bendns' repos / mindus
mindustry logic execution, map- and schematic- parsing and rendering
use slice take
Browse Source
bendn 2024-01-23
parent 464801b · commit b91c780
Diffstat
-rw-r--r--mindus/src/data/mod.rs74
-rw-r--r--mindus/src/lib.rs1
2 files changed, 24 insertions, 51 deletions
diff --git a/mindus/src/data/mod.rs b/mindus/src/data/mod.rs
index c6c3743..0ad80a1 100644
--- a/mindus/src/data/mod.rs
+++ b/mindus/src/data/mod.rs
@@ -38,16 +38,7 @@ macro_rules! make_read {
($name:ident, $type:ty) => {
pub fn $name(&mut self) -> Result<$type, ReadError> {
const LEN: usize = std::mem::size_of::<$type>();
- if self.data.len() < LEN {
- return Err(ReadError::Underflow {
- need: LEN,
- have: self.data.len(),
- });
- }
- let mut output = [0u8; LEN];
- output.copy_from_slice(&self.data[..LEN]);
- self.data = &self.data[LEN..];
- self.read += LEN;
+ let output = self.readN::<LEN>()?;
Ok(<$type>::from_be_bytes(output))
}
};
@@ -75,47 +66,36 @@ impl<'d> DataRead<'d> {
make_read!(read_f64, f64);
pub fn read_utf(&mut self) -> Result<&'d str, ReadError> {
- if self.data.len() < 2 {
- return Err(ReadError::Underflow {
- need: 2,
- have: self.data.len(),
- });
- }
let len = self.read_u16()?;
- let end = len as usize;
- if self.data.len() < end {
- return Err(ReadError::Underflow {
- need: end,
- have: self.data.len(),
- });
- }
- let result = std::str::from_utf8(&self.data[..end])?;
- self.data = &self.data[end..];
- self.read += end;
+ let result = std::str::from_utf8(&self.eat(len as usize)?)?;
Ok(result)
}
- pub fn read_bytes(&mut self, dst: &mut [u8]) -> Result<(), ReadError> {
- if self.data.len() < dst.len() {
- return Err(ReadError::Underflow {
- need: dst.len(),
+ pub fn eat(&mut self, n: usize) -> Result<&'d [u8], ReadError> {
+ self.data
+ .take(..n)
+ .ok_or(ReadError::Underflow {
+ need: n,
have: self.data.len(),
- });
- }
- dst.copy_from_slice(&self.data[..dst.len()]);
- self.data = &self.data[dst.len()..];
- self.read += dst.len();
+ })
+ .inspect(|_| self.read += n)
+ }
+
+ #[allow(non_snake_case)]
+ pub fn readN<const N: usize>(&mut self) -> Result<[u8; N], ReadError> {
+ self.eat(N).map(|x| x.try_into().unwrap())
+ }
+
+ pub fn read_bytes(&mut self, dst: &mut [u8]) -> Result<(), ReadError> {
+ dst.copy_from_slice(self.eat(dst.len())?);
Ok(())
}
pub fn skip(&mut self, n: usize) -> Result<(), ReadError> {
- if self.data.len() < n {
- return Err(ReadError::Underflow {
- need: n,
- have: self.data.len(),
- });
- }
- self.data = &self.data[n..];
+ self.data = self.data.get(n..).ok_or(ReadError::Underflow {
+ need: n,
+ have: self.data.len(),
+ })?;
self.read += n;
Ok(())
}
@@ -160,15 +140,7 @@ impl<'d> DataRead<'d> {
}
pub fn read_vec(&mut self, dst: &mut Vec<u8>, len: usize) -> Result<(), ReadError> {
- if self.data.len() < len {
- return Err(ReadError::Underflow {
- need: len,
- have: self.data.len(),
- });
- }
- dst.extend_from_slice(&self.data[..len]);
- self.data = &self.data[len..];
- self.read += len;
+ dst.extend_from_slice(self.eat(len)?);
Ok(())
}
diff --git a/mindus/src/lib.rs b/mindus/src/lib.rs
index dacdc6b..0388762 100644
--- a/mindus/src/lib.rs
+++ b/mindus/src/lib.rs
@@ -4,6 +4,7 @@
const_trait_impl,
const_option,
derive_const,
+ slice_take,
let_chains,
effects
)]