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use std::{os, ptr, cmp};
use super::*;
impl FromLisp<'_> for String {
#[cfg(not(feature = "utf-8-validation"))]
fn from_lisp(value: Value<'_>) -> Result<Self> {
let bytes = value.env.string_bytes(value)?;
unsafe { Ok(String::from_utf8_unchecked(bytes)) }
}
#[cfg(feature = "utf-8-validation")]
fn from_lisp(value: Value<'_>) -> Result<Self> {
let bytes = value.env.string_bytes(value)?;
Ok(String::from_utf8(bytes).unwrap())
}
}
impl IntoLisp<'_> for &str {
fn into_lisp(self, env: &Env) -> Result<Value<'_>> {
let bytes = self.as_bytes();
let len = bytes.len();
let ptr = bytes.as_ptr();
unsafe_raw_call_value!(env, make_string, ptr as *const os::raw::c_char, len as isize)
}
}
impl IntoLisp<'_> for &String {
fn into_lisp(self, env: &Env) -> Result<Value<'_>> {
self.as_str().into_lisp(env)
}
}
impl IntoLisp<'_> for String {
fn into_lisp(self, env: &Env) -> Result<Value<'_>> {
self.as_str().into_lisp(env)
}
}
impl<'e> Value<'e> {
pub fn copy_string_contents(self, buffer: &mut [u8]) -> Result<&[u8]> {
let env = self.env;
let ptr = buffer.as_mut_ptr() as *mut os::raw::c_char;
let max_len = buffer.len();
let mut len = max_len as isize;
match unsafe_raw_call!(env, copy_string_contents, self.raw, ptr, &mut len) {
Ok(false) => panic!("Emacs failed to copy string but did not raise a signal"),
Err(x) => Err(x),
_ => {
let n = cmp::min(max_len, len as usize) - 1;
Ok(&buffer[0..n])
}
}
}
}
impl Env {
fn string_bytes(&self, value: Value<'_>) -> Result<Vec<u8>> {
let mut len: isize = 0;
let mut bytes = unsafe {
let copy_string_contents = raw_fn!(self, copy_string_contents);
let ok: bool = self.handle_exit(copy_string_contents(
self.raw,
value.raw,
ptr::null_mut(),
&mut len,
))?;
if !ok {
panic!("Emacs failed to give string's length but did not raise a signal");
}
let mut bytes = vec![0u8; len as usize];
let ok: bool = self.handle_exit(copy_string_contents(
self.raw,
value.raw,
bytes.as_mut_ptr() as *mut os::raw::c_char,
&mut len,
))?;
if !ok {
panic!("Emacs failed to copy string but did not raise a signal");
}
bytes
};
strip_trailing_zero_bytes(&mut bytes);
Ok(bytes)
}
}
fn strip_trailing_zero_bytes(bytes: &mut Vec<u8>) {
let mut len = bytes.len();
while len > 0 && bytes[len - 1] == 0 {
bytes.pop();
len -= 1;
}
}