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#![cfg(feature = "unstable")]
#![cfg_attr(docsrs, feature(doc_cfg))]
#![cfg_attr(docsrs, doc(cfg(unstable)))]
#![doc(html_logo_url = "https://knurling.ferrous-systems.com/knurling_logo_light_text.svg")]
mod display_hint;
#[cfg(test)]
mod tests;
mod types;
use std::{borrow::Cow, ops::Range};
pub use crate::{
display_hint::{DisplayHint, TimePrecision},
types::Type,
};
#[derive(thiserror::Error, Debug, PartialEq, Eq, Clone)]
pub enum Error {
#[error("invalid type specifier `{0:?}`")]
InvalidTypeSpecifier(String),
#[error("unable to parse given integer")]
InvalidInteger(#[from] std::num::ParseIntError),
#[error("invalid array specifier (missing length)")]
InvalidArraySpecifierMissingLength,
#[error("invalid array specifier (missing `]`")]
InvalidArraySpecifierMissingBracket,
#[error("trailing data after bitfield range")]
TrailingDataAfterBitfieldRange,
#[error("malformed format string (missing display hint after ':')")]
MalformedFormatString,
#[error("unknown display hint: {0:?}")]
UnknownDisplayHint(String),
#[error("unexpected content `{0:?}` in format string")]
UnexpectedContentInFormatString(String),
#[error("unmatched `{{` in format string")]
UnmatchedOpenBracket,
#[error("unmatched `}}` in format string")]
UnmatchedCloseBracket,
#[error("conflicting types for argument {0}: used as {1:?} and {2:?}")]
ConflictingTypes(usize, Type, Type),
#[error("argument {0} is not used in this format string")]
UnusedArgument(usize),
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Parameter {
pub index: usize,
pub ty: Type,
pub hint: Option<DisplayHint>,
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum Fragment<'f> {
Literal(Cow<'f, str>),
Parameter(Parameter),
}
#[derive(Debug, PartialEq)]
struct Param {
index: Option<usize>,
ty: Type,
hint: Option<DisplayHint>,
}
#[derive(Clone, Copy, Debug, Eq, PartialEq, PartialOrd)]
pub enum Level {
Trace,
Debug,
Info,
Warn,
Error,
}
impl Level {
pub fn as_str(self) -> &'static str {
match self {
Level::Trace => "trace",
Level::Debug => "debug",
Level::Info => "info",
Level::Warn => "warn",
Level::Error => "error",
}
}
}
fn parse_range(mut s: &str) -> Option<(Range<u8>, usize )> {
let start_digits = s
.as_bytes()
.iter()
.take_while(|b| (**b as char).is_ascii_digit())
.count();
let start = s[..start_digits].parse().ok()?;
if &s[start_digits..start_digits + 2] != ".." {
return None;
}
s = &s[start_digits + 2..];
let end_digits = s
.as_bytes()
.iter()
.take_while(|b| (**b as char).is_ascii_digit())
.count();
let end = s[..end_digits].parse().ok()?;
if end <= start || start >= 128 || end > 128 {
return None;
}
Some((start..end, start_digits + end_digits + 2))
}
fn parse_array(mut s: &str) -> Result<usize, Error> {
let len_pos = s
.find(|c: char| c != ' ')
.ok_or(Error::InvalidArraySpecifierMissingLength)?;
s = &s[len_pos..];
let after_len = s
.find(|c: char| !c.is_ascii_digit())
.ok_or(Error::InvalidArraySpecifierMissingBracket)?;
let len = s[..after_len].parse::<usize>()?;
s = &s[after_len..];
if s != "]" {
return Err(Error::InvalidArraySpecifierMissingBracket);
}
Ok(len)
}
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum ParserMode {
Strict,
ForwardsCompatible,
}
fn parse_param(mut input: &str, mode: ParserMode) -> Result<Param, Error> {
const TYPE_PREFIX: &str = "=";
const HINT_PREFIX: &str = ":";
let mut index = None;
let index_end = input
.find(|c: char| !c.is_ascii_digit())
.unwrap_or(input.len());
if index_end != 0 {
index = Some(input[..index_end].parse::<usize>()?);
}
let mut ty = Type::default(); input = &input[index_end..];
if input.starts_with(TYPE_PREFIX) {
input = &input[TYPE_PREFIX.len()..];
let type_end = input.find(HINT_PREFIX).unwrap_or(input.len());
let type_fragment = &input[..type_end];
const FORMAT_ARRAY_START: &str = "[?;";
const U8_ARRAY_START: &str = "[u8;";
ty = if let Ok(ty) = type_fragment.parse() {
Ok(ty)
} else if let Some(s) = type_fragment.strip_prefix(U8_ARRAY_START) {
Ok(Type::U8Array(parse_array(s)?))
