2 releases
0.1.1 | Aug 1, 2021 |
---|---|
0.1.0 | Aug 1, 2021 |
#126 in Parser tooling
634 downloads per month
Used in 9 crates
(5 directly)
35KB
660 lines
peekread
This crate allows you to take an arbitrary Read
stream and 'peek ahead'
into the stream without consuming the original stream. This is done through the
PeekRead
trait which has the method peek
. When this method is called it
returns a new PeekCursor
object implementing Read
, BufRead
and Seek
that
allows you to read from the stream without affecting the original stream.
The PeekRead
trait is directly implemented on a select few types, but for most
you will have to wrap your type in a SeekPeekReader
or BufPeekReader
that
implements the peeking behavior using respectively seeking or buffering.
Please refer to the the documentation for more information.
The minimum required stable Rust version for peekread
is 1.31.0. To start using
peekread
add the following to your Cargo.toml
:
[dependencies]
peekread = "0.1"
Example
A short example:
use peekread::{PeekRead, SeekPeekReader};
let mut f = SeekPeekReader::new(File::open("ambiguous")?);
// HTML is so permissive its parser never fails, so check for signature.
if f.starts_with("<!DOCTYPE") {
Ok(ParseResult::Html(parse_as_html(f)))
} else {
// Can pass PeekCursor to functions accepting T: Read without them
// having to be aware of peekread.
parse_as_jpg(f.peek()).map(ParseResult::Jpg)
.or_else(|_| parse_as_png(f.peek()).map(ParseResult::Png))
.or_else(|_| parse_as_gif(f.peek()).map(ParseResult::Gif))
.or_else(|_| parse_as_javascript(f.peek()).map(ParseResult::Js))
}
License
peekread
is released under the Zlib license, a permissive license. It is
OSI and FSF approved and GPL compatible.