Crate expr

Example:

use expr::{Context, Parser};

let mut p = Parser::new();

let mut ctx = Context::default();
ctx.insert("two".to_string(), 2);

let three: i64 = p.eval("1 + two", &ctx).unwrap().as_number().unwrap();
assert_eq!(three, 3);

p.add_function("add", |c| {
  let mut sum = 0;
  for arg in c.args {
    sum += arg.as_number().unwrap();
  }
  Ok(sum.into())
});

let six: i64 = p.eval("add(1, two, 3)", &ctx).unwrap().as_number().unwrap();
assert_eq!(six, 6);

Macros

bail

Structs

Context

Parser

Main struct for parsing and evaluating expr programs

Program

A parsed expr program that can be run

Enums

Error

An error that can occur when parsing or evaluating an expr program

Rule

Value

Represents a data value as input or output to an expr program

Type Aliases

Result