Move SourceCodeLocator to its own module (#522)

benches/source_code_locator.rs

@@ -2,8 +2,8 @@ use std::path::Path;
 
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 
-use ruff::ast::operations::{compute_offsets, compute_offsets_v0};
 use ruff::fs;
+use ruff::source_code_locator::compute_offsets;
 
 fn criterion_benchmark(c: &mut Criterion) {
     let contents = fs::read_file(Path::new("resources/test/fixtures/D.py")).unwrap();

src/ast/operations.rs

@@ -1,7 +1,6 @@
-use once_cell::unsync::OnceCell;
-use rustpython_parser::ast::{Constant, Expr, ExprKind, Location, Stmt, StmtKind};
+use rustpython_parser::ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
 
-use crate::ast::types::{BindingKind, Range, Scope};
+use crate::ast::types::{BindingKind, Scope};
 
 /// Extract the names bound to a given __all__ assignment.
 pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
@@ -118,112 +117,3 @@ pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
     }
     false
 }
-
-/// Struct used to efficiently slice source code at (row, column) Locations.
-pub struct SourceCodeLocator<'a> {
-    contents: &'a str,
-    offsets: OnceCell<Vec<Vec<usize>>>,
-}
-
-pub fn compute_offsets(contents: &str) -> Vec<Vec<usize>> {
-    let mut offsets = vec![vec![]];
-    let mut line_index = 0;
-    let mut char_index = 0;
-    let mut newline = false;
-    for (i, char) in contents.char_indices() {
-        offsets[line_index].push(i);
-
-        newline = char == '\n';
-        if newline {
-            line_index += 1;
-            offsets.push(vec![]);
-            char_index = i + char.len_utf8();
-        }
-    }
-    // If we end in a newline, add an extra character to indicate the start of that line.
-    if newline {
-        offsets[line_index].push(char_index);
-    }
-    offsets
-}
-
-impl<'a> SourceCodeLocator<'a> {
-    pub fn new(contents: &'a str) -> Self {
-        SourceCodeLocator {
-            contents,
-            offsets: OnceCell::new(),
-        }
-    }
-
-    fn get_or_init_offsets(&self) -> &Vec<Vec<usize>> {
-        self.offsets.get_or_init(|| compute_offsets(self.contents))
-    }
-
-    pub fn slice_source_code_at(&self, location: &Location) -> &'a str {
-        let offsets = self.get_or_init_offsets();
-        let offset = offsets[location.row() - 1][location.column() - 1];
-        &self.contents[offset..]
-    }
-
-    pub fn slice_source_code_range(&self, range: &Range) -> &'a str {
-        let offsets = self.get_or_init_offsets();
-        let start = offsets[range.location.row() - 1][range.location.column() - 1];
-        let end = offsets[range.end_location.row() - 1][range.end_location.column() - 1];
-        &self.contents[start..end]
-    }
-
-    pub fn partition_source_code_at(
-        &self,
-        outer: &Range,
-        inner: &Range,
-    ) -> (&'a str, &'a str, &'a str) {
-        let offsets = self.get_or_init_offsets();
-        let outer_start = offsets[outer.location.row() - 1][outer.location.column() - 1];
-        let outer_end = offsets[outer.end_location.row() - 1][outer.end_location.column() - 1];
-        let inner_start = offsets[inner.location.row() - 1][inner.location.column() - 1];
-        let inner_end = offsets[inner.end_location.row() - 1][inner.end_location.column() - 1];
-        (
-            &self.contents[outer_start..inner_start],
-            &self.contents[inner_start..inner_end],
-            &self.contents[inner_end..outer_end],
-        )
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::SourceCodeLocator;
-
-    #[test]
-    fn source_code_locator_init() {
-        let content = "x = 1";
-        let locator = SourceCodeLocator::new(content);
-        let offsets = locator.get_or_init_offsets();
-        assert_eq!(offsets.len(), 1);
-        assert_eq!(offsets[0], [0, 1, 2, 3, 4]);
-
-        let content = "x = 1\n";
-        let locator = SourceCodeLocator::new(content);
-        let offsets = locator.get_or_init_offsets();
-        assert_eq!(offsets.len(), 2);
-        assert_eq!(offsets[0], [0, 1, 2, 3, 4, 5]);
-        assert_eq!(offsets[1], [6]);
-
-        let content = "x = 1\ny = 2\nz = x + y\n";
-        let locator = SourceCodeLocator::new(content);
-        let offsets = locator.get_or_init_offsets();
-        assert_eq!(offsets.len(), 4);
-        assert_eq!(offsets[0], [0, 1, 2, 3, 4, 5]);
-        assert_eq!(offsets[1], [6, 7, 8, 9, 10, 11]);
-        assert_eq!(offsets[2], [12, 13, 14, 15, 16, 17, 18, 19, 20, 21]);
-        assert_eq!(offsets[3], [22]);
-
-        let content = "# \u{4e9c}\nclass Foo:\n    \"\"\".\"\"\"";
-        let locator = SourceCodeLocator::new(content);
-        let offsets = locator.get_or_init_offsets();
-        assert_eq!(offsets.len(), 3);
-        assert_eq!(offsets[0], [0, 1, 2, 5]);
-        assert_eq!(offsets[1], [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
-        assert_eq!(offsets[2], [17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27]);
-    }
-}

