rhai/src/packages/iter_basic.rs
2021-06-29 21:58:05 +08:00

460 lines
14 KiB
Rust

use crate::dynamic::Variant;
use crate::{def_package, EvalAltResult, INT};
use std::ops::Range;
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
#[cfg(not(feature = "unchecked"))]
use num_traits::{CheckedAdd as Add, CheckedSub as Sub};
#[cfg(feature = "unchecked")]
use std::ops::{Add, Sub};
// Range iterator with step
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
struct StepRange<T>(T, T, T)
where
T: Variant + Copy + PartialOrd + Add<Output = T> + Sub<Output = T>;
impl<T> StepRange<T>
where
T: Variant + Copy + PartialOrd + Add<Output = T> + Sub<Output = T>,
{
pub fn new(from: T, to: T, step: T) -> Result<Self, Box<EvalAltResult>> {
#[cfg(not(feature = "unchecked"))]
if let Some(r) = from.checked_add(&step) {
if r == from {
return EvalAltResult::ErrorInFunctionCall(
"range".to_string(),
Default::default(),
EvalAltResult::ErrorArithmetic(
"step value cannot be zero".to_string(),
crate::Position::NONE,
)
.into(),
crate::Position::NONE,
)
.into();
}
}
Ok(Self(from, to, step))
}
}
impl<T> Iterator for StepRange<T>
where
T: Variant + Copy + PartialOrd + Add<Output = T> + Sub<Output = T>,
{
type Item = T;
fn next(&mut self) -> Option<T> {
if self.0 == self.1 {
None
} else if self.0 < self.1 {
#[cfg(not(feature = "unchecked"))]
let diff1 = if let Some(diff) = self.1.checked_sub(&self.0) {
diff
} else {
return None;
};
#[cfg(feature = "unchecked")]
let diff1 = self.1 - self.0;
let v = self.0;
#[cfg(not(feature = "unchecked"))]
let n = if let Some(num) = self.0.checked_add(&self.2) {
num
} else {
return None;
};
#[cfg(feature = "unchecked")]
let n = self.0 + self.2;
#[cfg(not(feature = "unchecked"))]
let diff2 = if let Some(diff) = self.1.checked_sub(&n) {
diff
} else {
return None;
};
#[cfg(feature = "unchecked")]
let diff2 = self.1 - n;
if diff2 >= diff1 {
None
} else {
self.0 = if n >= self.1 { self.1 } else { n };
Some(v)
}
} else {
#[cfg(not(feature = "unchecked"))]
let diff1 = if let Some(diff) = self.0.checked_sub(&self.1) {
diff
} else {
return None;
};
#[cfg(feature = "unchecked")]
let diff1 = self.0 - self.1;
let v = self.0;
#[cfg(not(feature = "unchecked"))]
let n = if let Some(num) = self.0.checked_add(&self.2) {
num
} else {
return None;
};
#[cfg(feature = "unchecked")]
let n = self.0 + self.2;
#[cfg(not(feature = "unchecked"))]
let diff2 = if let Some(diff) = n.checked_sub(&self.1) {
diff
} else {
return None;
};
#[cfg(feature = "unchecked")]
let diff2 = n - self.1;
if diff2 >= diff1 {
None
} else {
self.0 = if n <= self.1 { self.1 } else { n };
Some(v)
}
}
}
}
// Bit-field iterator with step
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
struct BitRange(INT, INT, usize);
const BITS: usize = std::mem::size_of::<INT>() * 8;
impl BitRange {
pub fn new(value: INT, from: INT, len: INT) -> Result<Self, Box<EvalAltResult>> {
let from = if from >= 0 {
let offset = from as usize;
#[cfg(not(feature = "unchecked"))]
if offset >= BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, crate::Position::NONE)
.into();
}
offset
} else {
#[cfg(not(feature = "unchecked"))]
if let Some(abs_from) = from.checked_abs() {
if (abs_from as usize) > BITS {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, crate::Position::NONE)
.into();
}
BITS - (abs_from as usize)
} else {
return EvalAltResult::ErrorBitFieldBounds(BITS, from, crate::Position::NONE)
.into();
}
