Crate interpol

interpol

String interpolation macros for rust

Usage

Macros provided by this crate correspond to std's formatting macros (format,print, println, eprint, eprintln, ...).

You can use these macros just same as std's ones.

use interpol::println;

let a = 3;
let b = 4;
println!("{a} times {b} is {a * b}."); // => "3 times 4 is 12."

It is also able to specify formatting option:

use interpol::println;

let pi = 3.14;
println!("{pi:.10}"); // => "3.1400000000"
println!("{123:x}");  // => "7b"

let v = vec![1, 2, 3];
println!("{v:?}");     // => "[1, 2, 3]"

Correctly handles unicode characters:

use interpol::println;

let world = "世界";
println!("ハロー {world}"); // => "ハロー 世界"

It is able to write expressions:

use interpol::println;

println!("PI = {std::f64::consts::PI:.10}");
    // => "PI = 3.1415926536"

println!("PI = { 1.0_f64.atan() * 4.0 :.10}");
    // => "PI = 3.1415926536"

You can also write nested block expressions:

use interpol::println;

println!("{ { let t = 123; t * t } }"); // => "15129"

println!("{{ let t = 123; t * t }}");
    // "{{" and "}}" is escaped so the result is:
    // => "{ let t = 123; t * t }"

Macros

eprint
eprintln
format
print
println
write
writeln