add another try

.npmrc

@@ -1 +0,0 @@
-shell-emulator=true

README.md

@@ -2,13 +2,50 @@
 
 A final (?) prototype for a refactor of mathjs, culminating the picomath, pocomath, typomath series. Provides an extensible core with "fuzzy" types for its operations, that can at any time generate exact .d.ts file for its current state.
 
+To build and run the prototype, run:
 
-Convenience scripts:
+```
+pnpm install
+pnpm build-and-run
+```
 
-* `pnpm build` -- compile the package
-* `pnpm exec` -- run the compiled code produced by `pnpm build`
-* `pnpm go` -- both of the above in sequence.
+## experiment
 
-Important installation note:
+Have a look at the section under `/src/experiment` and `/src/plugins`:
 
-after `pnpm install`, you must execute `npx ts-patch install` to activate the ts-macros compiler plugin.
+- `src/plugins/typeInferPlugin.ts` is the actual plugin
+- in `tsconfig.json` we configure TypeScript to run the plugin
+- `src/experiment/arithmeticInfer.ts` with an example where we define `__infer__`
+- after running TypeScript: look at `build/experiment/arithmeticInfer.ts` where the `__infer__` string literal is replaced with the actual types
+
+### The idea
+
+Create a TypeScript plugin which can replace a string literal like `__infer__` in a typed-function definition:
+ 
+    typed('square', '__infer__', <T>(dep: { ... } => { ... })
+ 
+with the actual types, something like: 
+
+    typed('square', '{ deps: { multiply: (a: T, b: T) => T; }; return: (a: T) => T }', <T>(dep: { ... } => { ... })
+
+(We can discuss what syntax we like most, this is just a POC)
+
+### How to run
+ 
+    pnpm build-and-run
+ 
+### Read more
+ 
+- https://github.com/microsoft/TypeScript/wiki/Writing-a-Language-Service-Plugin
+- https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API
+- https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#using-the-type-checker
+- https://github.com/Microsoft/TypeScript/wiki/Using-the-Language-Service-API
+- https://stackoverflow.com/questions/63944135/typescript-compiler-api-how-to-get-type-with-resolved-type-arguments
+- https://stackoverflow.com/questions/48886508/typechecker-api-how-do-i-find-inferred-type-arguments-to-a-function
+- https://blog.logrocket.com/using-typescript-transforms-to-enrich-runtime-code-3fd2863221ed/
+- https://github.com/itsdouges/typescript-transformer-handbook#transforms
+
+### Interesting libraries
+
+- https://github.com/GoogleFeud/ts-macros/
+- https://ts-morph.com

etc/package.json

@@ -1 +0,0 @@
-{"type": "module"}

package.json5

@@ -1,16 +1,11 @@
 {
    name: 'typocomath',
-   version: '0.0.2',
+   version: '0.0.1',
    description: 'A hopeful final typescipt-pragmatic mathjs proof-of-concept',
    main: 'index.ts',
    scripts: {
-      test: 'echo "Error: no test specified" && exit 1',
-      build: 'mkdirp build && cpy etc/package.json build --flat && tsc',
-      start: 'node build',
-      go: 'pnpm clean && pnpm build && pnpm start',
-      clean: 'del-cli build',
+      'go': 'ttsc && echo {"type":"module"} > build/package.json && node build/index.js',
    },
-   packageManager: 'pnpm',
    keywords: [
       'math',
       'algebra',
@@ -22,14 +17,12 @@
       type: 'git',
       url: 'https://code.studioinfinity.org/glen/typocomath.git',
    },
+   dependencies: {
+      '@types/node': '20.5.7',
+   },
    devDependencies: {
-      '@types/node': '20.8.4',
-      'cpy-cli': '5.0.0',
-      'del-cli': '5.1.0',
-      mkdirp: '3.0.1',
-      'source-map': '0.7.4',
-      'ts-macros': '2.6.0',
-      'ts-patch': '3.0.2',
-      typescript: '5.1.6',
+      'ts-node': '10.9.1',
+      ttypescript: '1.5.15',
+      typescript: '4.7.4',
    },
 }

src/Complex/all.ts

@@ -1,6 +1,2 @@
-import * as Complex from './native.js'
-import * as complex from './arithmetic.js'
-
-export { complex }
-
-export {Complex}
+export * as Complex from './native.js'
+export * as complex from './arithmetic.js'

