Documentation

An Environment captured for later consumption by type directed search

Results of applying type directed search to the previously captured Environment

A type class

A type operator

A type constructor with data constructors

A value

A value-level operator

A type class instance, created during typeclass desugaring

A module, in its entirety

A value re-exported from another module. These will be inserted during elaboration in name desugaring.

An import with no explicit list: `import M`.

An import with an explicit list of references to import: `import M (foo)`

An import with a list of references to hide: `import M hiding (foo)`

A data type declaration (data or newtype, name, arguments, data constructors)

A minimal mutually recursive set of data type declarations

A type synonym declaration (name, arguments, type)

A kind signature declaration

A role declaration (name, roles)

A type declaration for a value (name, ty)

A value declaration (name, top-level binders, optional guard, value)

A declaration paired with pattern matching in let-in expression (binder, optional guard, value)

A minimal mutually recursive set of value declarations

A foreign import declaration (name, type)

A data type foreign import (name, kind)

A fixity declaration

A module import (module name, qualifiedunqualifiedhiding, optional "qualified as" name)

A type class declaration (name, argument, implies, member declarations)

A type instance declaration (instance chain, chain index, name, dependencies, class name, instance types, member declarations)

The first SourceAnn serves as the annotation for the entire declaration, while the second SourceAnn serves as the annotation for the type class and its arguments.

This is a derived instance

This is an instance derived from a newtype

This is a regular (explicit) instance

A literal value

A prefix -, will be desugared

Binary operator application. During the rebracketing phase of desugaring, this data constructor will be removed.

Explicit parentheses. During the rebracketing phase of desugaring, this data constructor will be removed.

Note: although it seems this constructor is not used, it _is_ useful, since it prevents certain traversals from matching.

An record property accessor expression (e.g. `obj.x` or `_.x`). Anonymous arguments will be removed during desugaring and expanded into a lambda that reads a property from a record.

Partial record update

Object updates with nested support: `x { foo { bar = e } }` Replaced during desugaring into a Let and nested ObjectUpdates

Function introduction

Function application

A type application (e.g. `f @Int`)

Hint that an expression is unused. This is used to ignore type class dictionaries that are necessarily empty. The inner expression lets us solve subgoals before eliminating the whole expression. The code gen will render this as undefined, regardless of what the inner expression is.

Variable

An operator. This will be desugared into a function during the "operators" phase of desugaring.

Conditional (if-then-else expression)

A data constructor

A case expression. During the case expansion phase of desugaring, top-level binders will get desugared into case expressions, hence the need for guards and multiple binders per branch here.

A value with a type annotation

A let binding

A do-notation block

An ado-notation block

A placeholder for a type class dictionary to be inserted later. At the end of type checking, these placeholders will be replaced with actual expressions representing type classes dictionaries which can be evaluated at runtime. The constructor arguments represent (in order): whether or not to look at superclass implementations when searching for a dictionary, the type class name and instance type, and the type class dictionaries in scope.

A placeholder for a superclass dictionary to be turned into a TypeClassDictionary during typechecking

A placeholder for a type class instance to be derived during typechecking

A placeholder for an anonymous function argument

A typed hole that will be turned into a hint/error during typechecking

A value with source position information