Crate yash_arith 

This crate implements shell arithmetic expansion.

Arithmetic expansion evaluates an expression that may contain some operators that perform basic maths. The expression is given as a string and parsed like an expression in C. The expression can include variables that interact with the environment.

To evaluate an expression, you call the eval() function with a string and an environment.

use std::collections::HashMap;
use yash_arith::{eval, Value};
let mut env = HashMap::new();
env.insert("a".to_owned(), "2".to_owned());
let result = eval("1 + a", &mut env);
assert_eq!(result, Ok(Value::Integer(3)));

Structs

Config

Configuration for arithmetic expansion

Error

Description of an error that occurred during expansion

Enums

ErrorCause

Cause of an arithmetic expansion error

EvalError

Cause of an evaluation error

PortabilityError

Cause of an error because an expression contains a non-portable construct

SyntaxError

Cause of a syntax error

TokenError

Cause of a tokenization error

Value

Result of evaluating an expression

Traits

Env

Interface for accessing variables during evaluation

Functions

eval

Performs arithmetic expansion

eval_with_config

Performs arithmetic expansion with the specified configuration.