src/check_ast.rs

@@ -12,7 +12,7 @@ use rustpython_parser::ast::{
 use rustpython_parser::parser;
 
 use crate::ast::helpers::{extract_handler_names, match_name_or_attr, SubscriptKind};
-use crate::ast::operations::{extract_all_names, SourceCodeLocator};
+use crate::ast::operations::extract_all_names;
 use crate::ast::relocate::relocate_expr;
 use crate::ast::types::{
     Binding, BindingContext, BindingKind, CheckLocator, FunctionScope, ImportKind, Range, Scope,
@@ -27,6 +27,7 @@ use crate::python::builtins::{BUILTINS, MAGIC_GLOBALS};
 use crate::python::future::ALL_FEATURE_NAMES;
 use crate::settings::types::PythonVersion;
 use crate::settings::Settings;
+use crate::source_code_locator::SourceCodeLocator;
 use crate::visibility::{module_visibility, transition_scope, Modifier, Visibility, VisibleScope};
 use crate::{
     docstrings, flake8_bugbear, flake8_builtins, flake8_comprehensions, flake8_print, pep8_naming,

src/check_tokens.rs

@@ -2,9 +2,9 @@
 
 use rustpython_parser::lexer::{LexResult, Tok};
 
-use crate::ast::operations::SourceCodeLocator;
 use crate::checks::{Check, CheckCode};
 use crate::flake8_quotes::docstring_detection::StateMachine;
+use crate::source_code_locator::SourceCodeLocator;
 use crate::{flake8_quotes, pycodestyle, Settings};
 
 pub fn check_tokens(

src/flake8_quotes/checks.rs

@@ -1,9 +1,9 @@
 use rustpython_ast::Location;
 
-use crate::ast::operations::SourceCodeLocator;
 use crate::ast::types::Range;
 use crate::checks::{Check, CheckKind};
 use crate::flake8_quotes::settings::{Quote, Settings};
+use crate::source_code_locator::SourceCodeLocator;
 
 fn good_single(quote: &Quote) -> char {
     match quote {

src/lib.rs

@@ -14,7 +14,7 @@ use crate::linter::{check_path, tokenize};
 use crate::message::Message;
 use crate::settings::configuration::Configuration;
 
-pub mod ast;
+mod ast;
 mod autofix;
 pub mod cache;
 pub mod check_ast;
@@ -44,6 +44,7 @@ mod pyflakes;
 mod python;
 mod pyupgrade;
 pub mod settings;
+pub mod source_code_locator;
 pub mod visibility;
 
 /// Run ruff over Python source code directly.

src/linter.rs

@@ -9,7 +9,6 @@ use log::debug;
 use rustpython_parser::lexer::LexResult;
 use rustpython_parser::{lexer, parser};
 
-use crate::ast::operations::SourceCodeLocator;
 use crate::ast::types::Range;
 use crate::autofix::fixer;
 use crate::autofix::fixer::fix_file;
@@ -21,6 +20,7 @@ use crate::code_gen::SourceGenerator;
 use crate::message::Message;
 use crate::noqa::add_noqa;
 use crate::settings::Settings;
+use crate::source_code_locator::SourceCodeLocator;
 use crate::{cache, fs, noqa};
 
 /// Collect tokens up to and including the first error.

src/pycodestyle/checks.rs

@@ -2,9 +2,9 @@ use itertools::izip;
 use rustpython_ast::Location;
 use rustpython_parser::ast::{Cmpop, Constant, Expr, ExprKind, Unaryop};
 
-use crate::ast::operations::SourceCodeLocator;
 use crate::ast::types::{CheckLocator, Range};
 use crate::checks::{Check, CheckKind, RejectedCmpop};
+use crate::source_code_locator::SourceCodeLocator;
 
 fn is_ambiguous_name(name: &str) -> bool {
     name == "l" || name == "I" || name == "O"

src/pyflakes/fixes.rs

@@ -2,10 +2,10 @@ use anyhow::Result;
 use libcst_native::{Codegen, ImportNames, NameOrAttribute, SmallStatement, Statement};
 use rustpython_ast::Stmt;
 
-use crate::ast::operations::SourceCodeLocator;
 use crate::ast::types::Range;
 use crate::autofix::{helpers, Fix};
 use crate::cst::helpers::compose_module_path;
+use crate::source_code_locator::SourceCodeLocator;
 
