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Diffstat (limited to 'third_party/rust/clap_lex/src/lib.rs')
| -rw-r--r-- | third_party/rust/clap_lex/src/lib.rs | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/third_party/rust/clap_lex/src/lib.rs b/third_party/rust/clap_lex/src/lib.rs new file mode 100644 index 0000000000..f205c3de01 --- /dev/null +++ b/third_party/rust/clap_lex/src/lib.rs @@ -0,0 +1,484 @@ +//! Minimal, flexible command-line parser +//! +//! As opposed to a declarative parser, this processes arguments as a stream of tokens. As lexing +//! a command-line is not context-free, we rely on the caller to decide how to interpret the +//! arguments. +//! +//! # Examples +//! +//! ```rust +//! # use std::path::PathBuf; +//! # type BoxedError = Box<dyn std::error::Error + Send + Sync>; +//! #[derive(Debug)] +//! struct Args { +//! paths: Vec<PathBuf>, +//! color: Color, +//! verbosity: usize, +//! } +//! +//! #[derive(Debug)] +//! enum Color { +//! Always, +//! Auto, +//! Never, +//! } +//! +//! impl Color { +//! fn parse(s: Option<&clap_lex::RawOsStr>) -> Result<Self, BoxedError> { +//! let s = s.map(|s| s.to_str().ok_or(s)); +//! match s { +//! Some(Ok("always")) | Some(Ok("")) | None => { +//! Ok(Color::Always) +//! } +//! Some(Ok("auto")) => { +//! Ok(Color::Auto) +//! } +//! Some(Ok("never")) => { +//! Ok(Color::Never) +//! } +//! Some(invalid) => { +//! Err(format!("Invalid value for `--color`, {:?}", invalid).into()) +//! } +//! } +//! } +//! } +//! +//! fn parse_args( +//! raw: impl IntoIterator<Item=impl Into<std::ffi::OsString>> +//! ) -> Result<Args, BoxedError> { +//! let mut args = Args { +//! paths: Vec::new(), +//! color: Color::Auto, +//! verbosity: 0, +//! }; +//! +//! let raw = clap_lex::RawArgs::new(raw); +//! let mut cursor = raw.cursor(); +//! raw.next(&mut cursor); // Skip the bin +//! while let Some(arg) = raw.next(&mut cursor) { +//! if arg.is_escape() { +//! args.paths.extend(raw.remaining(&mut cursor).map(PathBuf::from)); +//! } else if arg.is_stdio() { +//! args.paths.push(PathBuf::from("-")); +//! } else if let Some((long, value)) = arg.to_long() { +//! match long { +//! Ok("verbose") => { +//! if let Some(value) = value { +//! return Err(format!("`--verbose` does not take a value, got `{:?}`", value).into()); +//! } +//! args.verbosity += 1; +//! } +//! Ok("color") => { +//! args.color = Color::parse(value)?; +//! } +//! _ => { +//! return Err( +//! format!("Unexpected flag: --{}", arg.display()).into() +//! ); +//! } +//! } +//! } else if let Some(mut shorts) = arg.to_short() { +//! while let Some(short) = shorts.next_flag() { +//! match short { +//! Ok('v') => { +//! args.verbosity += 1; +//! } +//! Ok('c') => { +//! let value = shorts.next_value_os(); +//! args.color = Color::parse(value)?; +//! } +//! Ok(c) => { +//! return Err(format!("Unexpected flag: -{}", c).into()); +//! } +//! Err(e) => { +//! return Err(format!("Unexpected flag: -{}", e.to_str_lossy()).into()); +//! } +//! } +//! } +//! } else { +//! args.paths.push(PathBuf::from(arg.to_value_os().to_os_str().into_owned())); +//! } +//! } +//! +//! Ok(args) +//! } +//! +//! let args = parse_args(["bin", "--hello", "world"]); +//! println!("{:?