src/Complex/arithmetic.ts

@@ -2,7 +2,6 @@ import {Complex} from './type.js'
 import type {
    Dependencies, Signature, Returns, RealType, AliasOf
 } from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 declare module "../interfaces/type" {
    interface Signatures<T> {
@@ -79,10 +78,11 @@ export const sqrt =
        & Dependencies<'zero' | 'complex', T>
        & Dependencies<'absquare' | 're' | 'divideReal', Complex<T>>
        & {
-         addTR: Signature<'addReal', T>,
+         addTR: Signature<'addReal', T>, 
          addRR: Signature<'add', RealType<T>>,
          addCR: Signature<'addReal', Complex<T>>
-       }): Signature<'sqrt', Complex<T>> =>
+      }):
+      Signature<'sqrt', Complex<T>> =>
    z => {
       const myabs = dep.conservativeSqrt(dep.absquare(z))
       const r = dep.re(z)
@@ -98,7 +98,4 @@ export const sqrt =
       return dep.divideReal(num, denom)
    }
 
-$reflect!([
-   add, addReal, unaryMinus, conj, subtract, multiply, absquare, divideReal,
-   reciprocal, divide, sqrt
-])
+export const conservativeSqrt = sqrt

src/Complex/predicate.ts

@@ -1,13 +1,9 @@
 import {Complex} from './type.js'
 import type {Dependencies, Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export const isReal =
    <T>(dep: Dependencies<'add' | 'equal' | 'isReal', T>):
       Signature<'isReal', Complex<T>> =>
    z => dep.isReal(z.re) && dep.equal(z.re, dep.add(z.re, z.im))
 
-export const isSquare = (): Signature<'isSquare', Complex<unknown>> =>
-   z => true // FIXME: not correct for Complex<bigint> once we get there
-
-$reflect!([isReal, isSquare])
+export const isSquare: Signature<'isSquare', Complex<any>> = z => true // FIXME: not correct for Complex<bigint> once we get there

src/Complex/relational.ts

@@ -1,8 +1,6 @@
 import {Complex} from './type.js'
 import {Dependencies, Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export const equal =
    <T>(dep: Dependencies<'equal', T>): Signature<'equal', Complex<T>> =>
    (w, z) => dep.equal(w.re, z.re) && dep.equal(w.im, z.im)
-$reflect!([equal])

src/Complex/type.ts

@@ -2,12 +2,10 @@ import {joinTypes, typeOfDependency} from '../core/Dispatcher.js'
 import type {
    ZeroType, OneType, NaNType, Dependencies, Signature, Returns
 } from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export type Complex<T> = { re: T; im: T; }
 
 export const Complex_type = {
-   name: 'Complex', // just until we have reflection to tell us
    test: <T>(dep: { testT: (z: unknown) => z is T }) =>
       (z: unknown): z is Complex<T> =>
          typeof z === 'object' && z != null && 're' in z && 'im' in z
@@ -63,5 +61,3 @@ export const nan =
 export const re =
    <T>(dep: Dependencies<'re', T>): Signature<'re', Complex<T>> =>
    z => dep.re(z.re)
-
-$reflect!([complex, zero, one, nan, re])

src/core/$reflect.ts

@@ -0,0 +1,11 @@
+export function $reflect<T>(arg: T, types?: string) : T {
+  // TODO: implement typed-function for real
+  if (!types) {
+    console.error('types should be resolved with runtime type information by the TypeScript plugin')
+  }
+
+  console.log(`INFER: Creating function with types ${types}`)
+
+  // TODO: here we can now turn the inputs into a real typed-function with a signature
+  return arg
+}

src/core/Dispatcher.ts

@@ -5,8 +5,6 @@
  * for specific types (including their own).
  */
 
-import {parseReflectedType, ImplementationDef} from './parseReflectedType.js'
-
 // First helper types and functions for the Dispatcher
 
 type TypeName = string
@@ -27,7 +25,6 @@ export function joinTypes(a: TypeName, b: TypeName) {
 // Now types used in the Dispatcher class itself
 
