#string #expression #evaluation

shroom

A library for evaluating strings as expressions. This is an experimental version, the crate is unstable and most of the features are yet to be tested.

1 unstable release

0.0.1 Mar 17, 2019

#77 in #evaluation

GPL-3.0-only

100KB
2.5K SLoC

Shroom

A library for evaluating strings as expressions.
This is an experimental version. The crate is unstable and most of the features are yet to be tested.

Example usage:

// construct a new shroom instance
let shrm = Shroom::new();

// `eval` returns a `Result` containing a shroom primitive value on success
// or an error message on fail.
// A shroom primitive value can be an integer, a floating point number, a boolean value or a string.
// Calling `unwrap_int` on a primitive value returns the value as i64 or panics if it is not an integer.
let result = shrm.eval("2 + 3 * 4").unwrap().unwrap_int();

println!("2 + 3 * 4 = {}", result);

Output:

2 + 3 * 4 = 14

A shroom expression can contain decimal, hexadecimal (with prefix 0x), octal (0o) and binary (0b) integers, floating point numbers (basic decimal and scientific notation), boolean values (true or false), strings (enclosed in ") and the following binary operators:

  • + - * / ** % : basic arithmetic operations, exponentiation and remainder
  • & | ^ << >> : bitwise operations
  • > < >= <= != == : comparisons
  • && || : logical operations + can be used for string concatenation

Dependencies

~4MB
~89K SLoC