From 313314e14b629ebf50389dbd2d440bda922f6ae7 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Tue, 7 May 2019 19:38:26 +0300 Subject: share literal validation logic with compiler --- crates/ra_syntax/src/string_lexing.rs | 333 ---------------------------------- 1 file changed, 333 deletions(-) delete mode 100644 crates/ra_syntax/src/string_lexing.rs (limited to 'crates/ra_syntax/src/string_lexing.rs') diff --git a/crates/ra_syntax/src/string_lexing.rs b/crates/ra_syntax/src/string_lexing.rs deleted file mode 100644 index 4c3eea3d2..000000000 --- a/crates/ra_syntax/src/string_lexing.rs +++ /dev/null @@ -1,333 +0,0 @@ -use crate::{TextRange, TextUnit}; -use self::StringComponentKind::*; - -#[derive(Debug, Eq, PartialEq, Clone)] -pub(crate) struct StringComponent { - pub(crate) range: TextRange, - pub(crate) kind: StringComponentKind, -} - -#[derive(Debug, Eq, PartialEq, Clone)] -pub(crate) enum StringComponentKind { - IgnoreNewline, - CodePoint, - AsciiEscape, - AsciiCodeEscape, - UnicodeEscape, -} - -pub(crate) fn parse_quoted_literal( - prefix: Option, - quote: char, - src: &str, -) -> StringComponentIter { - let prefix = prefix.map(|p| match p { - 'b' => b'b', - _ => panic!("invalid prefix"), - }); - let quote = match quote { - '\'' => b'\'', - '"' => b'"', - _ => panic!("invalid quote"), - }; - StringComponentIter { src, prefix, quote, pos: 0, has_closing_quote: false, suffix: None } -} - -pub(crate) struct StringComponentIter<'a> { - src: &'a str, - prefix: Option, - quote: u8, - pos: usize, - pub(crate) has_closing_quote: bool, - pub(crate) suffix: Option, -} - -impl<'a> Iterator for StringComponentIter<'a> { - type Item = StringComponent; - fn next(&mut self) -> Option { - if self.pos == 0 { - if let Some(prefix) = self.prefix { - assert!( - self.advance() == prefix as char, - "literal should start with a {:?}", - prefix as char, - ); - } - assert!( - self.advance() == self.quote as char, - "literal should start with a {:?}", - self.quote as char, - ); - } - - if let Some(component) = self.parse_component() { - return Some(component); - } - - // We get here when there are no char components left to parse - if self.peek() == Some(self.quote as char) { - self.advance(); - self.has_closing_quote = true; - if let Some(range) = self.parse_suffix() { - self.suffix = Some(range); - } - } - - assert!( - self.peek() == None, - "literal should leave no unparsed input: src = {:?}, pos = {}, length = {}", - self.src, - self.pos, - self.src.len() - ); - - None - } -} - -impl<'a> StringComponentIter<'a> { - fn peek(&self) -> Option { - if self.pos == self.src.len() { - return None; - } - - self.src[self.pos..].chars().next() - } - - fn advance(&mut self) -> char { - let next = self.peek().expect("cannot advance if end of input is reached"); - self.pos += next.len_utf8(); - next - } - - fn parse_component(&mut self) -> Option { - let next = self.peek()?; - - // Ignore string close - if next == self.quote as char { - return None; - } - - let start = self.start_range(); - self.advance(); - - if next == '\\' { - // Strings can use `\` to ignore newlines, so we first try to parse one of those - // before falling back to parsing char escapes - if self.quote == b'"' { - if let Some(component) = self.parse_ignore_newline(start) { - return Some(component); - } - } - - Some(self.parse_escape(start)) - } else { - Some(self.finish_component(start, CodePoint)) - } - } - - fn parse_ignore_newline(&mut self, start: TextUnit) -> Option { - // In string literals, when a `\` occurs immediately before the newline, the `\`, - // the newline, and all whitespace at the beginning of the next line are ignored - match self.peek() { - Some('\n') | Some('\r') => { - self.skip_whitespace(); - Some(self.finish_component(start, IgnoreNewline)) - } - _ => None, - } - } - - fn skip_whitespace(&mut self) { - while self.peek().map(|c| c.is_whitespace()) == Some(true) { - self.advance(); - } - } - - fn parse_escape(&mut self, start: TextUnit) -> StringComponent { - if self.peek().is_none() { - return self.finish_component(start, AsciiEscape); - } - - let next = self.advance(); - match next { - 'x' => self.parse_ascii_code_escape(start), - 'u' => self.parse_unicode_escape(start), - _ => self.finish_component(start, AsciiEscape), - } - } - - fn parse_unicode_escape(&mut self, start: TextUnit) -> StringComponent { - match self.peek() { - Some('{') => { - self.advance(); - - // Parse anything until we reach `}` - while let Some(next) = self.peek() { - self.advance(); - if next == '}' { - break; - } - } - - self.finish_component(start, UnicodeEscape) - } - Some(_) | None => self.finish_component(start, UnicodeEscape), - } - } - - fn parse_ascii_code_escape(&mut self, start: TextUnit) -> StringComponent { - let code_start = self.pos; - while let Some(next) = self.peek() { - if next == '\'' || (self.pos - code_start == 2) { - break; - } - - self.advance(); - } - self.finish_component(start, AsciiCodeEscape) - } - - fn parse_suffix(&mut self) -> Option { - let start = self.start_range(); - let _ = self.peek()?; - while let Some(_) = self.peek() { - self.advance(); - } - Some(self.finish_range(start)) - } - - fn start_range(&self) -> TextUnit { - TextUnit::from_usize(self.pos) - } - - fn finish_range(&self, start: TextUnit) -> TextRange { - TextRange::from_to(start, TextUnit::from_usize(self.pos)) - } - - fn finish_component(&self, start: TextUnit, kind: StringComponentKind) -> StringComponent { - let range = self.finish_range(start); - StringComponent { range, kind } - } -} - -#[cfg(test)] -mod tests { - use super::*; - - fn parse(src: &str) -> (bool, Vec) { - let component_iterator = &mut parse_quoted_literal(None, '\'', src); - let components: Vec<_> = component_iterator.collect(); - (component_iterator.has_closing_quote, components) - } - - fn unclosed_char_component(src: &str) -> StringComponent { - let (has_closing_quote, components) = parse(src); - assert!(!has_closing_quote, "char should not have closing quote"); - assert!(components.len() == 1); - components[0].clone() - } - - fn closed_char_component(src: &str) -> StringComponent { - let (has_closing_quote, components) = parse(src); - assert!(has_closing_quote, "char should have closing quote"); - assert!(components.len() == 1, "Literal: {}\nComponents: {:#?}", src, components); - components[0].clone() - } - - fn closed_char_components(src: &str) -> Vec { - let (has_closing_quote, components) = parse(src); - assert!(has_closing_quote, "char should have closing quote"); - components - } - - fn range_closed(src: &str) -> TextRange { - TextRange::from_to(1.into(), (src.len() as u32 - 1).into()) - } - - fn range_unclosed(src: &str) -> TextRange { - TextRange::from_to(1.into(), (src.len() as u32).into()) - } - - #[test] - fn test_unicode_escapes() { - let unicode_escapes = &[r"{DEAD}", "{BEEF}", "{FF}", "{}", ""]; - for escape in unicode_escapes { - let escape_sequence = format!(r"'\u{}'", escape); - let component = closed_char_component(&escape_sequence); - let expected_range = range_closed(&escape_sequence); - assert_eq!(component.kind, UnicodeEscape); - assert_eq!(component.range, expected_range); - } - } - - #[test] - fn test_unicode_escapes_unclosed() { - let unicode_escapes = &["{DEAD", "{BEEF", "{FF"]; - for escape in unicode_escapes { - let escape_sequence = format!(r"'\u{}'", escape); - let component = unclosed_char_component(&escape_sequence); - let expected_range = range_unclosed(&escape_sequence); - assert_eq!(component.kind, UnicodeEscape); - assert_eq!(component.range, expected_range); - } - } - - #[test] - fn test_empty_char() { - let (has_closing_quote, components) = parse("''"); - assert!(has_closing_quote, "char should have closing quote"); - assert!(components.len() == 0); - } - - #[test] - fn test_unclosed_char() { - let component = unclosed_char_component("'a"); - assert!(component.kind == CodePoint); - assert!(component.range == TextRange::from_to(1.into(), 2.into())); - } - - #[test] - fn test_digit_escapes() { - let literals = &[r"", r"5", r"55"]; - - for literal in literals { - let lit_text = format!(r"'\x{}'", literal); - let component = closed_char_component(&lit_text); - assert!(component.kind == AsciiCodeEscape); - assert!(component.range == range_closed(&lit_text)); - } - - // More than 2 digits starts a new codepoint - let components = closed_char_components(r"'\x555'"); - assert!(components.len() == 2); - assert!(components[1].kind == CodePoint); - } - - #[test] - fn test_ascii_escapes() { - let literals = &[ - r"\'", "\\\"", // equivalent to \" - r"\n", r"\r", r"\t", r"\\", r"\0", - ]; - - for literal in literals { - let lit_text = format!("'{}'", literal); - let component = closed_char_component(&lit_text); - assert!(component.kind == AsciiEscape); - assert!(component.range == range_closed(&lit_text)); - } - } - - #[test] - fn test_no_escapes() { - let literals = &['"', 'n', 'r', 't', '0', 'x', 'u']; - - for &literal in literals { - let lit_text = format!("'{}'", literal); - let component = closed_char_component(&lit_text); - assert!(component.kind == CodePoint); - assert!(component.range == range_closed(&lit_text)); - } - } -} -- cgit v1.2.3