Safe Haskell	None
Language	Haskell2010

DataFrame.Internal.Schema

Description

Runtime schema representation. The Template-Haskell deriveSchema splice lives in DataFrame.Internal.Schema.TH so this module can be used from packages that do not depend on template-haskell.

Synopsis

data SchemaType where
- SType :: forall a. (Columnable a, Read a) => Proxy a -> SchemaType
schemaType :: (Columnable a, Read a) => SchemaType
newtype Schema = Schema {
- elements :: Map Text SchemaType
}
makeSchema :: [(Text, SchemaType)] -> Schema

Documentation

data SchemaType where Source #

A runtime tag for a column’s element type.

Constructors

SType :: forall a. (Columnable a, Read a) => Proxy a -> SchemaType

Constructor carrying a Proxy of the element type.

Instances

Instances details

Show SchemaType Source #	Show the underlying element type using `typeRep`. Examples Expand `>>>` `:set -XTypeApplications``>>>` `show (schemaType @Bool)`"Bool"
Instance details Defined in DataFrame.Internal.Schema Methods showsPrec :: Int -> SchemaType -> ShowS # show :: SchemaType -> String # showList :: [SchemaType] -> ShowS #
Eq SchemaType Source #	Two `SchemaType`s are equal iff their element types are the same. Examples Expand `>>>` `:set -XTypeApplications``>>>` `schemaType @Int == schemaType @Int`True `>>>` `schemaType @Int == schemaType @Integer`False
Instance details Defined in DataFrame.Internal.Schema Methods (==) :: SchemaType -> SchemaType -> Bool # (/=) :: SchemaType -> SchemaType -> Bool #

schemaType :: (Columnable a, Read a) => SchemaType Source #

Construct a SchemaType for the given a.

Examples

Expand

>>> :set -XTypeApplications
>>> schemaType @T.Text == schemaType @T.Text
True

>>> show (schemaType @Double)
"Double"

newtype Schema Source #

Logical schema of a DataFrame: a mapping from column names to their element types (SchemaType).

Constructors

Schema
Fields elements :: Map Text SchemaType Mapping from column name to its `SchemaType`. Invariant: keys are unique column names. A missing key means the column is not present in the schema.

Instances

Instances details

Show Schema Source #
Instance details Defined in DataFrame.Internal.Schema Methods showsPrec :: Int -> Schema -> ShowS # show :: Schema -> String # showList :: [Schema] -> ShowS #
Eq Schema Source #
Instance details Defined in DataFrame.Internal.Schema Methods (==) :: Schema -> Schema -> Bool # (/=) :: Schema -> Schema -> Bool #

makeSchema :: [(Text, SchemaType)] -> Schema Source #

Construct a Schema from a list of (columnName, schemaType) pairs.