-- | This module provides documentation for the builtin Prim module. module Language.PureScript.Docs.Prim (primDocsModule) where import Prelude.Compat hiding (fail) import Data.Text (Text) import qualified Data.Text as T import qualified Data.Map as Map import qualified Data.Set as Set import Language.PureScript.Docs.Types import qualified Language.PureScript as P primDocsModule :: Module primDocsModule = Module { modName = P.moduleNameFromString "Prim" , modComments = Just "The Prim module is embedded in the PureScript compiler in order to provide compiler support for certain types — for example, value literals, or syntax sugar." , modDeclarations = [ function , array , record , number , int , string , char , boolean , partial , fail , warn , union , rowCons , typeConcat , typeString , kindType , kindSymbol ] , modReExports = [] } unsafeLookup :: forall v (a :: P.ProperNameType). Map.Map (P.Qualified (P.ProperName a)) v -> String -> Text -> v unsafeLookup m errorMsg name = go name where go = fromJust' . flip Map.lookup m . P.primName fromJust' (Just x) = x fromJust' _ = P.internalError $ errorMsg ++ show name primKind :: Text -> Text -> Declaration primKind title comments = if Set.member (P.primName title) P.primKinds then Declaration { declTitle = title , declComments = Just comments , declSourceSpan = Nothing , declChildren = [] , declInfo = ExternKindDeclaration } else P.internalError $ "Docs.Prim: No such Prim kind: " ++ T.unpack title lookupPrimTypeKind :: Text -> P.Kind lookupPrimTypeKind = fst . unsafeLookup P.primTypes "Docs.Prim: No such Prim type: " primType :: Text -> Text -> Declaration primType title comments = Declaration { declTitle = title , declComments = Just comments , declSourceSpan = Nothing , declChildren = [] , declInfo = ExternDataDeclaration (lookupPrimTypeKind title) } -- | Lookup the TypeClassData of a Prim class. This function is specifically -- not exported because it is partial. lookupPrimClass :: Text -> P.TypeClassData lookupPrimClass = unsafeLookup P.primClasses "Docs.Prim: No such Prim class: " primClass :: Text -> Text -> Declaration primClass title comments = Declaration { declTitle = title , declComments = Just comments , declSourceSpan = Nothing , declChildren = [] , declInfo = let tcd = lookupPrimClass title args = P.typeClassArguments tcd superclasses = P.typeClassSuperclasses tcd fundeps = convertFundepsToStrings args (P.typeClassDependencies tcd) in TypeClassDeclaration args superclasses fundeps } kindType :: Declaration kindType = primKind "Type" $ T.unlines [ "`Type` (also known as `*`) is the kind of all proper types: those that" , "classify value-level terms." , "For example the type `Boolean` has kind `Type`; denoted by `Boolean :: Type`." ] kindSymbol :: Declaration kindSymbol = primKind "Symbol" $ T.unlines [ "`Symbol` is the kind of type-level strings." , "" , "Construct types of this kind using the same literal syntax as documented" , "for strings." ] function :: Declaration function = primType "Function" $ T.unlines [ "A function, which takes values of the type specified by the first type" , "parameter, and returns values of the type specified by the second." , "In the JavaScript backend, this is a standard JavaScript Function." , "" , "The type constructor `(->)` is syntactic sugar for this type constructor." , "It is recommended to use `(->)` rather than `Function`, where possible." , "" , "That is, prefer this:" , "" , " f :: Number -> Number" , "" , "to either of these:" , "" , " f :: Function Number Number" , " f :: (->) Number Number" ] array :: Declaration array = primType "Array" $ T.unlines [ "An Array: a data structure supporting efficient random access. In" , "the JavaScript backend, values of this type are represented as JavaScript" , "Arrays at runtime." , "" , "Construct values using literals:" , "" , " x = [1,2,3,4,5] :: Array Int" ] record :: Declaration record = primType "Record" $ T.unlines [ "The type of records whose fields are known at compile time. In the" , "JavaScript backend, values of this type are represented as JavaScript" , "Objects at runtime." , "" , "The type signature here means that the `Record` type constructor takes" , "a row of concrete