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use std::{fmt::Display, ops::Deref};
/// Adds utility methods to the `Option<T>` type.
pub trait OptionExtension<T> {
/// Combines two Options into one using a custom closure.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a = Some(5.0);
/// let b = Some(10.0);
///
/// let sum = |a, b| { a + b };
/// let sub = |a, b| { a - b };
/// let mul = |a, b| { a * b };
/// let div = |a, b| { a / b };
///
/// assert_eq!(a.combine_with(b, sum), Some(15.0));
/// assert_eq!(a.combine_with(b, sub), Some(-5.0));
/// assert_eq!(a.combine_with(b, mul), Some(50.0));
/// assert_eq!(a.combine_with(b, div), Some(0.5));
/// ```
fn combine_with<U, R, F>(self, other: Option<U>, f: F) -> Option<R>
where
F: Fn(T, U) -> R;
/// Combines two Options using the Addition (`+`) operator.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a = Some(5);
/// let b = Some(10);
///
/// assert_eq!(a.combine_with_sum(b), Some(15));
/// ```
fn combine_with_sum<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Add<U, Output = R>;
/// Combines two Options using the Subtraction (`-`) operator.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a = Some(5);
/// let b = Some(10);
///
/// assert_eq!(a.combine_with_sub(b), Some(-5));
/// ```
fn combine_with_sub<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Sub<U, Output = R>;
/// Combines two Options using the Multiplication (`*`) operator.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a = Some(5);
/// let b = Some(10);
///
/// assert_eq!(a.combine_with_mul(b), Some(50));
/// ```
fn combine_with_mul<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Mul<U, Output = R>;
/// Combines two Options using the Division (`/`) operator.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a = Some(50);
/// let b = Some(10);
///
/// assert_eq!(a.combine_with_div(b), Some(5));
/// ```
fn combine_with_div<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Div<U, Output = R>;
/// Converts `Option<T>` to a `String`, with safe float truncation prevention.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a: Option<&str> = Some("foo bar");
/// let b: Option<u16> = Some(50);
/// let c: Option<f64> = Some(10.00);
/// let d: Option<f64> = Some(10.700);
/// let e: Option<f32> = Some(0.0);
/// let f: Option<f32> = Some(0.00000);
/// let g: Option<usize> = None;
///
/// assert_eq!(a.to_string(), "foo bar");
/// assert_eq!(b.to_string(), "50");
/// assert_eq!(c.to_string(), "10.0");
/// assert_eq!(d.to_string(), "10.7");
/// assert_eq!(e.to_string(), "0.0");
/// assert_eq!(f.to_string(), "0.0");
/// assert_eq!(g.to_string(), "");
/// ```
fn to_string(&self) -> String;
/// Parses an `Option<T>` into an `Option<U>` after stripping whitespace.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let a: Option<u64> = Some(56);
/// let b: Option<&str> = Some(" 56 ");
/// let c: Option<&str> = Some(" foo bar \n");
/// let d: Option<String> = Some("379.32000".to_string());
/// let e: Option<String> = Some("379.32 ".to_string());
///
/// let result_a: Option<u8> = a.parse_opt();
/// let result_b: Option<u8> = b.parse_opt();
/// let result_c: Option<String> = c.parse_opt();
/// let result_d: Option<f32> = d.parse_opt();
/// let result_e: Option<f64> = e.parse_opt();
/// let result_f: Option<u64> = e.parse_opt();
///
/// assert_eq!(result_a, Some(56));
/// assert_eq!(result_b, Some(56));
/// assert_eq!(result_c, Some("foo bar".to_string()));
/// assert_eq!(result_d, Some(379.32));
/// assert_eq!(result_e, Some(379.32));
/// assert_eq!(result_f, None);
/// ```
fn parse_opt<U>(&self) -> Option<U>
where
U: std::str::FromStr;
/// Retains only ASCII digit characters from an `Option<T>`.
///
/// # Examples
///
/// ```
/// use claudiofsr_lib::OptionExtension;
///
/// let opt_none: Option<&str> = None;
/// assert_eq!(opt_none.retain_only_digits(), None);
///
/// let opt_mixed: Option<&str> = Some("abc123-def;!456 @");
/// assert_eq!(opt_mixed.retain_only_digits(), Some("123456".to_string()));
///
/// let opt_digits: Option<String> = Some("0123456789".to_string());
/// assert_eq!(opt_digits.retain_only_digits(), Some("0123456789".to_string()));
///
/// let opt_letters: Option<&str> = Some("abcdefg");
/// assert_eq!(opt_letters.retain_only_digits(), None);
/// ```
fn retain_only_digits(&self) -> Option<String>
where
T: Deref<Target = str>;
}
impl<T> OptionExtension<T> for Option<T>
where
T: Display,
{
#[inline]
fn combine_with<U, R, F>(self, other: Option<U>, f: F) -> Option<R>
where
F: Fn(T, U) -> R,
{
// Zips self with another Option.
// If self is Some(x) and other is Some(y), this method returns Some((x, y)).
// Otherwise, None is returned.
self.zip(other).map(|(x, y)| f(x, y))
}
#[inline]
fn combine_with_sum<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Add<U, Output = R>,
{
self.combine_with(other, |a, b| a + b)
}
#[inline]
fn combine_with_sub<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Sub<U, Output = R>,
{
self.combine_with(other, |a, b| a - b)
}
#[inline]
fn combine_with_mul<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Mul<U, Output = R>,
{
self.combine_with(other, |a, b| a * b)
}
#[inline]
fn combine_with_div<U, R>(self, other: Option<U>) -> Option<R>
where
T: std::ops::Div<U, Output = R>,
{
self.combine_with(other, |a, b| a / b)
}
fn to_string(&self) -> String {
match self {
Some(type_t) => {
let type_name = std::any::type_name::<T>();
if (type_name == "f32" || type_name == "f64")
&& let Ok(float_64) = type_t.to_string().parse::<f64>()
&& float_64.trunc() == float_64
{
return format!("{float_64:.1}");
}
type_t.to_string()
}
None => String::new(),
}
}
#[inline]
fn parse_opt<U>(&self) -> Option<U>
where
U: std::str::FromStr,
{
self.as_ref()
.and_then(|entry| entry.to_string().trim().parse::<U>().ok())
}
#[inline]
fn retain_only_digits(&self) -> Option<String>
where
T: Deref<Target = str>,
{
let text = self.as_deref()?;
let digits: String = text.chars().filter(char::is_ascii_digit).collect();
(!digits.is_empty()).then_some(digits)
}
}
#[cfg(test)]
mod options_tests {
use super::*;
/// `cargo test -- --show-output retain_only_digits`
#[test]
fn retain_only_digits_empty_string() {
let opt_str: Option<&str> = None;
assert_eq!(opt_str.retain_only_digits(), None);
}
#[test]
fn retain_only_digits_non_digit_characters() {
let opt_str: Option<&str> = Some("abc123-def;!456@ ");
assert_eq!(opt_str.retain_only_digits(), Some("123456".to_string()));
}
#[test]
fn retain_only_digits_all_digits() {
let opt_str: Option<&str> = Some("0123456789");
assert_eq!(opt_str.retain_only_digits(), Some("0123456789".to_string()));
}
#[test]
fn retain_only_digits_no_digits() {
let opt_str: Option<&str> = Some("abcdefg");
assert_eq!(opt_str.retain_only_digits(), None);
}
}