 /// Generate a Fix to remove any unused imports from an `import` statement.
 pub fn remove_unused_imports(

src/pyupgrade/fixes.rs

@@ -4,9 +4,9 @@ use rustpython_parser::lexer;
 use rustpython_parser::lexer::Tok;
 
 use crate::ast::helpers;
-use crate::ast::operations::SourceCodeLocator;
 use crate::ast::types::Range;
 use crate::autofix::Fix;
+use crate::source_code_locator::SourceCodeLocator;
 
 /// Generate a fix to remove a base from a ClassDef statement.
 pub fn remove_class_def_base(

src/source_code_locator.rs

@@ -0,0 +1,114 @@
+//! Struct used to efficiently slice source code at (row, column) Locations.
+
+use once_cell::unsync::OnceCell;
+use rustpython_ast::Location;
+
+use crate::ast::types::Range;
+
+pub struct SourceCodeLocator<'a> {
+    contents: &'a str,
+    offsets: OnceCell<Vec<Vec<usize>>>,
+}
+
+pub fn compute_offsets(contents: &str) -> Vec<Vec<usize>> {
+    let mut offsets = vec![vec![]];
+    let mut line_index = 0;
+    let mut char_index = 0;
+    let mut newline = false;
+    for (i, char) in contents.char_indices() {
+        offsets[line_index].push(i);
+
+        newline = char == '\n';
+        if newline {
+            line_index += 1;
+            offsets.push(vec![]);
+            char_index = i + char.len_utf8();
+        }
+    }
+    // If we end in a newline, add an extra character to indicate the start of that line.
+    if newline {
+        offsets[line_index].push(char_index);
+    }
+    offsets
+}
+
+impl<'a> SourceCodeLocator<'a> {
+    pub fn new(contents: &'a str) -> Self {
+        SourceCodeLocator {
+            contents,
+            offsets: OnceCell::new(),
+        }
+    }
+
+    fn get_or_init_offsets(&self) -> &Vec<Vec<usize>> {
+        self.offsets.get_or_init(|| compute_offsets(self.contents))
+    }
+
+    pub fn slice_source_code_at(&self, location: &Location) -> &'a str {
+        let offsets = self.get_or_init_offsets();
+        let offset = offsets[location.row() - 1][location.column() - 1];
+        &self.contents[offset..]
+    }
+
+    pub fn slice_source_code_range(&self, range: &Range) -> &'a str {
+        let offsets = self.get_or_init_offsets();
+        let start = offsets[range.location.row() - 1][range.location.column() - 1];
+        let end = offsets[range.end_location.row() - 1][range.end_location.column() - 1];
+        &self.contents[start..end]
+    }
+
+    pub fn partition_source_code_at(
+        &self,
+        outer: &Range,
+        inner: &Range,
+    ) -> (&'a str, &'a str, &'a str) {
+        let offsets = self.get_or_init_offsets();
+        let outer_start = offsets[outer.location.row() - 1][outer.location.column() - 1];
+        let outer_end = offsets[outer.end_location.row() - 1][outer.end_location.column() - 1];
+        let inner_start = offsets[inner.location.row() - 1][inner.location.column() - 1];
+        let inner_end = offsets[inner.end_location.row() - 1][inner.end_location.column() - 1];
+        (
+            &self.contents[outer_start..inner_start],
+            &self.contents[inner_start..inner_end],
+            &self.contents[inner_end..outer_end],
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::source_code_locator::SourceCodeLocator;
+
+    #[test]
+    fn source_code_locator_init() {
+        let content = "x = 1";
+        let locator = SourceCodeLocator::new(content);
+        let offsets = locator.get_or_init_offsets();
+        assert_eq!(offsets.len(), 1);
+        assert_eq!(offsets[0], [0, 1, 2, 3, 4]);
+
+        let content = "x = 1\n";
+        let locator = SourceCodeLocator::new(content);
+        let offsets = locator.get_or_init_offsets();
+        assert_eq!(offsets.len(), 2);
+        assert_eq!(offsets[0], [0, 1, 2, 3, 4, 5]);
+        assert_eq!(offsets[1], [6]);
+
+        let content = "x = 1\ny = 2\nz = x + y\n";
+        let locator = SourceCodeLocator::new(content);
+        let offsets = locator.get_or_init_offsets();
+        assert_eq!(offsets.len(), 4);
+        assert_eq!(offsets[0], [0, 1, 2, 3, 4, 5]);
+        assert_eq!(offsets[1], [6, 7, 8, 9, 10, 11]);
+        assert_eq!(offsets[2], [12, 13, 14, 15, 16, 17, 18, 19, 20, 21]);
+        assert_eq!(offsets[3], [22]);
+
+        let content = "# \u{4e9c}\nclass Foo:\n    \"\"\".\"\"\"";
+        let locator = SourceCodeLocator::new(content);
+        let offsets = locator.get_or_init_offsets();
+        assert_eq!(offsets.len(), 3);
+        assert_eq!(offsets[0], [0, 1, 2, 5]);
+        assert_eq!(offsets[1], [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
+        assert_eq!(offsets[2], [17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27]);
+    }
+}