use std::{
ops::{Deref, Range, RangeFrom, RangeTo},
str::{CharIndices, Chars},
};
use nom::{
Compare, CompareResult, InputIter, InputLength, InputTake, Needed, Slice, UnspecializedInput,
};
use swc_common::{comments::Comment, BytePos, Span};
use crate::ast::Text;
#[derive(Debug, Clone, Copy)]
pub struct Input<'i> {
start: BytePos,
end: BytePos,
src: &'i str,
}
impl<'a> From<&'a Comment> for Input<'a> {
fn from(c: &'a Comment) -> Self {
Self::new(c.span.lo, c.span.hi, &c.text)
}
}
impl<'i> Input<'i> {
pub const fn empty() -> Self {
Self::new(BytePos::DUMMY, BytePos::DUMMY, "")
}
pub const fn new(start: BytePos, end: BytePos, src: &'i str) -> Self {
Self { start, end, src }
}
#[inline(always)]
pub fn span(self) -> Span {
Span::new(self.start, self.end)
}
}
macro_rules! impl_slice {
($T:ident) => {
impl Slice<$T<usize>> for Input<'_> {
fn slice(&self, range: $T<usize>) -> Self {
let s = self.src.slice(range);
Self::new(self.start, self.start + BytePos(s.as_bytes().len() as _), s)
}
}
};
}
impl_slice!(Range);
impl_slice!(RangeFrom);
impl_slice!(RangeTo);
impl From<Input<'_>> for Text {
fn from(i: Input) -> Self {
Self {
span: Span::new(i.start, i.end),
value: i.src.into(),
}
}
}
impl InputTake for Input<'_> {
fn take(&self, count: usize) -> Self {
self.slice(..count)
}
fn take_split(&self, count: usize) -> (Self, Self) {
(self.slice(..count), self.slice(count..))
}
}
impl<'a> Compare<&'a str> for Input<'_> {
fn compare(&self, t: &'a str) -> CompareResult {
self.src.compare(t)
}
fn compare_no_case(&self, t: &'a str) -> CompareResult {
self.src.compare_no_case(t)
}
}
impl InputLength for Input<'_> {
fn input_len(&self) -> usize {
self.src.as_bytes().len()
}
}
impl UnspecializedInput for Input<'_> {}
impl<'a> InputIter for Input<'a> {
type Item = char;
type Iter = CharIndices<'a>;
type IterElem = Chars<'a>;
fn iter_indices(&self) -> Self::Iter {
self.src.iter_indices()
}
fn iter_elements(&self) -> Self::IterElem {
self.src.iter_elements()
}
fn position<P>(&self, predicate: P) -> Option<usize>
where
P: Fn(Self::Item) -> bool,
{
self.src.position(predicate)
}
fn slice_index(&self, count: usize) -> Result<usize, Needed> {
self.src.slice_index(count)
}
}
impl Deref for Input<'_> {
type Target = str;
fn deref(&self) -> &Self::Target {
self.src
}
}