fix bugs in PausedPrologStream
use crate::machine::machine_indices::*;
use crate::machine::machine_state::*;
-use std::cmp::{min, Ordering};
+use std::cmp::Ordering;
use std::cell::RefCell;
use std::error::Error;
use std::fmt;
@@ -110,7 +110,7 @@ fn parser_top_to_bytes(mut buf: Vec<io::Result<char>>) -> io::Result<Vec<u8>> {
/* all these streams are closed automatically when the instance is
* dropped. */
-pub enum StreamInstance {
+enum StreamInstance {
Bytes(Cursor<Vec<u8>>),
InputFile(ClauseName, File),
OutputFile(ClauseName, File, bool), // File, append.
@@ -129,16 +129,20 @@ fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
StreamInstance::PausedPrologStream(ref mut put_back, ref mut stream) => {
let mut index = 0;
- while index < min(buf.len(), put_back.len()) {
- let b = put_back.pop().unwrap();
+ while index < buf.len() {
+ if let Some(b) = put_back.pop() {
buf[index] = b;
index += 1;
+ } else {
+ break;
+ }
}
if index == buf.len() {
Ok(buf.len())
} else {
stream.read(&mut buf[index ..])
+ .map(|bytes_read| bytes_read + index)
}
}
StreamInstance::InputFile(_, ref mut file) => {