 type TypeSpecification = {
-   name: string, // just until we get reflection, then we can remove this property
    before?: TypeName[],
    test: ((x: unknown) => boolean)
       | ((d: DependenciesType) => (x: unknown) => boolean),
@@ -41,18 +38,18 @@ type SpecificationsGroup = Record<string, SpecObject>
 export class Dispatcher {
    installSpecification(
       name: string,
-      defn: ImplementationDef,
+      signature: Signature,
+      returns: TypeName,
+      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, 'with signatures')
-      for (const signature of defn.fn.signatures) {
-         console.log('   ', signature.args, '=>', signature.returns)
-      }
-      if (defn.fn.aliasOf) {
-         console.log('   As an alias of', defn.fn.aliasOf)
-      }
+      console.log('Pretending to install', name, signature, '=>', returns)
+
+      // @ts-ignore
+      // console.log(name, 'signature', reflect(signature))
+      // console.log(name, 'dependencies', reflect(dependencies))
       //TODO: implement me
    }
    installType(name: TypeName, typespec: TypeSpecification) {
@@ -60,25 +57,23 @@ export class Dispatcher {
       //TODO: implement me
    }
    constructor(collection: SpecificationsGroup) {
-      const implementations = []
       for (const key in collection) {
          console.log('Working on', key)
          for (const identifier in collection[key]) {
-            const item = collection[key][identifier]
-            if (typeof item === 'function') {
-               implementations.push([key, identifier, item])
-            } else {
-               console.log('Handling type', key, ':', identifier)
+            console.log('Handling', key, ':', identifier)
+            const parts = identifier.split('_')
+            if (parts[parts.length - 1] === 'type') {
+               parts.pop()
+               const name = parts.join('_')
                this.installType(
-                  item.name, collection[key][identifier] as TypeSpecification)
+                  name, collection[key][identifier] as TypeSpecification)
+            } else {
+               const name = parts[0]
+               this.installSpecification(
+                  name, ['dunno'], 'unsure', {},
+                  collection[key][identifier] as Function)
             }
          }
       }
-      for (const trio of implementations) {
-         const [k, id, imp] = trio
-         console.log('Handling implementation', id, 'from', k)
-         this.installSpecification(
-            id, parseReflectedType(id, imp.reflectedType), imp)
-      }
    }
 }

