rkgk/crates/haku/src/source.rs
liquidex 2595bf0d82 syntax v2
introduce a new, more ergonomic syntax for haku
not all features are implemented just yet. still missing:

- custom tags (non-True/False)
- color literals
- lists
2024-09-01 09:29:11 +02:00

56 lines
1.3 KiB
Rust

use core::{fmt, ops::Deref};
#[derive(Clone, Copy, PartialEq, Eq)]
pub struct Span {
pub start: u32,
pub end: u32,
}
impl Span {
pub fn new(start: u32, end: u32) -> Self {
Self { start, end }
}
pub fn slice<'a>(&self, source: &'a SourceCode) -> &'a str {
&source.code[self.start as usize..self.end as usize]
}
}
impl fmt::Debug for Span {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}..{}", self.start, self.end)
}
}
/// Source code string with a verified size limit.
/// An exact size limit is not enforced by this type - it only ensures the string isn't longer than
/// intended, to not stall the parser for an unexpected amount of time.
#[derive(Debug, PartialEq, Eq)]
#[repr(transparent)]
pub struct SourceCode {
code: str,
}
impl SourceCode {
pub fn limited_len(code: &str, max_len: u32) -> Option<&Self> {
if code.len() <= max_len as usize {
Some(Self::unlimited_len(code))
} else {
None
}
}
pub fn unlimited_len(code: &str) -> &Self {
// SAFETY: SourceCode is a transparent wrapper around str, so converting between them is safe.
unsafe { core::mem::transmute(code) }
}
}
impl Deref for SourceCode {
type Target = str;
fn deref(&self) -> &Self::Target {
&self.code
}
}