden in TypedTreeCopier so that they selectively retype themselves. Retyping needs a context.

The type and term arguments of a possibly curried call, in the order they are given

If tree is a closure, its body, otherwise tree itself

(1) If tree is a constant expression, its value as a Literal, or tree itself otherwise.

Note: Demanding idempotency instead of purity in literalize is strictly speaking too loose. Example

object O { final val x = 42; println("43") } O.x

Strictly speaking we can't replace O.x with 42. But this would make most expressions non-constant. Maybe we can change the spec to accept this kind of eliding behavior. Or else enforce true purity in the compiler. The choice will be affected by what we will do with inline and with Singleton type bounds (see SIP 23). Presumably

object O1 { val x: Singleton = 42; println("43") } object O2 { inline val x = 42; println("43") }

should behave differently.

O1.x should have the same effect as { println("43"); 42 }

whereas

O2.x = 42

Revisit this issue once we have standardized on inline. Then we can demand purity of the prefix unless the selection goes to a inline val.

Note: This method should be applied to all term tree nodes that are not literals, that can be idempotent, and that can have constant types. So far, only nodes of the following classes qualify:

  Ident
  Select
  TypeApply

(2) A primitive unary operator expression pre.op where op is one of +, -, ~, ! that has a constant type ConstantType(v) but that is not a constant expression (i.e. pre has side-effects) is translated to

{ pre; v }

(3) An expression pre.getClass[..]() that has a constant type ConstantType(v) but where pre has side-effects is translated to:

{ pre; v }

This avoids the situation where we have a Select node that does not have a symbol.

Decompose a template body into parameters and other statements

Going from child to parent, the path of tree nodes that starts with a definition of symbol sym and ends with root, or Nil if no such path exists. Pre: sym must have a position.

If tree is a DefTree, the symbol defined by it, otherwise NoSymbol

The statement sequence that contains a definition of sym, or Nil if none was found. For a tree to be found, The symbol must have a position and its definition tree must be reachable from come tree stored in an enclosing context.

The purity level of this expression. See docs for PurityLevel for what that means

Note that purity and idempotency are treated differently. References to modules and lazy vals are impure (side-effecting) both because side-effecting code may be executed and because the first reference takes a different code path than all to follow; but they are idempotent because running the expression a second time gives the cached result.

The function part of a possibly curried call. Unlike methPart this one does not decompose blocks

Is this pattern node a catch-all or type-test pattern?

Is the application tree with function part fn known to be pure? Function value and arguments can still be impure.

Is tree a this node which belongs to enclClass?

Is this a (potentially applied) selection of a member of a structural type that is not a member of an underlying class or trait?

Is tree a reference to a mutable variable, or to a potential getter that has a setter in the same class?

The symbols defined locally in a statement list

Is symbol potentially a getter of a mutable variable?

The variables defined by a pattern, in reverse order of their appearance.

The qualifier part of a Select or Ident. For an Ident, this is the This of the current class.

The purity level of this reference.

The tree containing only the top-level classes and objects matching either cls or its companion object

Return a pair consisting of (supercall, rest)

• supercall: the superclass call, excluding trait constr calls

The supercall is always the first statement (if it exists)

The purity level of this statement.

Strips layers of .asInstanceOf[T] / _.$asInstanceOf[T]() from an expression

The term arguments of a possibly curried call

The top level classes in this tree, including only those module classes that are not a linked class of some other class in the result.

If tree is an instance of TupleN[...](e1, ..., eN), the arguments e1, ..., eN otherwise the empty list.

The type arguments of a possibly curried call

Delegate to FunProto or FunProtoTyped depending on whether the prefix is untpd or tpd.

All type and value parameter symbols of this DefDef

Construct the application $receiver.$method[$targs]($args) using overloading resolution to find a matching overload of $method if necessary. This is useful when overloading resolution needs to be performed in a phase after typer. Note that this will not perform any kind of implicit search.

The (last) list of arguments of an application

Does this CaseDef catch everything of a certain Type?

Does this CaseDef catch Throwable?

The first constructor definition in stats

Checks whether predicate p is true for all result parts of this expression, where we zoom into Ifs, Matches, and Blocks.

Does this list contain a named argument tree?

For untyped trees, this is just the identity. For typed trees, a context derived form ctx that records call as the innermost enclosing call for which the inlined version is currently processed.

Is tree a backquoted identifier or definition

Is this pattern node a catch-all (wildcard or variable) pattern?

Is this case guarded?

Is tree a path?

Is tpt a vararg type of the form T* or => T*?

Is tree a self constructor call this(...)? I.e. a call to a constructor of the same object?

Is tree a super constructor call?

Is this pattern node a synthetic catch-all case, added during PartialFuction synthesis before we know whether the user provided cases are exhaustive.

Is this parameter list a using clause?

Is tree a variable pattern?

Is the argument a wildcard argument of the form _ or x @ _?

Is this argument node of the form *, or is it a reference to such an argument ? The latter case can happen when an argument is lifted.

Does this argument list end with an argument of the form : _* ?

If tparams is non-empty, add it to the left paramss, merging it with a leading type parameter list of paramss, if one exists.

If path looks like a language import, Some(name) where name is experimental if that sub-module is imported, and the empty term name otherwise.

The context to use when mapping or accumulating over a tree

The method part of an application node, possibly enclosed in a block with only valdefs as statements. the reason for also considering blocks is that named arguments can transform a call into a block, e.g. (b = foo, a = bar) is transformed to { val x$1 = foo val x$2 = bar (x$2, x$1) }

The number of arguments in an application

The largest subset of {NoInits, PureInterface} that a trait or class with these parents can have as flags.

Hook to indicate that a transform of some subtree should be skipped

If this is an application, its function part, stripping all Apply nodes (but leaving TypeApply nodes in). Otherwise the tree itself.

If this is a block, its expression part

The underlying pattern ignoring any bindings