#[cfg(feature = "unchecked")]
{
BITS - (from.abs() as usize)
}
};
let len = if len < 0 {
0
} else if from + (len as usize) > BITS {
BITS - from
} else {
len as usize
};
Ok(Self(value, 1 << from, len))
}
}
impl Iterator for BitRange {
type Item = bool;
fn next(&mut self) -> Option<Self::Item> {
let Self(value, mask, len) = *self;
if len == 0 {
None
} else {
let r = (value & mask) != 0;
self.1 <<= 1;
self.2 -= 1;
Some(r)
}
}
}
// String iterator over characters
#[derive(Debug, Clone, Hash, Eq, PartialEq)]
struct CharsStream(Vec<char>, usize);
impl CharsStream {
pub fn new(string: &str, from: INT, len: INT) -> Self {
if len <= 0 {
return Self(Default::default(), 0);
}
if from >= 0 {
return Self(
string
.chars()
.skip(from as usize)
.take(len as usize)
.collect(),
0,
);
}
#[cfg(not(feature = "unchecked"))]
return if let Some(abs_from) = from.checked_abs() {
let num_chars = string.chars().count();
let offset = if num_chars < (abs_from as usize) {
0
} else {
num_chars - (abs_from as usize)
};
Self(string.chars().skip(offset).take(len as usize).collect(), 0)
} else {
Self(string.chars().skip(0).take(len as usize).collect(), 0)
};
#[cfg(feature = "unchecked")]
return Self(
string
.chars()
.skip(from as usize)
.take(len as usize)
.collect(),
0,
);
}
}
impl Iterator for CharsStream {
type Item = char;
fn next(&mut self) -> Option<Self::Item> {
if self.1 >= self.0.len() {
None
} else {
let ch = self.0[self.1];
self.1 += 1;
Some(ch)
}
}
}
macro_rules! reg_range {
($lib:ident | $x:expr => $( $y:ty ),*) => {
$(
$lib.set_iterator::<Range<$y>>();
let _hash = $lib.set_native_fn($x, |from: $y, to: $y| Ok(from..to));
#[cfg(feature = "metadata")]
$lib.update_fn_metadata(_hash, &[
concat!("from: ", stringify!($y)),
concat!("to: ", stringify!($y)),
concat!("Iterator<Item=", stringify!($y), ">")
]);
)*
};
($lib:ident | step $x:expr => $( $y:ty ),*) => {
$(
$lib.set_iterator::<StepRange<$y>>();
let _hash = $lib.set_native_fn($x, |from: $y, to: $y, step: $y| StepRange::new(from, to, step));
#[cfg(feature = "metadata")]
$lib.update_fn_metadata(_hash, &[
concat!("from: ", stringify!($y)),
concat!("to: ", stringify!($y)),
concat!("step: ", stringify!($y)),
concat!("Iterator<Item=", stringify!($y), ">")
]);
)*
};
}
def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
reg_range!(lib | "range" => INT);
#[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))]
{
reg_range!(lib | "range" => i8, u8, i16, u16, i32, u32, i64, u64);
#[cfg(not(target_arch = "wasm32"))]
reg_range!(lib | "range" => i128, u128);
}
reg_range!(lib | step "range" => INT);
#[cfg(not(feature = "only_i32"))]
#[cfg(not(feature = "only_i64"))]
{
reg_range!(lib | step "range" => i8, u8, i16, u16, i32, u32, i64, u64);
#[cfg(not(target_arch = "wasm32"))]
reg_range!(lib | step "range" => i128, u128);
}
#[cfg(not(feature = "no_float"))]
{
use crate::FLOAT;
#[derive(Debug, Clone, Copy, PartialEq)]
struct StepFloatRange(FLOAT, FLOAT, FLOAT);
impl StepFloatRange {
pub fn new(from: FLOAT, to: FLOAT, step: FLOAT) -> Result<Self, Box<EvalAltResult>> {
#[cfg(not(feature = "unchecked"))]
if step == 0.0 {
return EvalAltResult::ErrorInFunctionCall("range".to_string(), "".to_string(),
EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), crate::Position::NONE).into(),
crate::Position::NONE,
).into();
}
Ok(Self(from, to, step))
}
}
impl Iterator for StepFloatRange {
type Item = FLOAT;
fn next(&mut self) -> Option<FLOAT> {
if self.0 == self.1 {
