ConstraintTP
This project has been inspired from Dependent Type Provider
It provides compile-time constraints over basic F# types.
The goal would be to allow coders to create types according to specific rules and having value constraint over these rules at compile-time.
Rule system
The rule system is the following: We consider that each type could be shrinked down to a subset according to a specific rule. The rule would be written as a string representation of a function and would return the function itself. The type of the rule even though it is a string should, when evaluated by the fsi Session, be :
'a -> bool
either the value given follows the rule (true) or not (false).
For instance, if one wants to define a type with all the integers multiple of 3, he would write :
let [<Literal>] multiplesOf3Rule = "let f inputValue = inputValue % 3 = 0 \nf"
and would be called as a static parameter of ConstraintTP :
type DivisibleBy3 = Constraint.Numbers.ConstraintInt32<Rule = multiplesOf3Rule>
What is supported so far
System of rule :
A system of rule that is quite generic and type safe through the pre-évaluation with the fsi session running behind the scene.
Basic F# types :
- sbyte
- byte
- uint16
- int16
- uint32
- int32
- uint64
- int64
- float32
- float
As a non-basic F# types :
-
Arrays
type: 'a []
I could do any non-basic F# types like lists... However I think that there are some aspect I should work on before going further.
TODO
- String with compile-time Regex verification as follow
Type Foo = DependentType.String.Regex<".+@.+">
If one has some ideas regarding how we could take this TP to any direction please tell me, I would really appreciate.
Build process
run the following command :
.\build.cmd
Samples
Some basic samples could be found in Examples.fsx. You could also look at the slides I have prepared.