| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Indigo.Internal.Field
Description
This module contains a datatype representing a lens to a field, helpers to compose new lens, and type class like StoreHasField returning a lens.
Synopsis
- type AccessFieldC a name = RElem name (ConstructorFieldNames a) (RIndex name (ConstructorFieldNames a))
- fetchField :: forall a name f proxy. AccessFieldC a name => proxy name -> Rec f (ConstructorFieldNames a) -> f name
- assignField :: forall a name f proxy. AccessFieldC a name => proxy name -> f name -> Rec f (ConstructorFieldNames a) -> Rec f (ConstructorFieldNames a)
- data FieldLens dt fname ftype where
- TargetField :: (InstrGetFieldC dt fname, InstrSetFieldC dt fname, GetFieldType dt fname ~ targetFType, AccessFieldC dt fname) => Label fname -> StoreFieldOps dt targetFName targetFType -> FieldLens dt targetFName targetFType
- DeeperField :: (AccessFieldC dt fname, InstrSetFieldC dt fname, HasField (GetFieldType dt fname) targetFName targetFType) => Label fname -> StoreFieldOps dt targetFName targetFType -> FieldLens dt targetFName targetFType
- flSFO :: FieldLens dt fname ftype -> StoreFieldOps dt fname ftype
- class (KnownValue ftype, KnownValue dt) => HasField dt fname ftype | dt fname -> ftype where
- fieldLensDeeper :: forall dt targetName targetType fname. (AccessFieldC dt fname, HasFieldOfType dt fname (GetFieldType dt fname), HasField (GetFieldType dt fname) targetName targetType) => Label fname -> FieldLens dt targetName targetType
- fieldLensADT :: forall dt targetFName targetFType fname. (InstrGetFieldC dt fname, InstrSetFieldC dt fname, GetFieldType dt fname ~ targetFType, AccessFieldC dt fname) => Label fname -> FieldLens dt targetFName targetFType
Documentation
type AccessFieldC a name = RElem name (ConstructorFieldNames a) (RIndex name (ConstructorFieldNames a)) Source #
Constraint to access/assign field stored in Rec
fetchField :: forall a name f proxy. AccessFieldC a name => proxy name -> Rec f (ConstructorFieldNames a) -> f name Source #
Get a field from list of fields
assignField :: forall a name f proxy. AccessFieldC a name => proxy name -> f name -> Rec f (ConstructorFieldNames a) -> Rec f (ConstructorFieldNames a) Source #
Assign a field to a value
Lens
data FieldLens dt fname ftype where Source #
Lens to a field.
obj.f1.f2.f3 is represented as list names of [f1, f2, f3].
dt is a type of source object (type of obj in example above)
fname is a name of target field ("f3" in example above)
ftype is a type of target field
However, a lens contains not only name of field but for each field it contains operations to get and set target field.
Constructors
| TargetField :: (InstrGetFieldC dt fname, InstrSetFieldC dt fname, GetFieldType dt fname ~ targetFType, AccessFieldC dt fname) => Label fname -> StoreFieldOps dt targetFName targetFType -> FieldLens dt targetFName targetFType | |
| DeeperField :: (AccessFieldC dt fname, InstrSetFieldC dt fname, HasField (GetFieldType dt fname) targetFName targetFType) => Label fname -> StoreFieldOps dt targetFName targetFType -> FieldLens dt targetFName targetFType |
flSFO :: FieldLens dt fname ftype -> StoreFieldOps dt fname ftype Source #
Access to StoreFieldOps
HasLens
class (KnownValue ftype, KnownValue dt) => HasField dt fname ftype | dt fname -> ftype where Source #
Class like StoreHasField type class but holding a lens to a field.
Instances
| (InstrSetFieldC dt fname, InstrGetFieldC dt fname, GetFieldType dt fname ~ ftype, AccessFieldC dt fname, KnownSymbol fname, KnownValue ftype, KnownValue dt) => HasField dt fname ftype Source # | Default instance for datatype and its direct field name. It will be useful unless you want to refer to a field using a custom name. |
Defined in Indigo.Internal.Field | |
fieldLensDeeper :: forall dt targetName targetType fname. (AccessFieldC dt fname, HasFieldOfType dt fname (GetFieldType dt fname), HasField (GetFieldType dt fname) targetName targetType) => Label fname -> FieldLens dt targetName targetType Source #
Build a lens to deeper field of an object.
fieldLensADT :: forall dt targetFName targetFType fname. (InstrGetFieldC dt fname, InstrSetFieldC dt fname, GetFieldType dt fname ~ targetFType, AccessFieldC dt fname) => Label fname -> FieldLens dt targetFName targetFType Source #
Build a lens to a direct field of an object.