}", args); +//! ``` + +use std::ffi::OsStr; +use std::ffi::OsString; + +pub use std::io::SeekFrom; + +pub use os_str_bytes::RawOsStr; +pub use os_str_bytes::RawOsString; + +/// Command-line arguments +#[derive(Default, Clone, Debug, PartialEq, Eq)] +pub struct RawArgs { + items: Vec<OsString>, +} + +impl RawArgs { + //// Create an argument list to parse + /// + /// **NOTE:** The argument returned will be the current binary. + /// + /// # Example + /// + /// ```rust,no_run + /// # use std::path::PathBuf; + /// let raw = clap_lex::RawArgs::from_args(); + /// let mut cursor = raw.cursor(); + /// let _bin = raw.next_os(&mut cursor); + /// + /// let mut paths = raw.remaining(&mut cursor).map(PathBuf::from).collect::<Vec<_>>(); + /// println!("{:?}", paths); + /// ``` + pub fn from_args() -> Self { + Self::new(std::env::args_os()) + } + + //// Create an argument list to parse + /// + /// # Example + /// + /// ```rust,no_run + /// # use std::path::PathBuf; + /// let raw = clap_lex::RawArgs::new(["bin", "foo.txt"]); + /// let mut cursor = raw.cursor(); + /// let _bin = raw.next_os(&mut cursor); + /// + /// let mut paths = raw.remaining(&mut cursor).map(PathBuf::from).collect::<Vec<_>>(); + /// println!("{:?}", paths); + /// ``` + pub fn new(iter: impl IntoIterator<Item = impl Into<std::ffi::OsString>>) -> Self { + let iter = iter.into_iter(); + Self::from(iter) + } + + /// Create a cursor for walking the arguments + /// + /// # Example + /// + /// ```rust,no_run + /// # use std::path::PathBuf; + /// let raw = clap_lex::RawArgs::new(["bin", "foo.txt"]); + /// let mut cursor = raw.cursor(); + /// let _bin = raw.next_os(&mut cursor); + /// + /// let mut paths = raw.remaining(&mut cursor).map(PathBuf::from).collect::<Vec<_>>(); + /// println!("{:?}", paths); + /// ``` + pub fn cursor(&self) -> ArgCursor { + ArgCursor::new() + } + + /// Advance the cursor, returning the next [`ParsedArg`] + pub fn next(&self, cursor: &mut ArgCursor) -> Option<ParsedArg<'_>> { + self.next_os(cursor).map(ParsedArg::new) + } + + /// Advance the cursor, returning a raw argument value. + pub fn next_os(&self, cursor: &mut ArgCursor) -> Option<&OsStr> { + let next = self.items.get(cursor.cursor).map(|s| s.as_os_str()); + cursor.cursor = cursor.cursor.saturating_add(1); + next + } + + /// Return the next [`ParsedArg`] + pub fn peek(&self, cursor: &ArgCursor) -> Option<ParsedArg<'_>> { + self.peek_os(cursor).map(ParsedArg::new) + } + + /// Return a raw argument value. + pub fn peek_os(&self, cursor: &ArgCursor) -> Option<&OsStr> { + self.items.get(cursor.cursor).map(|s| s.as_os_str()) + } + + /// Return all remaining raw arguments, advancing the cursor to the end + /// + /// # Example + /// + /// ```rust,no_run + /// # use std::path::PathBuf; + /// let raw = clap_lex::RawArgs::new(["bin", "foo.txt"]); + /// let mut cursor = raw.cursor(); + /// let _bin = raw.next_os(&mut cursor); + /// + /// let mut paths = raw.remaining(&mut cursor).map(PathBuf::from).collect::<Vec<_>>(); + /// println!("{:?