rhai/src/packages/iter_basic.rs
2020-10-19 23:49:01 +08:00

93 lines
2.2 KiB
Rust

use crate::any::Variant;
use crate::def_package;
use crate::parser::INT;
use crate::result::EvalAltResult;
use crate::stdlib::{
boxed::Box,
ops::{Add, Range},
};
fn get_range<T: Variant + Clone>(from: T, to: T) -> Result<Range<T>, Box<EvalAltResult>> {
Ok(from..to)
}
// Register range function with step
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
struct StepRange<T>(T, T, T)
where
for<'a> &'a T: Add<&'a T, Output = T>,
T: Variant + Clone + PartialOrd;
impl<T> Iterator for StepRange<T>
where
for<'a> &'a T: Add<&'a T, Output = T>,
T: Variant + Clone + PartialOrd,
{
type Item = T;
fn next(&mut self) -> Option<T> {
if self.0 < self.1 {
let v = self.0.clone();
self.0 = &v + &self.2;
Some(v)
} else {
None
}
}
}
fn get_step_range<T>(from: T, to: T, step: T) -> Result<StepRange<T>, Box<EvalAltResult>>
where
for<'a> &'a T: Add<&'a T, Output = T>,
T: Variant + Clone + PartialOrd,
{
Ok(StepRange::<T>(from, to, step))
}
macro_rules! reg_range {
($lib:expr, $x:expr, $( $y:ty ),*) => (
$(
$lib.set_iterator::<Range<$y>>();
$lib.set_fn_2($x, get_range::<$y>);
)*
)
}
macro_rules! reg_step {
($lib:expr, $x:expr, $( $y:ty ),*) => (
$(
$lib.set_iterator::<StepRange<$y>>();
$lib.set_fn_3($x, get_step_range::<$y>);
)*
)
}
def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
lib.set_iterator::<Range<INT>>();
lib.set_fn_2("range", get_range::<INT>);
#[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))]
{
reg_range!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64);
if cfg!(not(target_arch = "wasm32")) {
reg_range!(lib, "range", i128, u128);
}
}
lib.set_iterator::<StepRange<INT>>();
lib.set_fn_3("range", get_step_range::<INT>);
#[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))]
{
reg_step!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64);
if cfg!(not(target_arch = "wasm32")) {
reg_step!(lib, "range", i128, u128);
}
}
});