Macro tgraph::func

macro_rules! func {
    (|$x:ident| $code:expr) => { ... };
    ($e:expr) => { ... };
    ($x:ident -> $code:expr) => { ... };
    ($x:ident [$xt:ty] -> $code:expr) => { ... };
    ($x:ident [$xt:ty] -> $code:expr => [$yt:ty]) => { ... };
    ($x:ident -> $code:expr => [$yt:ty]) => { ... };
}

A handy macro for creating Function instances easier.

This macro has three possible syntaxes for defining functions: closure-like, raw and arrow. It casts the created closure to fn($x_type) -> $y_type to ensure that they have the same type signature (needed for usage in MultiGraph ).

The first of them is just the same syntax as a simple closure, without possible type annotations, as the type is to be set to f64. On the other hand, you have the raw syntax, which allows basically anything, included a typed closure, but casting to an fn(T) -> U is required when using MultiGraph so all functions have the same signature. An example usage is the following:

use tgraph::{MultiGraph, func};

fn main() {
  MultiGraph::new_screen(vec![
    func!(|x| f64::sin(x/2f64).abs() * 4f64),
    func!(|x: f64| -> f64 {x.ln()} as fn(f64) -> f64),
  ]).draw();
}