types. For example:" , "" , " type Person = Record (name :: String, age :: Number)" , "" , "The syntactic sugar with curly braces `{ }` is generally preferred, though:" , "" , " type Person = { name :: String, age :: Number }" ] number :: Declaration number = primType "Number" $ T.unlines [ "A double precision floating point number (IEEE 754)." , "" , "Construct values of this type with literals:" , "" , " y = 35.23 :: Number" , " z = 1.224e6 :: Number" ] int :: Declaration int = primType "Int" $ T.unlines [ "A 32-bit signed integer. See the purescript-integers package for details" , "of how this is accomplished when compiling to JavaScript." , "" , "Construct values of this type with literals:" , "" , " x = 23 :: Int" ] string :: Declaration string = primType "String" $ T.unlines [ "A String. As in JavaScript, String values represent sequences of UTF-16" , "code units, which are not required to form a valid encoding of Unicode" , "text (for example, lone surrogates are permitted)." , "" , "Construct values of this type with literals, using double quotes `\"`:" , "" , " x = \"hello, world\" :: String" , "" , "Multi-line string literals are also supported with triple quotes (`\"\"\"`)." ] char :: Declaration char = primType "Char" $ T.unlines [ "A single character (UTF-16 code unit). The JavaScript representation is a" , "normal String, which is guaranteed to contain one code unit. This means" , "that astral plane characters (i.e. those with code point values greater" , "than 0xFFFF) cannot be represented as Char values." , "" , "Construct values of this type with literals, using single quotes `'`:" , "" , " x = 'a' :: Char" ] boolean :: Declaration boolean = primType "Boolean" $ T.unlines [ "A JavaScript Boolean value." , "" , "Construct values of this type with the literals `true` and `false`." ] partial :: Declaration partial = primClass "Partial" $ T.unlines [ "The Partial type class is used to indicate that a function is *partial,*" , "that is, it is not defined for all inputs. In practice, attempting to use" , "a partial function with a bad input will usually cause an error to be" , "thrown, although it is not safe to assume that this will happen in all" , "cases. For more information, see" , "[the Partial type class guide](https://github.com/purescript/documentation/blob/master/guides/The-Partial-type-class.md)." ] fail :: Declaration fail = primClass "Fail" $ T.unlines [ "The Fail type class is part of the custom type errors feature. To provide" , "a custom type error when someone tries to use a particular instance," , "write that instance out with a Fail constraint." , "" , "For more information, see" , "[the Custom Type Errors guide](https://github.com/purescript/documentation/blob/master/guides/Custom-Type-Errors.md)." ] warn :: Declaration warn = primClass "Warn" $ T.unlines [ "The Warn type class allows a custom compiler warning to be displayed." , "" , "For more information, see" , "[the Custom Type Errors guide](https://github.com/purescript/documentation/blob/master/guides/Custom-Type-Errors.md)." ] union :: Declaration union = primClass "Union" $ T.unlines [ "The Union type class is used to compute the union of two rows of types" , "(left-biased, including duplicates)." , "" , "The third type argument represents the union of the first two." ] rowCons :: Declaration rowCons = primClass "RowCons" $ T.unlines [ "The RowCons type class is a 4-way relation which asserts that one row of" , "types can be obtained from another by inserting a new label/type pair on" , "the left." ] typeConcat :: Declaration typeConcat = primType "TypeConcat" $ T.unlines [ "The TypeConcat type constructor concatenates two Symbols in a custom type" , "error." , "" , "For more information, see" , "[the Custom Type Errors guide](https://github.com/purescript/documentation/blob/master/guides/Custom-Type-Errors.md)." ] typeString :: Declaration typeString = primType "TypeString" $ T.unlines [ "The TypeString type constructor renders any concrete type into a Symbol" , "in a custom type error." , "" , "For more information, see" , "[the Custom Type Errors guide](https://github.com/purescript/documentation/blob/master/guides/Custom-Type-Errors.md)." ]