src/core/parseReflectedType.ts

@@ -1,279 +0,0 @@
-export type FunctionDef = {
-  name: string,
-  aliasOf?: string,
-  signatures: Array<{
-    args: Array<{ name: string, type: string }>
-    returns: string
-  }>
-}
-
-
-export type ImplementationDef = {
-  fn: FunctionDef,
-  dependencies: Record<string, FunctionDef>
-  genericParameter: string | null
-}
-
-/**
- * Parse a reflected type coming out of TypeScript into a structured object, for example:
- *
- *   '<T>(dep: configDependency & { complex: ((re: number) => Complex<number>) | ((re: number, im: number) => Complex<number>); }) => (a: number) => number | Complex<number>'
- */
-export function parseReflectedType(name: string, reflectedType: string): ImplementationDef {
-  console.log('For', name, 'parsing', reflectedType)
-  const [factoryArgs, fnsClause] = split(reflectedType, '=>', 2).map(trim)
-  const fn = parseAlias(name, fnsClause)
-
-  // extract the generic parameter like '<T>' at the start of the type
-  const genericParameter = factoryArgs.trim().startsWith('<')
-    ? findBlockContents(factoryArgs, '<', '>')?.innerText || null
-    : null
-
-  const factoryArgsInner = findBlockContents(factoryArgs, '(', ')')
-  const depArg = split(factoryArgsInner.innerText, ':').map(trim)[1]
-  const depArgBlocks: string[] = depArg ? split(depArg, '&').map(trim) : []
-
-  const deps = depArgBlocks
-    .filter(depArgBlock => {
-      if (depArgBlock.startsWith('{') || depArgBlock === 'configDependency') {
-        return true
-      } else {
-        throw new SyntaxError(`Cannot parse dependency "${depArgBlock}"`)
-      }
-    })
-    .flatMap(parseDependencies)
-
-  const dependencies: Record<string, FunctionDef> = groupBy(deps, 'name')
-
-  return {fn, dependencies, genericParameter }
-}
-
-function parseDependencies(deps: string): FunctionDef[] {
-  if (deps === 'configDependency') {
-    return [{name: 'config', signatures: [{args: [], returns: 'Config'}]}]
-  }
-  const inner = findBlockContents(deps, '{', '}').innerText
-  return split(inner, ';')
-    .map(trim)
-    .filter(notEmpty)
-    .map(parseDependency)
-}
-
-// parse a dependency like "complex: ((re: number) => Complex<number>) | ((re: number, im: number) => Complex<number>)"
-function parseDependency(dep: string): FunctionDef {
-  const [name, def] = split(dep, ':').map(trim)
-
-  return parseAlias(name, def)
-}
-
-// Parse a possibly aliased function
-function parseAlias(name: string, alias: string): FunctionDef {
-  const { aliasOf, innerSignature } = parseAliasOf(alias)
-
-  return { name, signatures: parseSignatures(innerSignature), aliasOf }
-}
-
-// parse function signatures like ((re: number) => Complex<number>) | ((re: number, im: number) => Complex<number>)
-// But also have to succeed on (a: number) => number | Complex<number>
-// That's why we only split on an alternation bar `|` that's followed by
-// a parenthesis; that way we avoid splitting a union return type. Note
-// this is not necessarily foolproof, as there could be a return type that
-// is a union with a complicated piece that has to be enclosed in parens;
-// but so far it seems to work in practice.
-function parseSignatures(sigs: string) {
-  return split(sigs, /[|]\s*(?=[(])/)
-    .map(trim)
-    .map(stripParenthesis)
-    .map(signature => {
-      const [argsBlock, returns] = split(signature, '=>').map(trim)
-
-      if (!returns) {
-        throw new SyntaxError(`Failed to find return type in '${signature}'`)
-      }
-
-      return {
-        args: parseArgs(argsBlock),
-        returns
-      }
-    })
-}
-
-// parse args like "(re: number, im: number)"
-function parseArgs(argsBlock: string) : Array<{name: string, type: string}> {
-  const args = findBlockContents(argsBlock, '(', ')').innerText
-
-  return split(args, ',')
-    .map(trim)
-    .map(arg => {
-      const [name, type] = split(arg, ':').map(trim)
-      return { name, type}
-    })
-}
-
-// parse "AliasOf<"divide", (a: Complex<T>, b: RealType<Complex<T>>) => Complex<T>>"
-function parseAliasOf(signature: string) : { innerSignature: string, aliasOf: string | undefined } {
-  if (!signature.startsWith('AliasOf')) {
-    return {
-      innerSignature: signature,
-      aliasOf: undefined
-    }
-  }
-
-  const inner = findBlockContents(signature, '<', '>').innerText.trim()
-  const [aliasOfWithQuotes, innerSignature] = split(inner, ',').map(trim)
-  return {
-    innerSignature,
-    aliasOf: aliasOfWithQuotes.substring(1, aliasOfWithQuotes.length - 1) // remove double quotes
-  }
-}
-
-// remove the outer parenthesis, for example "((re: number) => Complex<number>)" returns "(re: number) => Complex<number>"
-function stripParenthesis(text: string) : string {
-  return text.startsWith('(') && text.endsWith(')')
-    ? text.substring(1, text.length - 1)
-    : text
-}
-
-function findBlockContents(text: string, blockStart: string, blockEnd: string, startIndex = 0) : { start: number, end: number, innerText: string } | undefined {
-  let i = startIndex
-
-  while (!matchSubString(text, blockStart, i) && i < text.length) {
-    i++
-  }
-
-  if (i >= text.length) {
-    return undefined
-  }
-
-  i++
-  const start = i
-
-  while (!matchSubString(text, blockEnd, i) || matchSubString(text, '=>', i - 1)) {
-    i = skipBrackets(text, i)
-
-    i++
-  }
-
-  if (i >= text.length) {
-    return undefined
-  }
-  const end = i
-
-  return {
-    start,
-    end,
-    innerText: text.substring(start, end)
-  }
-}
-
-/**
- * Given a string, generate a string source for a regexp that will match
- * exactly the given string.
- * Uses the fact that the only characters that need to be escaped in
- * a character class are \, ], and ^
- */
-function regexpQuote(s: string) {
-  const special = '\\]^'
-  let re = ''
-  for (const char of s) {
-    if (special.includes(char)) re += `\\${char}`
-    else re += `[${char}]`
-  }
-  return re
-}
-
-/**
- * Split a string by a delimiter, but ignore all occurrences of the delimiter
- * that are inside bracket pairs <> () [] {}
- */
-export function split(
-     text: string, delimiter: string | RegExp, pieces = 0): string[] {
-  const delim: RegExp = typeof delimiter === 'string'
-     ? new RegExp(regexpQuote(delimiter), 'y')
-     : new RegExp(delimiter.source, 'y')
-  const parts: string[] = []
-
-  let i = 0
-  let n = 1
-  let start = 0
-  while (i < text.length && (pieces === 0 || n < pieces)) {
-    i = skipBrackets(text, i)
-
-    delim.lastIndex = i
-    const result = delim.exec(text)
-    if (result) {
-      parts.push(text.substring(start, i))
-      n += 1
-      i += result[0].length
-      start = i
-    }
-
-    i++
-  }
-
-  parts.push(text.substring(start))
-
-  return parts
-}
-
-function skipBrackets(text: string, startIndex: number) : number {
-  let level = 0
-  let i = startIndex
-
-  do {
-    if (isBracketOpen(text, i)) {
-      level++
-    }
-
-    if (isBracketClose(text, i) && level > 0) {
-      level--
-    }
-
-    if (level === 0) {
-      break
-    }
-
-    i++
-  } while(i < text.length)
-
-  return i
-}
-
-function isBracketOpen(text: string, index: number) {
-  const char = text[index]
-  return char === '(' || char === '<' || char === '[' || char === '{'
-}
-
-function isBracketClose(text: string, index: number) {
-  const char = text[index]
-  // we need to take care of not matching the ">" of the operator "=>"
-  return char === ')' || (char === '>' && text[index - 1] !== '=') || char === ']' || char === '}'
-}
-
-function matchSubString(text: string, search: string, index: number) : boolean {
-  for (let i = 0; i < search.length; i++) {
-    if (text[i + index] !== search[i]) {
-      return false
-    }
-  }
-
-  return true
-}
-
-function trim(text: string) : string {
-  return text.trim()
-}
-
-function notEmpty(text: string) : boolean {
-  return text.length > 0
-}
-
-function groupBy<T>(items: T[], key: string) : Record<string, T> {
-  const obj: Record<string, T> = {}
-
-  items.forEach((item) => {
-    obj[item[key]] = item
-  })
-
-  return obj
-}