}", paths); + /// ``` + pub fn remaining(&self, cursor: &mut ArgCursor) -> impl Iterator<Item = &OsStr> { + let remaining = self.items[cursor.cursor..].iter().map(|s| s.as_os_str()); + cursor.cursor = self.items.len(); + remaining + } + + /// Adjust the cursor's position + pub fn seek(&self, cursor: &mut ArgCursor, pos: SeekFrom) { + let pos = match pos { + SeekFrom::Start(pos) => pos, + SeekFrom::End(pos) => (self.items.len() as i64).saturating_add(pos).max(0) as u64, + SeekFrom::Current(pos) => (cursor.cursor as i64).saturating_add(pos).max(0) as u64, + }; + let pos = (pos as usize).min(self.items.len()); + cursor.cursor = pos; + } + + /// Inject arguments before the [`RawArgs::next`] + pub fn insert(&mut self, cursor: &ArgCursor, insert_items: &[&str]) { + self.items.splice( + cursor.cursor..cursor.cursor, + insert_items.iter().map(OsString::from), + ); + } + + /// Any remaining args? + pub fn is_end(&self, cursor: &ArgCursor) -> bool { + self.peek_os(cursor).is_none() + } +} + +impl<I, T> From<I> for RawArgs +where + I: Iterator<Item = T>, + T: Into<OsString>, +{ + fn from(val: I) -> Self { + Self { + items: val.map(|x| x.into()).collect(), + } + } +} + +/// Position within [`RawArgs`] +#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)] +pub struct ArgCursor { + cursor: usize, +} + +impl ArgCursor { + fn new() -> Self { + Self { cursor: 0 } + } +} + +/// Command-line Argument +#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct ParsedArg<'s> { + inner: std::borrow::Cow<'s, RawOsStr>, + utf8: Option<&'s str>, +} + +impl<'s> ParsedArg<'s> { + fn new(inner: &'s OsStr) -> Self { + let utf8 = inner.to_str(); + let inner = RawOsStr::new(inner); + Self { inner, utf8 } + } + + /// Argument is length of 0 + pub fn is_empty(&self) -> bool { + self.inner.as_ref().is_empty() + } + + /// Does the argument look like a stdio argument (`-`) + pub fn is_stdio(&self) -> bool { + self.inner.as_ref() == "-" + } + + /// Does the argument look like an argument escape (`--`) + pub fn is_escape(&self) -> bool { + self.inner.as_ref() == "--" + } + + /// Does the argument look like a number + pub fn is_number(&self) -> bool { + self.to_value() + .map(|s| s.parse::<f64>().is_ok()) + .unwrap_or_default() + } + + /// Treat as a long-flag + pub fn to_long(&self) -> Option<(Result<&str, &RawOsStr>, Option<&RawOsStr>)> { + if let Some(raw) = self.utf8 { + let remainder = raw.strip_prefix("--")?; + if remainder.is_empty() { + debug_assert!(self.is_escape()); + return None; + } + + let (flag, value) = if let Some((p0, p1)) = remainder.split_once('=') { + (p0, Some(p1)) + } else { + (remainder, None) + }; + let flag = Ok(flag); + let value = value.map(RawOsStr::from_str); + Some((flag, value)) + } else { + let raw = self.inner.as_ref(); + let remainder = raw.strip_prefix("--")?; + if remainder.is_empty() { + debug_assert!(self.is_escape()); + return None; + } + + let (flag, value) = if let Some((p0, p1)) = remainder.split_once('=') { + (p0, Some(p1)) + } else { + (remainder, None) + }; + let flag = flag.to_str().ok_or(flag); + Some((flag, value)) + } + } + + /// Can treat as a long-flag + pub fn is_long(&self) -> bool { + self.inner.as_ref().starts_with("--") && !self.is_escape() + } + + /// Treat as a short-flag + pub fn to_short(&self) -> Option<ShortFlags<'_>> { + if let Some(remainder_os) = self.inner.as_ref().strip_prefix('-') { + if remainder_os.starts_with('-') { + None + } else if remainder_os.is_empty() { + debug_assert!