Remove parser dependency from ruff-python-ast (#6096)

crates/ruff_source_file/src/lib.rs

@@ -0,0 +1,250 @@
+use std::cmp::Ordering;
+use std::fmt::{Debug, Formatter};
+use std::sync::Arc;
+
+use ruff_text_size::{TextRange, TextSize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+pub mod line_index;
+mod locator;
+pub mod newlines;
+
+pub use crate::line_index::{LineIndex, OneIndexed};
+pub use locator::Locator;
+pub use newlines::{
+    find_newline, Line, LineEnding, NewlineWithTrailingNewline, UniversalNewlineIterator,
+    UniversalNewlines,
+};
+
+/// Gives access to the source code of a file and allows mapping between [`TextSize`] and [`SourceLocation`].
+#[derive(Debug)]
+pub struct SourceCode<'src, 'index> {
+    text: &'src str,
+    index: &'index LineIndex,
+}
+
+impl<'src, 'index> SourceCode<'src, 'index> {
+    pub fn new(content: &'src str, index: &'index LineIndex) -> Self {
+        Self {
+            text: content,
+            index,
+        }
+    }
+
+    /// Computes the one indexed row and column numbers for `offset`.
+    #[inline]
+    pub fn source_location(&self, offset: TextSize) -> SourceLocation {
+        self.index.source_location(offset, self.text)
+    }
+
+    #[inline]
+    pub fn line_index(&self, offset: TextSize) -> OneIndexed {
+        self.index.line_index(offset)
+    }
+
+    /// Take the source code up to the given [`TextSize`].
+    #[inline]
+    pub fn up_to(&self, offset: TextSize) -> &'src str {
+        &self.text[TextRange::up_to(offset)]
+    }
+
+    /// Take the source code after the given [`TextSize`].
+    #[inline]
+    pub fn after(&self, offset: TextSize) -> &'src str {
+        &self.text[usize::from(offset)..]
+    }
+
+    /// Take the source code between the given [`TextRange`].
+    pub fn slice(&self, range: TextRange) -> &'src str {
+        &self.text[range]
+    }
+
+    pub fn line_start(&self, line: OneIndexed) -> TextSize {
+        self.index.line_start(line, self.text)
+    }
+
+    pub fn line_end(&self, line: OneIndexed) -> TextSize {
+        self.index.line_end(line, self.text)
+    }
+
+    pub fn line_range(&self, line: OneIndexed) -> TextRange {
+        self.index.line_range(line, self.text)
+    }
+
+    /// Returns the source text of the line with the given index
+    #[inline]
+    pub fn line_text(&self, index: OneIndexed) -> &'src str {
+        let range = self.index.line_range(index, self.text);
+        &self.text[range]
+    }
+
+    /// Returns the source text
+    pub fn text(&self) -> &'src str {
+        self.text
+    }
+
+    /// Returns the number of lines
+    #[inline]
+    pub fn line_count(&self) -> usize {
+        self.index.line_count()
+    }
+}
+
+impl PartialEq<Self> for SourceCode<'_, '_> {
+    fn eq(&self, other: &Self) -> bool {
+        self.text == other.text
+    }
+}
+
+impl Eq for SourceCode<'_, '_> {}
+
+/// A Builder for constructing a [`SourceFile`]
+pub struct SourceFileBuilder {
+    name: Box<str>,
+    code: Box<str>,
+    index: Option<LineIndex>,
+}
+
+impl SourceFileBuilder {
+    /// Creates a new builder for a file named `name`.
+    pub fn new<Name: Into<Box<str>>, Code: Into<Box<str>>>(name: Name, code: Code) -> Self {
+        Self {
+            name: name.into(),
+            code: code.into(),
+            index: None,
+        }
+    }
+
+    #[must_use]
+    pub fn line_index(mut self, index: LineIndex) -> Self {
+        self.index = Some(index);
+        self
+    }
+
+    pub fn set_line_index(&mut self, index: LineIndex) {
+        self.index = Some(index);
+    }
+
+    /// Consumes `self` and returns the [`SourceFile`].
+    pub fn finish(self) -> SourceFile {
+        let index = if let Some(index) = self.index {
+            once_cell::sync::OnceCell::with_value(index)
+        } else {
+            once_cell::sync::OnceCell::new()
+        };
+
+        SourceFile {
+            inner: Arc::new(SourceFileInner {
+                name: self.name,
+                code: self.code,
+                line_index: index,
+            }),
+        }
+    }
+}
+
+/// A source file that is identified by its name. Optionally stores the source code and [`LineIndex`].
+///
+/// Cloning a [`SourceFile`] is cheap, because it only requires bumping a reference count.
+#[derive(Clone, Eq, PartialEq)]
+pub struct SourceFile {
+    inner: Arc<SourceFileInner>,
+}
+
+impl Debug for SourceFile {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("SourceFile")
+            .field("name", &self.name())
+            .field("code", &self.source_text())
+            .finish()
+    }
+}
+
+impl SourceFile {
+    /// Returns the name of the source file (filename).
+    #[inline]
+    pub fn name(&self) -> &str {
+        &self.inner.name
+    }
+
+    #[inline]
+    pub fn slice(&self, range: TextRange) -> &str {
+        &self.source_text()[range]
+    }
+
+    pub fn to_source_code(&self) -> SourceCode {
+        SourceCode {
+            text: self.source_text(),
+            index: self.index(),
+        }
+    }
+
+    fn index(&self) -> &LineIndex {
+        self.inner
+            .line_index
+            .get_or_init(|| LineIndex::from_source_text(self.source_text()))
+    }
+
+    /// Returns the source code.
+    #[inline]
+    pub fn source_text(&self) -> &str {
+        &self.inner.code
+    }
+}
+
+impl PartialOrd for SourceFile {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for SourceFile {
+    fn cmp(&self, other: &Self) -> Ordering {
+        // Short circuit if these are the same source files
+        if Arc::ptr_eq(&self.inner, &other.inner) {
+            Ordering::Equal
+        } else {
+            self.inner.name.cmp(&other.inner.name)
+        }
+    }
+}
+
+struct SourceFileInner {
+    name: Box<str>,
+    code: Box<str>,
+    line_index: once_cell::sync::OnceCell<LineIndex>,
+}
+
+impl PartialEq for SourceFileInner {
+    fn eq(&self, other: &Self) -> bool {
+        self.name == other.name && self.code == other.code
+    }
+}
+
+impl Eq for SourceFileInner {}
+
+#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct SourceLocation {
+    pub row: OneIndexed,
+    pub column: OneIndexed,
+}
+
+impl Default for SourceLocation {
+    fn default() -> Self {
+        Self {
+            row: OneIndexed::MIN,
+            column: OneIndexed::MIN,
+        }
+    }
+}
+
+impl Debug for SourceLocation {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("SourceLocation")
+            .field("row", &self.row.get())
+            .field("column", &self.column.get())
+            .finish()
+    }
+}