gistfile1.txt

import macros



proc concreteType* (n:NimNode): NimNode{.compileTime.}=
    return case n.typeKind
    of ntyTypeDesc:
        n[1].concreteType
    else:
        n

macro implementing (f:stmt, body:stmt): expr =
    let ty = f.getType.concreteType
    assert ty.typeKind == ntyProc
    assert body.kind == nnkDo
    
    # return a function implementing `f`
    
    var params: seq[NimNode] = @[]
    for i in 1 .. high(body.params):
        let p = body.params[i]
        for ii in 0 .. len(p)-3:
            params.add p[ii]
    
    result = newProc(procKind = nnkLambda
    echo body.typekind
    echo body.treerepr
    echo ty.typekind
    echo ty.treerepr
    

import typetraits

type
    TFunc = proc(a,b: int): int

discard(implementing(TFunc) do (a,b):
    return a+b)