scala.reflect.macros.TypecheckException
Represents mode of operations of the typechecker underlying c.typecheck
calls.
Represents mode of operations of the typechecker underlying c.typecheck
calls.
Is necessary since the shape of the typechecked tree alone is not enough to guess how it should be typechecked.
Can be EXPRmode (typecheck as a term), TYPEmode (typecheck as a type) or PATTERNmode (typecheck as a pattern).
Indicates that an argument to c.typecheck
should be typechecked as a pattern.
Indicates that an argument to c.typecheck
should be typechecked as a term.
Indicates that an argument to c.typecheck
should be typechecked as a term.
This is the default typechecking mode in Scala 2.11 and the only one supported in Scala 2.10.
Indicates that an argument to c.typecheck
should be typechecked as a type.
Infers an implicit value of the expected type pt
in the macro callsite context.
Infers an implicit value of the expected type pt
in the macro callsite context.
Optional pos
parameter provides a position that will be associated with the implicit search.
If silent
is false, TypecheckException
will be thrown in case of an inference error.
If silent
is true, the typecheck is silent and will return EmptyTree
if an error occurs.
Such errors don't vanish and can be inspected by turning on -Xlog-implicits.
Unlike in typecheck
, silent
is true by default.
Infers an implicit view from the provided tree tree
of the type from
to the type to
in the macro callsite context.
Infers an implicit view from the provided tree tree
of the type from
to the type to
in the macro callsite context.
Optional pos
parameter provides a position that will be associated with the implicit search.
If silent
is false, TypecheckException
will be thrown in case of an inference error.
If silent
is true, the typecheck is silent and will return EmptyTree
if an error occurs.
Such errors don't vanish and can be inspected by turning on -Xlog-implicits.
Unlike in typecheck
, silent
is true by default.
Contexts that represent macros in-flight, including the current one.
Contexts that represent macros in-flight, including the current one. Very much like a stack trace, but for macros only. Can be useful for interoperating with other macros and for imposing compiler-friendly limits on macro expansion.
Is also priceless for emitting sane error messages for macros that are called by other macros on synthetic (i.e. position-less) trees.
In that dire case navigate the openMacros
stack, and it will most likely contain at least one macro with a position-ful macro application.
See enclosingPosition
for a default implementation of this logic.
Unlike enclosingMacros
, this is a def, which means that it gets recalculated on every invocation,
so it might change depending on what is going on during macro expansion.
Typechecks the provided tree against the expected type pt
in the macro callsite context
under typechecking mode specified in mode
with EXPRmode being default.
Typechecks the provided tree against the expected type pt
in the macro callsite context
under typechecking mode specified in mode
with EXPRmode being default.
This populates symbols and types of the tree and possibly transforms it to reflect certain desugarings.
If silent
is false, TypecheckException
will be thrown in case of a typecheck error.
If silent
is true, the typecheck is silent and will return EmptyTree
if an error occurs.
Such errors don't vanish and can be inspected by turning on -Ymacro-debug-verbose.
Unlike in inferImplicitValue
and inferImplicitView
, silent
is false by default.
Typechecking can be steered with the following optional parameters:
withImplicitViewsDisabled
recursively prohibits implicit views (though, implicit vals will still be looked up and filled in), default value is false
withMacrosDisabled
recursively prohibits macro expansions and macro-based implicits, default value is false
In the current implementation of Scala's reflection API, untyped trees (also known as parser trees or unattributed trees) are observationally different from typed trees (also known as typer trees, typechecked trees or attributed trees),
In the current implementation of Scala's reflection API, untyped trees (also known as parser trees or unattributed trees) are observationally different from typed trees (also known as typer trees, typechecked trees or attributed trees),
Usually, if some compiler API takes a tree, then both untyped and typed trees will do. However in some cases,
only untyped or only typed trees are appropriate. For example, eval only accepts untyped trees and one can only splice
typed trees inside typed trees. Therefore in the current reflection API, there is a need in functions
that go back and forth between untyped and typed trees. For this we have typecheck and untypecheck
.
Note that untypecheck
is currently afflicted by https://issues.scala-lang.org/browse/SI-5464,
which makes it sometimes corrupt trees so that they don't make sense anymore. Unfortunately, there's no workaround for that.
We plan to fix this issue soon, but for now please keep it in mind.
Recursively resets locally defined symbols and types in a given tree.
Recursively resets locally defined symbols and types in a given tree. WARNING: Don't use this API, go for untypecheck instead.
(Since version 2.11.0) Use c.untypecheck
instead
Test two objects for inequality.
Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types and null
.
Equivalent to x.hashCode
except for boxed numeric types and null
.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null
returns a hashcode where null.hashCode
throws a
NullPointerException
.
a hash value consistent with ==
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
scala.reflect.macros.TypecheckException
Cast the receiver object to be of type T0
.
Cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String]
will throw a ClassCastException
at
runtime, while the expression List(1).asInstanceOf[List[String]]
will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
not specified by SLS as a member of AnyRef
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
The eq
method implements an equivalence relation on
non-null instances of AnyRef
, and has three additional properties:
x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.null.eq(null)
returns true
. When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
true
if the argument is a reference to the receiver object; false
otherwise.
The equality method for reference types.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize
method is invoked, as
well as the interaction between finalize
and non-local returns
and exceptions, are all platform dependent.
not specified by SLS as a member of AnyRef
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
Test whether the dynamic type of the receiver object is T0
.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String]
will return false
, while the
expression List(1).isInstanceOf[List[String]]
will return true
.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Equivalent to !(this eq that)
.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
(Since version 2.11.0) Use c.typecheck
instead
Typers.typecheck
EXPERIMENTAL
A slice of the Scala macros context that partially exposes the type checker to macro writers.