A crate to format and print strings with an embedded rust expression, similar to f-string formatting in Python.

Examples

Using :? modifier. use expression_format::ex_format; let v = vec![1, 2, 3]; assert_eq!(ex_format!("v = {:?v}"), "v = [1, 2, 3]");

Using other modifiers (std:fmt for details). use expression_format::ex_format; // Space after format specs if it doesn't ends in ? assert_eq!(ex_format!(r#"Hello {:-<5 "x"}!"#), "Hello x----!"); assert_eq!(ex_format!("{:.5 12.3}"), "12.30000"); assert_eq!(ex_format!("{:#010x 27}!"), "0x0000001b!"); No support for * and $ parameters.

Printing the contents of fields. use expression_format::ex_format; let arg = ["ipsum", "sit"]; assert_eq!(ex_format!("lorem {arg[0]} dolor {arg[1]} amet"), "lorem ipsum dolor sit amet");

Short version of ex_format! with a complex expression. ``` use expression_format::short::exf;

asserteq!( exf!(r#"Hello { { // Space after the first { since {{ is an escape sequence. let first = "Wo"; let second = "rld"; let mut result = String::from(first); result.pushstr(second); result }}!"#), "Hello World!" ); ```

Print to standard output with a new line. ``` use expressionformat::short::expl; // Short name version of exprintln!

[derive(Debug)]

struct Point {x: i32, y: i32}

expl!("value of point = {:?Point {x: 1 + 2, y: 3 * 4 }}"); // stdout: value of point = Point { x: 3, y: 12 } ```

Escape brackets with {{ and }}. use expression_format::short::exf; let value = 10; assert_eq!(exf!("{{value}} = {value}"), "{value} = 10");