src/experiment/arithmeticInfer.ts

@@ -0,0 +1,19 @@
+import { $reflect } from '../core/$reflect.js'
+import { Dependencies } from '../interfaces/type.js'
+
+// unaryMinus dep is just for the experiment
+// FIXME: the typescript plugin should resolve Dependencies<'multiply' | 'unaryMinus', T>
+export const square = $reflect(<T>(dep: Dependencies<'multiply' | 'unaryMinus', T>): (a: T) => T =>
+  z => dep.multiply(z, z)
+)
+
+// export const square2 = function $reflect<T>(dep: Dependencies<'multiply' | 'unaryMinus', T>) {
+//   return (z: T) => dep.multiply(z, z)
+// }
+
+// export const square = $reflect(<T>(dep: {
+//     multiply: (a: T, b: T) => T,
+//     unaryMinus: (x: T) => T, // just for the experiment
+//   }): (a: T) => T =>
+//   z => dep.multiply(z, z)
+// )

src/generic/arithmetic.ts

@@ -1,9 +1,5 @@
 import type {Dependencies, Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export const square =
    <T>(dep: Dependencies<'multiply', T>): Signature<'square', T> =>
    z => dep.multiply(z, z)
-   // z => dep.fooBar(z, z) // fails as desired
-   // z => dep.multiply(z, 'foo') // still fails as desired
-$reflect!([square])

src/generic/relational.ts

@@ -1,7 +1,5 @@
 import {Dependencies, Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export const unequal =
    <T>(dep: Dependencies<'equal', T>): Signature<'unequal', T> =>
    (x, y) => !dep.equal(x, y)
-$reflect!([unequal])

src/index.ts

@@ -1,53 +1,28 @@
-import {inspect} from 'node:util'
-import {Dispatcher} from './core/Dispatcher.js'
-import * as Specifications from './all.js'
+import { Complex } from './Complex/type.js'
+import { absquare as absquare_complex } from './Complex/arithmetic.js'
+import { square } from './experiment/arithmeticInfer.js'
 
-export default new Dispatcher(Specifications)
-
-import {Complex} from './Complex/type.js'
-import {absquare as absquare_complex} from './Complex/arithmetic.js'
-import {parseReflectedType} from './core/parseReflectedType.js'
-
-const mockRealAdd = (a: number, b: number) => a+b
-const mockComplexAbsquare = (z: Complex<number>) => z.re*z.re + z.im*z.im
-const mockComplex = (re: number, im: number) => ({ re, im })
-
-const config = {
-  predictable: false,
-  epsilon: 1e-14
-}
+const add = (a: number, b: number) => a + b
+const multiply = (a: number, b: number) => a * b
+const unaryMinus = (a: number) => -a
+const absquare = (z: Complex<number>) => z.re * z.re + z.im * z.im
 
 const quatAbsquare = absquare_complex({
-  add: mockRealAdd,
-  absquare: mockComplexAbsquare
+    add,
+    absquare
 })
 
-const myabs = quatAbsquare({re: {re: 0, im: 1}, im: {re:2, im: 3}})
-const typeTest: typeof myabs = 7 // check myabs is just a number
-console.log('Result is myabs=', myabs)
+const result = quatAbsquare({re: {re: 0, im: 1}, im: {re:2, im: 3}})
+const typeTest: typeof result = 7 // check myabs is just a number
 