} else if let Some(s) = type_fragment.strip_prefix(FORMAT_ARRAY_START) {
Ok(Type::FormatArray(parse_array(s)?))
} else if let Some((range, used)) = parse_range(type_fragment) {
match used != type_fragment.len() {
true => Err(Error::TrailingDataAfterBitfieldRange),
false => Ok(Type::BitField(range)),
}
} else {
Err(Error::InvalidTypeSpecifier(input.to_owned()))
}?;
input = &input[type_end..];
}
let mut hint = None;
if input.starts_with(HINT_PREFIX) {
input = &input[HINT_PREFIX.len()..];
if input.is_empty() {
return Err(Error::MalformedFormatString);
}
hint = match (DisplayHint::parse(input), mode) {
(Some(a), _) => Some(a),
(None, ParserMode::Strict) => return Err(Error::UnknownDisplayHint(input.to_owned())),
(None, ParserMode::ForwardsCompatible) => Some(DisplayHint::Unknown(input.to_owned())),
};
} else if !input.is_empty() {
return Err(Error::UnexpectedContentInFormatString(input.to_owned()));
}
Ok(Param { index, ty, hint })
}
fn push_literal<'f>(frag: &mut Vec<Fragment<'f>>, unescaped_literal: &'f str) -> Result<(), Error> {
let mut last_open = false;
let mut last_close = false;
for c in unescaped_literal.chars() {
match c {
'{' => last_open = !last_open,
'}' => last_close = !last_close,
_ if last_open => return Err(Error::UnmatchedOpenBracket),
_ if last_close => return Err(Error::UnmatchedCloseBracket),
_ => {}
}
}
if last_open {
return Err(Error::UnmatchedOpenBracket);
} else if last_close {
return Err(Error::UnmatchedCloseBracket);
}
let literal = unescaped_literal.replace("{{", "{").replace("}}", "}");
frag.push(Fragment::Literal(literal.into()));
Ok(())
}
pub fn get_max_bitfield_range<'a, I>(params: I) -> Option<(u8, u8)>
where
I: Iterator<Item = &'a Parameter> + Clone,
{
let largest_bit_index = params
.clone()
.map(|param| match ¶m.ty {
Type::BitField(range) => range.end,
_ => unreachable!(),
})
.max();
let smallest_bit_index = params
.map(|param| match ¶m.ty {
Type::BitField(range) => range.start,
_ => unreachable!(),
})
.min();
match (smallest_bit_index, largest_bit_index) {
(Some(smallest), Some(largest)) => Some((smallest, largest)),
(None, None) => None,
_ => unreachable!(),
}
}
pub fn parse(format_string: &str, mode: ParserMode) -> Result<Vec<Fragment<'_>>, Error> {
let mut fragments = Vec::new();
let mut end_pos = 0;
let mut next_arg_index = 0;
let mut chars = format_string.char_indices();
while let Some((brace_pos, ch)) = chars.next() {
if ch != '{' {
continue;
}
if chars.as_str().starts_with('{') {
chars.next(); continue;
}
if brace_pos > end_pos {
let unescaped_literal = &format_string[end_pos..brace_pos];
push_literal(&mut fragments, unescaped_literal)?;
}
let len = chars
.as_str()
.find('}')
.ok_or(Error::UnmatchedOpenBracket)?;
end_pos = brace_pos + 1 + len + 1;
let param_str = &format_string[brace_pos + 1..][..len];
let param = parse_param(param_str, mode)?;
fragments.push(Fragment::Parameter(Parameter {
index: param.index.unwrap_or_else(|| {
let idx = next_arg_index;
next_arg_index += 1;
idx
}),
ty: param.ty,
hint: param.hint,
}));
}
if end_pos != format_string.len() {
push_literal(&mut fragments, &format_string[end_pos..])?;
}
let mut args = Vec::new();
for frag in &fragments {
if let Fragment::Parameter(Parameter { index, ty, .. }) = frag {
if args.len() <= *index {
args.resize(*index + 1, None);
}
match &args[*index] {
None => args[*index] = Some(ty.clone()),
Some(other_ty) => match (other_ty, ty) {
(Type::BitField(_), Type::BitField(_)) => {} (a, b) if a != b => {
return Err(Error::ConflictingTypes(*index, a.clone(), b.clone()))
}
_ => {}
},
}
}
}
for (index, arg) in args.iter().enumerate() {
if arg.is_none() {
return Err(Error::UnusedArgument(index));
}
}
Ok(fragments)
}