[ new ] Add FromChar and FromDouble interfaces to the prelude (#1641)

libs/prelude/Builtin.idr

@@ -230,3 +230,47 @@ FromString String where
 public export
 defaultString : FromString String
 defaultString = %search
+
+%charLit fromChar
+
+||| Interface for types that can be constructed from char literals.
+public export
+interface FromChar ty where
+  constructor MkFromChar
+  ||| Conversion from Char.
+  fromChar : Char -> ty
+
+%allow_overloads fromChar
+
+%inline
+public export
+FromChar Char where
+  fromChar s = s
+
+%defaulthint
+%inline
+public export
+defaultChar : FromChar Char
+defaultChar = %search
+
+%doubleLit fromDouble
+
+||| Interface for types that can be constructed from double literals.
+public export
+interface FromDouble ty where
+  constructor MkFromDouble
+  ||| Conversion from Double.
+  fromDouble : Double -> ty
+
+%allow_overloads fromDouble
+
+%inline
+public export
+FromDouble Double where
+  fromDouble s = s
+
+%defaulthint
+%inline
+public export
+defaultDouble : FromDouble Double
+defaultDouble = %search

tests/idris2/basic056/DoubleLit.idr

@@ -1,14 +1,5 @@
 import Data.So
 
-%doubleLit fromDouble
-
-public export
-interface FromDouble ty where
-  fromDouble : Double -> ty
-
-%allow_overloads fromDouble
-
-
 record Newtype where
   constructor
   MkNewtype

tests/idris2/error018/expected

@@ -30,7 +30,7 @@ Issue1031-3:4:6--4:7
 
 1/1: Building Issue1031-4 (Issue1031-4.idr)
 Error: While processing left hand side of nice. Unsolved holes:
-Main.{dotTm:335} introduced at: 
+Main.{dotTm:373} introduced at: 
 Issue1031-4:4:6--4:10
  1 | %default total
  2 | 

tests/idris2/interactive019/expected

@@ -13,7 +13,9 @@ Prelude.Cast.cast : Char -> String
 Main> Prelude.const : a -> b -> a
   Constant function. Ignores its second argument.
   Totality: total
-Main> Prelude.toUpper : Char -> Char
+Main> Builtin.fromChar : Char -> Char
+
+Prelude.toUpper : Char -> Char
   Convert a letter to the corresponding upper-case letter, if any.
   Non-letters are ignored.
   Totality: total

tests/idris2/reflection003/expected

@@ -35,7 +35,7 @@ refprims:49:10--49:25
  49 | dummy3 = %runElab logBad
                ^^^^^^^^^^^^^^^
 
-Error: While processing right hand side of dummy4. Error during reflection: failed after generating Main.{plus:XXX}
+Error: While processing right hand side of dummy4. Error during reflection: failed after generating Main.{plus:XXXX}
 
 refprims:52:10--52:28
  48 | dummy3 : a