-const sqrt = Specifications.numbers.sqrt({
-  config,
-  complex: mockComplex
+console.log()
+console.log('Result is', result)
+
+
+const mySquare = square({
+  multiply,
+  unaryMinus
 })
-console.log('Result of sqrt(16)=', sqrt(16))
-console.log('Result of sqrt(-4)=', sqrt(-4))
 
 console.log()
-console.log('1) NUMBER SQRT')
-console.log(`1.1) REFLECTED TYPE: "${Specifications.numbers.sqrt.reflectedType}"`)
-console.log(
-  '1.2) PARSED TYPE:',
-  inspect(
-    parseReflectedType('sqrt', Specifications.numbers.sqrt.reflectedType),
-    { depth: null, colors: true }))
-
-console.log()
-console.log('2) GENERIC SQUARE')
-console.log(`1.1) REFLECTED TYPE: "${Specifications.generic.square.reflectedType}"`)
-console.log('2.2) PARSED TYPE:', inspect(parseReflectedType('square', Specifications.generic.square.reflectedType), { depth: null, colors: true }))
-
-console.log()
-console.log('3) COMPLEX SQRT')
-console.log(`1.1) REFLECTED TYPE: "${Specifications.complex.sqrt.reflectedType}"`)
-console.log('3.2) PARSED TYPE:', inspect(parseReflectedType('sqrt', Specifications.complex.sqrt.reflectedType), { depth: null, colors: true }))
+console.log('mySquare(4)=', mySquare(4))

src/interfaces/type.ts

@@ -1,5 +1,3 @@
-import {$$typeToString} from 'ts-macros'
-
 /*****
  * Every typocomath type has some associated types; they need
  * to be published in the following interface. The key is the
@@ -15,10 +13,6 @@ import {$$typeToString} from 'ts-macros'
  * but that's OK, the generic parameter doesn't hurt in those cases.
  ****/
 
-type ValueIntersectionByKeyUnion<T,  TKey extends keyof T> = {
-  [P in TKey]: (k: T[P])=>void
-} [TKey] extends ((k: infer I)=>void) ? I : never
-
 export interface AssociatedTypes<T> {
    undefined: {
       type: undefined
@@ -30,10 +24,10 @@ export interface AssociatedTypes<T> {
 }
 
 type AssociatedTypeNames = keyof AssociatedTypes<unknown>['undefined']
-type ALookup<T, Name extends AssociatedTypeNames> = ValueIntersectionByKeyUnion<{
+type ALookup<T, Name extends AssociatedTypeNames> = {
    [K in keyof AssociatedTypes<T>]:
-   T extends AssociatedTypes<T>[K]['type'] ? AssociatedTypes<T>[K][Name] : unknown},
-   keyof AssociatedTypes<T>>
+   T extends AssociatedTypes<T>[K]['type'] ? AssociatedTypes<T>[K][Name] : never
+}[keyof AssociatedTypes<T>]
 
 // For everything to compile, zero and one must be subtypes of T:
 export type ZeroType<T> = ALookup<T, 'zero'> & T
@@ -75,16 +69,7 @@ export interface Signatures<T> {
 type SignatureKey<T> = keyof Signatures<T>
 
 export type Signature<Name extends SignatureKey<T>, T> = Signatures<T>[Name]
-export type Returns<Name extends SignatureKey<T>, T> =
-   ReturnType<Signatures<T>[Name]>
-type Deps<T> =  T extends unknown ? { [K in keyof T]: T[K] } : never;
-export type Dependencies<Name extends SignatureKey<T>, T> =
-   Deps<{[K in Name]: Signature<K, T>}>
+export type Returns<Name extends SignatureKey<T>, T> = ReturnType<Signatures<T>[Name]>
+export type Dependencies<Name extends SignatureKey<T>, T> = {[K in Name]: Signature<K, T>}
 
 export type AliasOf<Name extends string, T> = T & {aliasOf?: Name}
-
-// For defining implementations with type reflection
-export function $reflect<ImplTuple>(tup: ImplTuple) {
-   +[[tup], <T>(elt: T) =>
-     elt.reflectedType = $$typeToString!<T>(true, false, true)]
-}

src/numbers/all.ts

@@ -1,3 +1 @@
-import * as numbers from './native.js'
-
-export {numbers}
+export * as numbers from './native.js'

