xprs 0.1.0

Xprs is a flexible and extensible mathematical expression parser and evaluator for Rust, designed for simplicity and ease of use.
Documentation 
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/* Crate imports */
use crate::token::Operator;

/// Constant representing no precedence.
pub const NO_PRECEDENCE: usize = 0;
/// Constant representing unary operator precedence.
pub const UNOP_PRECEDENCE: usize = 3;

/// Constant representing the precedence of implicit multiplication.
/// The actual value depends on the feature configuration.
#[cfg(feature = "pejmdas")]
const IMPLICIT_MULTIPLICATION_PRECEDENCE: usize = 3;
/// Constant representing the precedence of implicit multiplication.
/// The actual value depends on the feature configuration.
#[cfg(feature = "pemdas")]
const IMPLICIT_MULTIPLICATION_PRECEDENCE: usize = get_for_op(Operator::Times);

/// Utility constant representing the implicit multiplication operator + its precedence.
pub const IMPLICIT_MULTIPLICATION_INFO: (Operator, usize) =
    (Operator::Times, IMPLICIT_MULTIPLICATION_PRECEDENCE);

/// Retrieves the precedence value for a given operator.
pub const fn get_for_op(op: Operator) -> usize {
    match op {
        Operator::Plus | Operator::Minus => 1,
        Operator::Times | Operator::Divide | Operator::Modulo => 2,
        // uses `4` because `pejmdas` feature uses `3`
        Operator::Power => 4,
        Operator::Factorial => 5,
    }
}