Scala 3/scala.quoted/Quotes

Quotes

trait Quotes

Quotation context provided by a macro expansion or in the scope of scala.quoted.staging.run. Used to perform all operations on quoted Expr or Type.

It contains the low-level Typed AST API metaprogramming API. This API does not have the static type guarantees that Expr and Type provide.

Source
Quotes.scala
class Object
trait Matchable
class Any

Type members

Classlikes

trait reflectModule

Low-level Typed AST metaprogramming API.

Low-level Typed AST metaprogramming API.

Provides all functionality related to AST-based metaprogramming.

Each type XYZ in the API is defined as an abstract type type XYZ. Methods on XYZ are provided by a given XYZMethods which implements extension methods on XYZ in the trait XYZMethods. The XYZ module is defined by a val XYZ: XYZModule which contains the methods defined in XYZModule. Type tests (TypeTest) are also given to perform subtype checks on these types.

Type hierarchy


+- Tree -+- PackageClause
         |
         +- Statement -+- Import
         |             +- Export
         |             +- Definition --+- ClassDef
         |             |               +- TypeDef
         |             |               +- DefDef
         |             |               +- ValDef
         |             |
         |             +- Term --------+- Ref -+- Ident
         |                             |       +- Select
         |                             |
         |                             +- Literal
         |                             +- This
         |                             +- New
         |                             +- NamedArg
         |                             +- Apply
         |                             +- TypeApply
         |                             +- Super
         |                             +- Typed
         |                             +- Assign
         |                             +- Block
         |                             +- Closure
         |                             +- If
         |                             +- Match
         |                             +- SummonFrom
         |                             +- Try
         |                             +- Return
         |                             +- Repeated
         |                             +- Inlined
         |                             +- SelectOuter
         |                             +- While
         |
         |
         +- TypeTree ----+- Inferred
         |               +- TypeIdent
         |               +- TypeSelect
         |               +- TypeProjection
         |               +- Singleton
         |               +- Refined
         |               +- Applied
         |               +- Annotated
         |               +- MatchTypeTree
         |               +- ByName
         |               +- LambdaTypeTree
         |               +- TypeBind
         |               +- TypeBlock
         |
         +- TypeBoundsTree
         +- WildcardTypeTree
         |
         +- CaseDef
         |
         +- TypeCaseDef
         +- Bind
         +- Unapply
         +- Alternatives

+- ParamClause -+- TypeParamClause
                +- TermParamClause

+- TypeRepr -+- NamedType -+- TermRef
             |             +- TypeRef
             +- ConstantType
             +- SuperType
             +- Refinement
             +- AppliedType
             +- AnnotatedType
             +- AndOrType -+- AndType
             |             +- OrType
             +- MatchType
             +- ByNameType
             +- ParamRef
             +- ThisType
             +- RecursiveThis
             +- RecursiveType
             +- LambdaType -+- MethodOrPoly -+- MethodType
             |              |                +- PolyType
             |              +- TypeLambda
             +- MatchCase
             +- TypeBounds
             +- NoPrefix

+- Selector -+- SimpleSelector
             +- RenameSelector
             +- OmitSelector
             +- GivenSelector

+- Signature

+- Position

+- SourceFile

+- Constant -+- BooleanConstant
             +- ByteConstant
             +- ShortConstant
             +- IntConstant
             +- LongConstant
             +- FloatConstant
             +- DoubleConstant
             +- CharConstant
             +- StringConstant
             +- UnitConstant
             +- NullConstant
             +- ClassOfConstant
+- Symbol

+- Flags
Source
Quotes.scala

Types

type Nested = Quotes

Type of a Quotes provided by a splice within a quote that took this context.

Type of a Quotes provided by a splice within a quote that took this context.

Source
Quotes.scala

Value members

Abstract fields

val reflect: reflectModule

Low-level Typed AST metaprogramming API.

Low-level Typed AST metaprogramming API.

Provides all functionality related to AST-based metaprogramming.

Usage:

import scala.quoted._
def f(expr: Expr[Int])(using Quotes) =
  import quotes.reflect._
  val ast: Term = expr.asTerm
  ...



See reflectModule for full API.


Source
Quotes.scala
Extensions
Extensions
extension (self: Expr[Any])
 def asExprOf(using Type[X]): Expr[X]
Convert this to an quoted.Expr[X] if this expression is a valid expression of type X or throws
Convert this to an quoted.Expr[X] if this expression is a valid expression of type X or throws
Source
Quotes.scala
 def isExprOf(using Type[X]): Boolean
Checks is the quoted.Expr[?] is valid expression of type X
Checks is the quoted.Expr[?] is valid expression of type X
Source
Quotes.scala
extension (self: Expr[T])
 def matches[T](that: Expr[Any]): Boolean
Pattern matches this against that. Effectively performing a deep equality check.
It does the equivalent of


Pattern matches this against that. Effectively performing a deep equality check.
It does the equivalent of


this match
  case '{...} => true // where the contents of the pattern are the contents of `that`
  case _ => false



Source
Quotes.scala
 def show[T]: String
Show a source code like representation of this expression
Show a source code like representation of this expression
Source
Quotes.scala
 def value[T](using FromExpr[T]): Option[T]
Return the value of this expression.
Return the value of this expression.
Returns None if the expression does not represent a value or possibly contains side effects.
Otherwise returns the Some of the value.

Source
Quotes.scala
 def valueOrError[T](using FromExpr[T]): T
Return the value of this expression.
Return the value of this expression.
Emits an error and throws if the expression does not represent a value or possibly contains side effects.
Otherwise returns the value.

Source
Quotes.scala