(self.is_stdio()); + None + } else { + let remainder = self.utf8.map(|s| &s[1..]); + Some(ShortFlags::new(remainder_os, remainder)) + } + } else { + None + } + } + + /// Can treat as a short-flag + pub fn is_short(&self) -> bool { + self.inner.as_ref().starts_with('-') + && !self.is_stdio() + && !self.inner.as_ref().starts_with("--") + } + + /// Treat as a value + /// + /// **NOTE:** May return a flag or an escape. + pub fn to_value_os(&self) -> &RawOsStr { + self.inner.as_ref() + } + + /// Treat as a value + /// + /// **NOTE:** May return a flag or an escape. + pub fn to_value(&self) -> Result<&str, &RawOsStr> { + self.utf8.ok_or_else(|| self.inner.as_ref()) + } + + /// Safely print an argument that may contain non-UTF8 content + /// + /// This may perform lossy conversion, depending on the platform. If you would like an implementation which escapes the path please use Debug instead. + pub fn display(&self) -> impl std::fmt::Display + '_ { + self.inner.to_str_lossy() + } +} + +/// Walk through short flags within a [`ParsedArg`] +#[derive(Clone, Debug)] +pub struct ShortFlags<'s> { + inner: &'s RawOsStr, + utf8_prefix: std::str::CharIndices<'s>, + invalid_suffix: Option<&'s RawOsStr>, +} + +impl<'s> ShortFlags<'s> { + fn new(inner: &'s RawOsStr, utf8: Option<&'s str>) -> Self { + let (utf8_prefix, invalid_suffix) = if let Some(utf8) = utf8 { + (utf8, None) + } else { + split_nonutf8_once(inner) + }; + let utf8_prefix = utf8_prefix.char_indices(); + Self { + inner, + utf8_prefix, + invalid_suffix, + } + } + + /// Move the iterator forward by `n` short flags + pub fn advance_by(&mut self, n: usize) -> Result<(), usize> { + for i in 0..n { + self.next().ok_or(i)?.map_err(|_| i)?; + } + Ok(()) + } + + /// No short flags left + pub fn is_empty(&self) -> bool { + self.invalid_suffix.is_none() && self.utf8_prefix.as_str().is_empty() + } + + /// Does the short flag look like a number + /// + /// Ideally call this before doing any iterator + pub fn is_number(&self) -> bool { + self.invalid_suffix.is_none() && self.utf8_prefix.as_str().parse::<f64>().is_ok() + } + + /// Advance the iterator, returning the next short flag on success + /// + /// On error, returns the invalid-UTF8 value + pub fn next_flag(&mut self) -> Option<Result<char, &'s RawOsStr>> { + if let Some((_, flag)) = self.utf8_prefix.next() { + return Some(Ok(flag)); + } + + if let Some(suffix) = self.invalid_suffix { + self.invalid_suffix = None; + return Some(Err(suffix)); + } + + None + } + + /// Advance the iterator, returning everything left as a value + pub fn next_value_os(&mut self) -> Option<&'s RawOsStr> { + if let Some((index, _)) = self.utf8_prefix.next() { + self.utf8_prefix = "".char_indices(); + self.invalid_suffix = None; + return Some(&self.inner[index..]); + } + + if let Some(suffix) = self.invalid_suffix { + self.invalid_suffix = None; + return Some(suffix); + } + + None + } +} + +impl<'s> Iterator for ShortFlags<'s> { + type Item = Result<char, &'s RawOsStr>; + + fn next(&mut self) -> Option<Self::Item> { + self.next_flag() + } +} + +fn split_nonutf8_once(b: &RawOsStr) -> (&str, Option<&RawOsStr>) { + match std::str::from_utf8(b.as_raw_bytes()) { + Ok(s) => (s, None), + Err(err) => { + let (valid, after_valid) = b.split_at(err.valid_up_to()); + let valid = std::str::from_utf8(valid.as_raw_bytes()).unwrap(); + (valid, Some(after_valid)) + } + } +} |