src/numbers/arithmetic.ts

@@ -1,35 +1,25 @@
 import type {configDependency} from '../core/Config.js'
 import type {Dependencies, Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
-export const add =        (): Signature<'add',        number> => (a, b) => a + b
-const unaMinus = (a: number) => -a
-export const unaryMinus = (): Signature<'unaryMinus', number> => unaMinus
-export const conj =       (): Signature<'conj',       number> => a => a
-export const subtract =   (): Signature<'subtract',   number> => (a, b) => a - b
-export const multiply =   (): Signature<'multiply',   number> => (a, b) => a * b
-export const absquare =   (): Signature<'absquare',   number> => a => a * a
-export const reciprocal = (): Signature<'reciprocal', number> => a => 1 / a
-export const divide =     (): Signature<'divide',     number> => (a, b) => a / b
+export const add:        Signature<'add',        number> = (a, b) => a + b
+export const unaryMinus: Signature<'unaryMinus', number> = a => -a
+export const conj:       Signature<'conj',       number> = a => a
+export const subtract:   Signature<'subtract',   number> = (a, b) => a - b
+export const multiply:   Signature<'multiply',   number> = (a, b) => a * b
+export const absquare:   Signature<'absquare',   number> = a => a * a
+export const reciprocal: Signature<'reciprocal', number> = a => 1 / a
+export const divide:     Signature<'divide',     number> = (a, b) => a / b
 
 const basicSqrt = (a: number) => isNaN(a) ? NaN : Math.sqrt(a)
-export const conservativeSqrt = (): Signature<'conservativeSqrt', number> =>
-  basicSqrt
+export const conservativeSqrt: Signature<'conservativeSqrt', number> = basicSqrt
 
 export const sqrt =
-  (dep: configDependency
-   & Dependencies<'complex', number>): Signature<'sqrt', number> => {
-    if (dep.config.predictable || !dep.complex) {
-      return basicSqrt
-    }
-    return a => {
-      if (isNaN(a)) return NaN
-      if (a >= 0) return Math.sqrt(a)
-      return dep.complex(0, Math.sqrt(unaMinus(a)))
-    }
+   (dep: configDependency & Dependencies<'complex', number>):
+   Signature<'sqrt', number> => {
+      if (dep.config.predictable || !dep.complex) return basicSqrt
+      return a => {
+         if (isNaN(a)) return NaN
+         if (a >= 0) return Math.sqrt(a)
+         return dep.complex(0, Math.sqrt(unaryMinus(a)))
+      }
    }
-
-$reflect!([
-  add, unaryMinus, conj, subtract, multiply, absquare, reciprocal, divide,
-  conservativeSqrt, sqrt
-])

src/numbers/native.ts

@@ -1,4 +1,2 @@
 export * from './type.js'
 export * from './arithmetic.js'
-export * from './predicate.js'
-export * from './relational.js'

src/numbers/predicate.ts

@@ -1,7 +1,4 @@
 import type {Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
-export const isReal =   (): Signature<'isReal',   number> => (a) => true
-export const isSquare = (): Signature<'isSquare', number> => (a) => a >= 0
-
-$reflect!([isReal, isSquare])
+export const isReal:   Signature<'isReal',   number> = (a) => true
+export const isSquare: Signature<'isSquare', number> = (a) => a >= 0

src/numbers/relational.ts

@@ -1,6 +1,5 @@
 import {configDependency} from '../core/Config.js'
 import {Signature} from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 const DBL_EPSILON = Number.EPSILON || 2.2204460492503130808472633361816E-16
 
@@ -20,4 +19,3 @@ export const equal =
 
       return false
    }
-$reflect!([equal])

src/numbers/type.ts

@@ -1,8 +1,6 @@
 import type { Signature } from '../interfaces/type.js'
-import {$reflect} from '../interfaces/type.js'
 
 export const number_type = {
-   name: 'number', // just until we have reflection to tell us
    before: ['Complex'],
    test: (n: unknown): n is number => typeof n === 'number',
    from: { string: (s: string) => +s }
@@ -10,7 +8,7 @@ export const number_type = {
 
 declare module "../interfaces/type" {
    interface AssociatedTypes<T> {
-      number: {
+      numbers: {
          type: number
          zero: 0
          one: 1
@@ -21,9 +19,7 @@ declare module "../interfaces/type" {
 }
 
