typocomath/src/core/Dispatcher.ts

110 lines
3.9 KiB
TypeScript

/* A Dispatcher is a collection of operations that do run-time
* dispatch on the types of their arguments. Thus, every individual
* method is like a typed-function (from the library by that name),
* but they can depend on one another and on ona another's implementations
* for specific types (including their own).
*/
type TypeName = string
type Parameter = TypeName
type Signature = Parameter[]
export class Specifications {}
export type typeOfDependency = {typeOf: (x: unknown) => TypeName}
//dummy implementation for now
export function joinTypes(a: TypeName, b: TypeName) {
if (a === b) return a
return 'any'
}
// Will need to build this up. Need to start with looping through the keys of
// values of keys, and filtering ones that start with Name, then add in
// checking the types.
// Some relevant stuff that worked in the playground:
// type KeysMatching<T, N, V> = {[K in keyof T]-?: T[K] extends V ? K extends `${string}${N}${string}` ? K : never : never}[keyof T];
// type ValuesMatching<T, V> = {[K in keyof T]: T[K] extends V ? T[K] : never}[keyof T]
// type SubKeysMatching<T, N, V> = {[K in keyof T]: KeysMatching<T[K], N, V>}[keyof T]
// type SubValuesMatching<T, V> = {[K in keyof T]: ValuesMatching<T[K], V>}[keyof T]
// let trial: SubKeysMatching<typeof Bar, 'ng', number | boolean> = 'strange'
// let valtrial: SubValuesMatching<typeof Bar, number> = 3
// type MyFunc = (...args: [string, number]) => any
// Selecting the proper key for arguments [string, number] is working
// let key: KeysMatching<typeof Foo, 'a', MyFunc > = 'bar' // OK, and 'baz' here does fail, as desired
// The above should have all of the ingredients.
type DependenciesType = Record<String, Function>
type FinalShape<FuncType> =
FuncType extends (arg: DependenciesType) => Function
? ReturnType<FuncType> : FuncType
type BeginsWith<Name> = `${Name}${string}`
type ImmediateDependency<Ob, Name, ParamTuple> =
{[K in keyof Ob]: K extends BeginsWith<Name>
? FinalShape<Ob[K]> extends (...args: ParamTuple) => any
? FinalShape<Ob[K]>
: never
: never}[keyof Ob]
type SpecType = typeof Specifications
export type ImplementationDependency<Name, ParamTuple> =
{[S in keyof SpecType]:
ImmediateDependency<SpecType[S], Name, ParamTuple>}[keyof SpecType]
type TypeSpecification = {
before?: TypeName[],
test: ((x: unknown) => boolean)
| ((d: DependenciesType) => (x: unknown) => boolean),
from: Record<Typename, Function>,
infer?: (d: DependenciesType) => (z: unknown) => TypeName
}
type SpecObject = Record<string, Function | TypeSpecification>
export type SpecifcationsGroup = Record<string, SpecObject>
export class Dispatcher {
installSpecification(
name: string,
signature: Signature,
returns: Type,
dependencies: Record<string, Signature>,
behavior: Function // possible todo: constrain this type based
// on the signature, return type, and dependencies. Not sure if
// that's really possible, though.
) {
console.log('Pretending to install', name, signature, '=>', returns)
//TODO: implement me
}
installType(name: TypeName, typespec: TypeSpecification) {
console.log('Pretending to install type', name, typespec)
//TODO: implement me
}
constructor(collection: SpecificationsGroup) {
for (key in collection) {
console.log('Working on', key)
for (identifier in collection[key]) {
console.log('Handling', key, ':', identifier)
const parts = identifier.split('_')
if (parts[parts.length - 1] === 'type') {
parts.pop()
const name = parts.join('_')
installType(name, collection[key][identifier])
} else {
const name = parts[0]
installSpecification(
name, ['dunno'], 'unsure', {}, collection[key][identifier])
}
}
}
}
}