None
} else if self.0 < self.1 {
#[cfg(not(feature = "unchecked"))]
if self.2 < 0.0 {
return None;
}
let v = self.0;
let n = self.0 + self.2;
self.0 = if n >= self.1 { self.1 } else { n };
Some(v)
} else {
#[cfg(not(feature = "unchecked"))]
if self.2 > 0.0 {
return None;
}
let v = self.0;
let n = self.0 + self.2;
self.0 = if n <= self.1 { self.1 } else { n };
Some(v)
}
}
}
impl std::iter::FusedIterator for StepFloatRange {}
lib.set_iterator::<StepFloatRange>();
let _hash = lib.set_native_fn("range", |from, to, step| StepFloatRange::new(from, to, step));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["from: FLOAT", "to: FLOAT", "step: FLOAT", "Iterator<Item=FLOAT>"]);
}
#[cfg(feature = "decimal")]
{
use rust_decimal::Decimal;
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
struct StepDecimalRange(Decimal, Decimal, Decimal);
impl StepDecimalRange {
pub fn new(from: Decimal, to: Decimal, step: Decimal) -> Result<Self, Box<EvalAltResult>> {
#[cfg(not(feature = "unchecked"))]
if step.is_zero() {
return EvalAltResult::ErrorInFunctionCall("range".to_string(), "".to_string(),
EvalAltResult::ErrorArithmetic("step value cannot be zero".to_string(), crate::Position::NONE).into(),
crate::Position::NONE,
).into();
}
Ok(Self(from, to, step))
}
}
impl Iterator for StepDecimalRange {
type Item = Decimal;
fn next(&mut self) -> Option<Decimal> {
if self.0 == self.1 {
None
} else if self.0 < self.1 {
#[cfg(not(feature = "unchecked"))]
if self.2.is_sign_negative() {
return None;
}
let v = self.0;
let n = self.0 + self.2;
self.0 = if n >= self.1 { self.1 } else { n };
Some(v)
} else {
#[cfg(not(feature = "unchecked"))]
if self.2.is_sign_positive() {
return None;
}
let v = self.0;
let n = self.0 + self.2;
self.0 = if n <= self.1 { self.1 } else { n };
Some(v)
}
}
}
impl std::iter::FusedIterator for StepDecimalRange {}
lib.set_iterator::<StepDecimalRange>();
let _hash = lib.set_native_fn("range", |from, to, step| StepDecimalRange::new(from, to, step));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["from: Decimal", "to: Decimal", "step: Decimal", "Iterator<Item=Decimal>"]);
}
// Register string iterator
lib.set_iterator::<CharsStream>();
let _hash = lib.set_native_fn("chars", |string, from,len| Ok(CharsStream::new(string, from, len)));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["string: &str", "from: INT", "len: INT", "Iterator<Item=char>"]);
let _hash = lib.set_native_fn("chars", |string, from| Ok(CharsStream::new(string, from, INT::MAX)));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["string: &str", "from: INT", "Iterator<Item=char>"]);
let _hash = lib.set_native_fn("chars", |string| Ok(CharsStream::new(string, 0, INT::MAX)));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["string: &str", "Iterator<Item=char>"]);
// Register bit-field iterator
lib.set_iterator::<BitRange>();
let _hash = lib.set_native_fn("bits", |value, from, len| BitRange::new(value, from, len));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "from: INT", "len: INT", "Iterator<Item=bool>"]);
let _hash = lib.set_native_fn("bits", |value, from| BitRange::new(value, from, INT::MAX));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "from: INT", "Iterator<Item=bool>"]);
let _hash = lib.set_native_fn("bits", |value| BitRange::new(value, 0, INT::MAX));
#[cfg(feature = "metadata")]
lib.update_fn_metadata(_hash, &["value: INT", "Iterator<Item=bool>"]);
});