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-rw-r--r--vendor/winnow-0.4.7/examples/ndjson/main.rs113
1 files changed, 113 insertions, 0 deletions
diff --git a/vendor/winnow-0.4.7/examples/ndjson/main.rs b/vendor/winnow-0.4.7/examples/ndjson/main.rs
new file mode 100644
index 000000000..d81b6900f
--- /dev/null
+++ b/vendor/winnow-0.4.7/examples/ndjson/main.rs
@@ -0,0 +1,113 @@
+mod parser;
+
+use std::io::Read;
+
+use winnow::error::ErrMode;
+use winnow::error::Error;
+use winnow::error::Needed;
+use winnow::stream::Offset;
+
+fn main() -> Result<(), lexopt::Error> {
+ let args = Args::parse()?;
+ let input = args.input.ok_or_else(|| lexopt::Error::MissingValue {
+ option: Some("<PATH>".to_owned()),
+ })?;
+
+ let mut file = std::fs::File::open(&input).map_err(to_lexopt)?;
+
+ // Intentionally starting with a small buffer to make it easier to show `Incomplete` handling
+ let buffer_size = 10;
+ let min_buffer_growth = 100;
+ let buffer_growth_factor = 2;
+ let mut buffer = circular::Buffer::with_capacity(buffer_size);
+ loop {
+ let read = file.read(buffer.space()).map_err(to_lexopt)?;
+ eprintln!("read {}", read);
+ if read == 0 {
+ // Should be EOF since we always make sure there is `available_space`
+ assert_ne!(buffer.available_space(), 0);
+ assert_eq!(
+ buffer.available_data(),
+ 0,
+ "leftover data: {}",
+ String::from_utf8_lossy(buffer.data())
+ );
+ break;
+ }
+ buffer.fill(read);
+
+ loop {
+ let input = parser::Stream::new(std::str::from_utf8(buffer.data()).map_err(to_lexopt)?);
+ match parser::ndjson::<Error<parser::Stream>>(input) {
+ Ok((remainder, value)) => {
+ println!("{:?}", value);
+ println!();
+ // Tell the buffer how much we read
+ let consumed = input.offset_to(&remainder);
+ buffer.consume(consumed);
+ }
+ Err(ErrMode::Backtrack(e)) | Err(ErrMode::Cut(e)) => {
+ return Err(fmt_lexopt(e.to_string()));
+ }
+ Err(ErrMode::Incomplete(Needed::Size(size))) => {
+ // Without the format telling us how much space is required, we really should
+ // treat this the same as `Unknown` but are doing this to demonstrate how to
+ // handle `Size`.
+ //
+ // Even when the format has a header to tell us `Size`, we could hit incidental
+ // `Size(1)`s, so make sure we buffer more space than that to avoid reading
+ // one byte at a time
+ let head_room = size.get().max(min_buffer_growth);
+ let new_capacity = buffer.available_data() + head_room;
+ eprintln!("growing buffer to {}", new_capacity);
+ buffer.grow(new_capacity);
+ if buffer.available_space() < head_room {
+ eprintln!("buffer shift");
+ buffer.shift();
+ }
+ break;
+ }
+ Err(ErrMode::Incomplete(Needed::Unknown)) => {
+ let new_capacity = buffer_growth_factor * buffer.capacity();
+ eprintln!("growing buffer to {}", new_capacity);
+ buffer.grow(new_capacity);
+ break;
+ }
+ }
+ }
+ }
+
+ Ok(())
+}
+
+#[derive(Default)]
+struct Args {
+ input: Option<std::path::PathBuf>,
+}
+
+impl Args {
+ fn parse() -> Result<Self, lexopt::Error> {
+ use lexopt::prelude::*;
+
+ let mut res = Args::default();
+
+ let mut args = lexopt::Parser::from_env();
+ while let Some(arg) = args.next()? {
+ match arg {
+ Value(input) => {
+ res.input = Some(input.into());
+ }
+ _ => return Err(arg.unexpected()),
+ }
+ }
+ Ok(res)
+ }
+}
+
+fn to_lexopt(e: impl std::error::Error + Send + Sync + 'static) -> lexopt::Error {
+ lexopt::Error::Custom(Box::new(e))
+}
+
+fn fmt_lexopt(e: String) -> lexopt::Error {
+ lexopt::Error::Custom(e.into())
+}