Files
ruff/src/pyflakes/format.rs
2022-12-27 16:17:49 -05:00

136 lines
4.6 KiB
Rust

//! Implements helper functions for using vendored/format.rs
use std::convert::TryFrom;
use std::fmt;
use rustc_hash::FxHashSet;
use crate::vendor::format::{
FieldName, FieldType, FormatParseError, FormatPart, FormatString, FromTemplate,
};
impl fmt::Display for FormatParseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let message = match self {
FormatParseError::EmptyAttribute => "Empty attribute in format string",
FormatParseError::InvalidCharacterAfterRightBracket => {
"Only '.' or '[' may follow ']' in format field specifier"
}
FormatParseError::InvalidFormatSpecifier => "Max string recursion exceeded",
FormatParseError::MissingStartBracket => "Single '}' encountered in format string",
FormatParseError::MissingRightBracket => "Expected '}' before end of string",
FormatParseError::UnmatchedBracket => "Single '{' encountered in format string",
_ => "Unexpected error parsing format string",
};
write!(f, "{message}")
}
}
pub(crate) struct FormatSummary {
pub autos: FxHashSet<usize>,
pub indexes: FxHashSet<usize>,
pub keywords: FxHashSet<String>,
}
impl TryFrom<&str> for FormatSummary {
type Error = FormatParseError;
fn try_from(literal: &str) -> Result<Self, Self::Error> {
let format_string = FormatString::from_str(literal)?;
let mut autos = FxHashSet::default();
let mut indexes = FxHashSet::default();
let mut keywords = FxHashSet::default();
for format_part in format_string.format_parts {
let FormatPart::Field {
field_name,
format_spec,
..
} = format_part else {
continue;
};
let parsed = FieldName::parse(&field_name)?;
match parsed.field_type {
FieldType::Auto => autos.insert(autos.len()),
FieldType::Index(i) => indexes.insert(i),
FieldType::Keyword(k) => keywords.insert(k),
};
let nested = FormatString::from_str(&format_spec)?;
for nested_part in nested.format_parts {
let FormatPart::Field { field_name, .. } = nested_part else {
continue;
};
let parsed = FieldName::parse(&field_name)?;
match parsed.field_type {
FieldType::Auto => autos.insert(autos.len()),
FieldType::Index(i) => indexes.insert(i),
FieldType::Keyword(k) => keywords.insert(k),
};
}
}
Ok(FormatSummary {
autos,
indexes,
keywords,
})
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::vendor::format::FromTemplate;
#[test]
fn test_format_summary() {
let literal = "foo{foo}a{}b{2}c{2}d{1}{}{}e{bar}{foo}f{spam}";
let expected_autos = [0usize, 1usize, 2usize].into_iter().collect();
let expected_indexes = [1usize, 2usize].into_iter().collect();
let expected_keywords = ["foo", "bar", "spam"]
.into_iter()
.map(String::from)
.collect();
let format_summary = FormatSummary::try_from(literal).unwrap();
assert_eq!(format_summary.autos, expected_autos);
assert_eq!(format_summary.indexes, expected_indexes);
assert_eq!(format_summary.keywords, expected_keywords);
}
#[test]
fn test_format_summary_nested() {
let literal = "foo{foo}a{:{}{}}b{2:{3}{4}}c{2}d{1}{}e{bar:{spam}{eggs}}";
let expected_autos = [0usize, 1usize, 2usize, 3usize].into_iter().collect();
let expected_indexes = [1usize, 2usize, 3usize, 4usize].into_iter().collect();
let expected_keywords = ["foo", "bar", "spam", "eggs"]
.into_iter()
.map(String::from)
.collect();
let format_summary = FormatSummary::try_from(literal).unwrap();
assert_eq!(format_summary.autos, expected_autos);
assert_eq!(format_summary.indexes, expected_indexes);
assert_eq!(format_summary.keywords, expected_keywords);
}
#[test]
fn test_format_summary_invalid() {
assert!(FormatSummary::try_from("{").is_err());
let literal = "{foo}a{}b{bar..}";
assert!(FormatString::from_str(literal).is_ok());
assert!(FormatSummary::try_from(literal).is_err());
let literal_nested = "{foo}a{}b{bar:{spam..}}";
assert!(FormatString::from_str(literal_nested).is_ok());
assert!(FormatSummary::try_from(literal_nested).is_err());
}
}