 // I don't like the redundancy of repeating 'zero'; any way to eliminate that?
-export const zero = (): Signature<'zero', number> => (a) => 0
-export const one =  (): Signature<'one',  number> => (a) => 1
-export const nan =  (): Signature<'nan',  number> => (a) => NaN
-export const re =   (): Signature<'re',   number> => (a) => a
-
-$reflect!([zero, one, nan, re])
+export const zero: Signature<'zero', number> = (a) => 0
+export const one:  Signature<'one',  number> = (a) => 1
+export const nan:  Signature<'nan',  number> = (a) => NaN
+export const re:   Signature<'re',   number> = (a) => a

src/plugins/typeInferPlugin.ts

@@ -0,0 +1,84 @@
+import ts from 'typescript'
+
+const transformer: ts.TransformerFactory<ts.SourceFile> = context => {
+  // TODO: get a reference to the program instance that the plugin is running in instead of creating a new program?
+  const program = ts.createProgram([],  {})
+  const checker = program.getTypeChecker()
+
+  return sourceFile => {
+    const visitor = (node: ts.Node): ts.Node => {
+      // we're looking for a function call like $reflect(deps => ...)
+      // @ts-ignore
+      if (ts.isCallExpression(node) && ts.isIdentifier(node.expression) && node.expression.escapedText === '$reflect') {
+        console.log('PLUGIN: FOUND AN OCCURRENCE OF $reflect')
+        // console.log('PARENT')
+        // console.log(node)
+
+        // TODO: validate that argNode is an ArrowFunction
+        // @ts-ignore
+        const argNode = node.arguments[0]
+        // @ts-ignore
+        const returnType = argNode.type.getText(sourceFile)
+        console.log('PLUGIN: RETURN TYPE')
+        console.log(returnType)
+        // (a: number) => number
+
+        // @ts-ignore
+        const paramNode = argNode.parameters[0]
+        const paramTypeSrc = paramNode.type.getText(sourceFile)
+        console.log('PLUGIN: PARAM TYPE SRC', paramTypeSrc)
+        // {
+        //   multiply: (a: number, b: number) => number,
+        //   unaryMinus: (x: number) => number, // just for the experiment
+        // }
+
+        // WIP
+        // @ts-ignore
+        const type = checker.getTypeAtLocation(paramNode)
+        const paramType = checker.typeToString(type, undefined, ts.TypeFormatFlags.InTypeAlias)
+        // const paramType = checker.typeToString(type)
+        // TDOO: get checker.getTypeOfSymbolAtLocation(symbol, symbol.valueDeclaration)
+        console.log('PLUGIN: PARAM TYPE STRING', paramType)
+        // { multiply: (a: number, b: number) => number; unaryMinus: (x: number) => number; }
+
+
+        // WIP
+        // For a function definition
+        // const signature = checker.getResolvedSignature(node);
+        // if (signature != null) {
+        //   // outputs -- (Ctor: Ctor<Bar>): void
+        //   console.log(signature)
+        //   console.log('TEST 1', checker.signatureToString(signature));
+        //   // @ts-ignore
+        //   // console.log('TEST 2', checker.getResolvedSignatureForStringLiteralCompletions(node));
+        //   const params = signature.getParameters();
+        //   for (const param of params) {
+        //     const type = checker.getTypeOfSymbolAtLocation(param, node);
+        //     // outputs -- Ctor<Bar>
+        //     console.log('TEST 3', checker.typeToString(type));
+        //   }
+        // }
+
+        // WIP
+        const type1 = checker.getTypeAtLocation(paramNode)
+        const type2 = checker.getApparentType(type1)
+        const typeStr = checker.typeToString(type2, undefined, ts.TypeFormatFlags.InTypeAlias)
+        console.log('PLUGIN: RESOLVED TYPE ARGUMENT', typeStr) // TODO: not yet working
+
+        const depsAndReturnType = `{ deps: ${paramType}; return: ${returnType} }`
+
+        // Now we insert a second argument to the $reflect function call: a string with the types
+        // @ts-ignore
+        node.arguments.push(ts.factory.createStringLiteral(depsAndReturnType))
+
+        return node
+      }
+
+      return ts.visitEachChild(node, visitor, context)
+    }
+
+    return ts.visitNode(sourceFile, visitor)
+  }
+}
+
+export default transformer

tsconfig.json

@@ -1,12 +1,15 @@
 {
     "compilerOptions": {
-        "target": "esnext",
+        "target": "ES2022",
         "rootDir": "./src",
         "outDir": "./build",
-        "moduleResolution": "nodenext",
-        "plugins": [ {
-            "transform": "ts-macros/dist/type-resolve",
-            "transformProgram": true
-        } ]
+        "esModuleInterop": true,
+        "allowJs": false,
+        "noImplicitAny": false,
+        "moduleResolution": "Node",
+        "plugins": [{
+            "transform": "./src/plugins/typeInferPlugin.ts",
+            "type": "raw"
+        }]
     }
 }