digitalmars.D.learn - How to automatically generate function overloads
I'm porting over my linear algebra library from C++, and I have a bunch of functions that work on both scalars and vectors. The vector versions just apply the scalar function to every element of the vector, for example: ```D float clamp01(float x) { return x < 0 ? 0 : (x > 1 ? 1 : x); } float[N] clamp01(size_t N)(float[N] vec) { float[N] result; static foreach (i; 0 .. N) result[i] = clamp01(vec[i]); return result; } ``` And this is great, I don't have to write the same function for different array lengths. But I still have like 30-ish of these functions and I would like to generate the array overload automatically from the scalar overload. So I would like something like a mixin, that I can use like this: ```D mixin Vectorize_Unary_Function!clamp01; // Generates the code above. mixin Vectorize_Unary_Function!floor; mixin Vectorize_Unary_Function!ceil; ... ``` It doesn't have to be a mixin like this. I don't really care what it is as long as it works :) How could I do this?
May 04 2021
On Tuesday, 4 May 2021 at 11:00:42 UTC, Blatnik wrote:How could I do this?I've already tried this: ```D mixin template Vectorize_Unary_Function(alias Function) { float[N] Function(size_t N)(float[N] vec) { float[N] result; static foreach (i; 0 .. N) result[i] = Function(vec[i]); return result; } } ``` But it didn't work. ```D mixin Vectorize_Unary_Function!clamp01; float[2] vec = [1, 2]; float[2] clamped = clamp01(vec); // Error ``` I think it actually declared a function called "Function" instead of calling it "clamp01" like the alias I passed in.
May 04 2021
On Tuesday, 4 May 2021 at 11:00:42 UTC, Blatnik wrote:I'm porting over my linear algebra library from C++, and I have a bunch of functions that work on both scalars and vectors. The vector versions just apply the scalar function to every element of the vector, for example: ```D float clamp01(float x) { return x < 0 ? 0 : (x > 1 ? 1 : x); } float[N] clamp01(size_t N)(float[N] vec) { float[N] result; static foreach (i; 0 .. N) result[i] = clamp01(vec[i]); return result; } ``` And this is great, I don't have to write the same function for different array lengths. But I still have like 30-ish of these functions and I would like to generate the array overload automatically from the scalar overload. So I would like something like a mixin, that I can use like this: ```D mixin Vectorize_Unary_Function!clamp01; // Generates the code above. mixin Vectorize_Unary_Function!floor; mixin Vectorize_Unary_Function!ceil; ... ``` It doesn't have to be a mixin like this. I don't really care what it is as long as it works :) How could I do this?```D float clamp01(float x) { return x < 0 ? 0 : (x > 1 ? 1 : x); } template Vectorize_Unary_Function(alias fun) { float[N] Vectorize_Unary_Function(size_t N)(float[N] vec) { float[N] result; static foreach (i; 0 .. N) result[i] = fun(vec[i]); return result; } } alias clamp01 = Vectorize_Unary_Function!clamp01; void main() { float[5] vec = [1,2,3,4,5]; float[5] other = clamp01(vec); writeln(vec); writeln(other); } ``` Not exactly what you were asking for but I hope it works, tricky part is I'm not sure how to generate the function name without string mixins so that's why I used alias instead.
May 04 2021
On Tuesday, 4 May 2021 at 11:21:20 UTC, Zone wrote:```D template Vectorize_Unary_Function(alias fun) { float[N] Vectorize_Unary_Function(size_t N)(float[N] vec) { float[N] result; static foreach (i; 0 .. N) result[i] = fun(vec[i]); return result; } } alias clamp01 = Vectorize_Unary_Function!clamp01; ``` Not exactly what you were asking for but I hope it works, tricky part is I'm not sure how to generate the function name without string mixins so that's why I used alias instead.Awesome, this does exactly what I wanted. Thanks for the help! :)
May 04 2021