Exprs
Expr wraps an abstract syntax tree and tags it with its type.
Expr wraps an abstract syntax tree and tags it with its type. The main source of information about exprs is the scala.reflect.api.Exprs page.
Constructor/Extractor for Expr.
Constructor/Extractor for Expr.
Can be useful, when having a tree and wanting to splice it in reify call, in which case the tree first needs to be wrapped in an expr.
The main source of information about exprs is the scala.reflect.api.Exprs page.
EXPERIMENTAL
A trait that defines strongly-typed tree wrappers and operations on them for use in Scala Reflection.
Exprwraps an abstract syntax tree (scala.reflect.api.Trees#Tree) and tags it with its type (scala.reflect.api.Types#Type).Usually
Exprs are created via scala.reflect.api.Universe#reify, in which case a compiler produces a scala.reflect.api.TreeCreator for the provided expression and also creates a complementary scala.reflect.api.TypeTags#WeakTypeTag that corresponds to the type of that expression.Exprs can also be created manually via theExprcompanion object, but then the burden of providing aTreeCreatorlies on the programmer. Compile-time reflection via macros, as described in scala.reflect.macros.Aliases, provides an easier way to instantiate exprs manually. Manual creation, however, is very rarely needed when working with runtime reflection.Exprcan be migrated from one mirror to another by using theinmethod. Migration means that all symbolic references to classes/objects/packages in the expression are re-resolved within the new mirror (typically using that mirror's classloader). The default universe of anExpris typically scala.reflect.runtime#universe, the default mirror is typically scala.reflect.runtime#currentMirror.