use crate::Context;
use crate::alloc::Vec;
use crate::json::error::ErrorMessage;
use crate::json::parser::{Parser, StringReference};
use crate::reader::SliceUnderflow;
use super::string::SliceAccess;
pub struct SliceParser<'de> {
pub(crate) slice: &'de [u8],
pub(crate) index: usize,
}
impl<'de> SliceParser<'de> {
#[inline]
pub(crate) fn new(slice: &'de [u8]) -> Self {
Self { slice, index: 0 }
}
}
impl<'de> Parser<'de> for SliceParser<'de> {
type Mut<'this>
= &'this mut SliceParser<'de>
where
Self: 'this;
type TryClone = SliceParser<'de>;
#[inline]
fn borrow_mut(&mut self) -> Self::Mut<'_> {
self
}
#[inline]
fn try_clone(&self) -> Option<Self::TryClone> {
Some(SliceParser {
slice: self.slice,
index: self.index,
})
}
#[inline]
fn parse_string_inner<'scratch, C>(
&mut self,
cx: C,
validate: bool,
scratch: &'scratch mut Vec<u8, C::Allocator>,
start: &C::Mark,
) -> Result<StringReference<'de, 'scratch>, C::Error>
where
C: Context,
{
let mut access = SliceAccess::new(cx, self.slice, self.index);
let out = access.parse_string(validate, start, scratch);
self.index = access.index;
out
}
#[inline]
fn skip_string_inner<C>(&mut self, cx: C) -> Result<(), C::Error>
where
C: Context,
{
let mut access = SliceAccess::new(cx, self.slice, self.index);
let out = access.skip_string();
self.index = access.index;
out
}
#[inline]
fn skip<C>(&mut self, cx: C, n: usize) -> Result<(), C::Error>
where
C: Context,
{
let outcome = self.index.wrapping_add(n);
if outcome > self.slice.len() || outcome < self.index {
return Err(cx.custom(SliceUnderflow::new(n, self.slice.len() - self.index)));
}
self.index = outcome;
cx.advance(n);
Ok(())
}
#[inline]
fn read<C>(&mut self, cx: C, buf: &mut [u8]) -> Result<(), C::Error>
where
C: Context,
{
let outcome = self.index.wrapping_add(buf.len());
if outcome > self.slice.len() || outcome < self.index {
return Err(cx.custom(SliceUnderflow::new(
buf.len(),
self.slice.len() - self.index,
)));
}
buf.copy_from_slice(&self.slice[self.index..outcome]);
self.index = outcome;
cx.advance(buf.len());
Ok(())
}
#[inline]
fn skip_whitespace<C>(&mut self, cx: C)
where
C: Context,
{
while matches!(
self.slice.get(self.index),
Some(b' ' | b'\n' | b'\t' | b'\r')
) {
self.index = self.index.wrapping_add(1);
cx.advance(1);
}
}
#[inline]
fn peek(&mut self) -> Option<u8> {
self.slice.get(self.index).copied()
}
fn parse_f32<C>(&mut self, cx: C) -> Result<f32, C::Error>
where
C: Context,
{
let Some((value, read)) = crate::dec2flt::dec2flt(&self.slice[self.index..]) else {
return Err(cx.message(ErrorMessage::ParseFloat));
};
self.index += read;
cx.advance(read);
Ok(value)
}
fn parse_f64<C>(&mut self, cx: C) -> Result<f64, C::Error>
where
C: Context,
{
let Some((value, read)) = crate::dec2flt::dec2flt(&self.slice[self.index..]) else {
return Err(cx.message(ErrorMessage::ParseFloat));
};
self.index += read;
cx.advance(read);
Ok(value)
}
}