Pass ParserOptions to the parser (#16220)

## Summary

This is part of the preparation for detecting syntax errors in the
parser from https://github.com/astral-sh/ruff/pull/16090/. As suggested
in [this
comment](https://github.com/astral-sh/ruff/pull/16090/#discussion_r1953084509),
I started working on a `ParseOptions` struct that could be stored in the
parser. For this initial refactor, I only made it hold the existing
`Mode` option, but for syntax errors, we will also need it to have a
`PythonVersion`. For that use case, I'm picturing something like a
`ParseOptions::with_python_version` method, so you can extend the
current calls to something like

```rust
ParseOptions::from(mode).with_python_version(settings.target_version)
```

But I thought it was worth adding `ParseOptions` alone without changing
any other behavior first.

Most of the diff is just updating call sites taking `Mode` to take
`ParseOptions::from(Mode)` or those taking `PySourceType`s to take
`ParseOptions::from(PySourceType)`. The interesting changes are in the
new `parser/options.rs` file and smaller parts of `parser/mod.rs` and
`ruff_python_parser/src/lib.rs`.

## Test Plan

Existing tests, this should not change any behavior.

crates/ruff_python_parser/src/parser/expression.rs

@@ -2265,7 +2265,7 @@ impl<'src> Parser<'src> {
             value,
         };
 
-        if self.mode != Mode::Ipython {
+        if self.options.mode != Mode::Ipython {
             self.add_error(ParseErrorType::UnexpectedIpythonEscapeCommand, &command);
         }
 

crates/ruff_python_parser/src/parser/mod.rs

@@ -13,8 +13,11 @@ use crate::token_source::{TokenSource, TokenSourceCheckpoint};
 use crate::{Mode, ParseError, ParseErrorType, TokenKind};
 use crate::{Parsed, Tokens};
 
+pub use crate::parser::options::ParseOptions;
+
 mod expression;
 mod helpers;
+mod options;
 mod pattern;
 mod progress;
 mod recovery;
@@ -32,8 +35,8 @@ pub(crate) struct Parser<'src> {
     /// Stores all the syntax errors found during the parsing.
     errors: Vec<ParseError>,
 
-    /// Specify the mode in which the code will be parsed.
-    mode: Mode,
+    /// Options for how the code will be parsed.
+    options: ParseOptions,
 
     /// The ID of the current token. This is used to track the progress of the parser
     /// to avoid infinite loops when the parser is stuck.
@@ -51,16 +54,20 @@ pub(crate) struct Parser<'src> {
 
 impl<'src> Parser<'src> {
     /// Create a new parser for the given source code.
-    pub(crate) fn new(source: &'src str, mode: Mode) -> Self {
-        Parser::new_starts_at(source, mode, TextSize::new(0))
+    pub(crate) fn new(source: &'src str, options: ParseOptions) -> Self {
+        Parser::new_starts_at(source, TextSize::new(0), options)
     }
 
     /// Create a new parser for the given source code which starts parsing at the given offset.
-    pub(crate) fn new_starts_at(source: &'src str, mode: Mode, start_offset: TextSize) -> Self {
-        let tokens = TokenSource::from_source(source, mode, start_offset);
+    pub(crate) fn new_starts_at(
+        source: &'src str,
+        start_offset: TextSize,
+        options: ParseOptions,
+    ) -> Self {
+        let tokens = TokenSource::from_source(source, options.mode, start_offset);
 
         Parser {
-            mode,
+            options,
             source,
             errors: Vec::new(),
             tokens,
@@ -73,7 +80,7 @@ impl<'src> Parser<'src> {
 
     /// Consumes the [`Parser`] and returns the parsed [`Parsed`].
     pub(crate) fn parse(mut self) -> Parsed<Mod> {
-        let syntax = match self.mode {
+        let syntax = match self.options.mode {
             Mode::Expression | Mode::ParenthesizedExpression => {
                 Mod::Expression(self.parse_single_expression())
             }

crates/ruff_python_parser/src/parser/options.rs

@@ -0,0 +1,41 @@
+use ruff_python_ast::PySourceType;
+
+use crate::{AsMode, Mode};
+
+/// Options for controlling how a source file is parsed.
+///
+/// You can construct a [`ParseOptions`] directly from a [`Mode`]:
+///
+/// ```
+/// use ruff_python_parser::{Mode, ParseOptions};
+///
+/// let options = ParseOptions::from(Mode::Module);
+/// ```
+///
+/// or from a [`PySourceType`]
+///
+/// ```
+/// use ruff_python_ast::PySourceType;
+/// use ruff_python_parser::ParseOptions;
+///
+/// let options = ParseOptions::from(PySourceType::Python);
+/// ```
+#[derive(Debug)]
+pub struct ParseOptions {
+    /// Specify the mode in which the code will be parsed.
+    pub(crate) mode: Mode,
+}
+
+impl From<Mode> for ParseOptions {
+    fn from(mode: Mode) -> Self {
+        Self { mode }
+    }
+}
+
+impl From<PySourceType> for ParseOptions {
+    fn from(source_type: PySourceType) -> Self {
+        Self {
+            mode: source_type.as_mode(),
+        }
+    }
+}

crates/ruff_python_parser/src/parser/statement.rs

@@ -304,7 +304,7 @@ impl<'src> Parser<'src> {
                         op,
                         start,
                     ))
-                } else if self.mode == Mode::Ipython && self.at(TokenKind::Question) {
+                } else if self.options.mode == Mode::Ipython && self.at(TokenKind::Question) {
                     Stmt::IpyEscapeCommand(
                         self.parse_ipython_help_end_escape_command_statement(&parsed_expr),
                     )
@@ -932,7 +932,7 @@ impl<'src> Parser<'src> {
         };
 
         let range = self.node_range(start);
-        if self.mode != Mode::Ipython {
+        if self.options.mode != Mode::Ipython {
             self.add_error(ParseErrorType::UnexpectedIpythonEscapeCommand, range);
         }
 

crates/ruff_python_parser/src/parser/tests.rs

@@ -1,11 +1,11 @@
-use crate::{parse, parse_expression, parse_module, Mode};
+use crate::{parse, parse_expression, parse_module, Mode, ParseOptions};
 
 #[test]
 fn test_modes() {
     let source = "a[0][1][2][3][4]";
 
-    assert!(parse(source, Mode::Expression).is_ok());
-    assert!(parse(source, Mode::Module).is_ok());
+    assert!(parse(source, ParseOptions::from(Mode::Expression)).is_ok());
+    assert!(parse(source, ParseOptions::from(Mode::Module)).is_ok());
 }
 
 #[test]
@@ -129,7 +129,7 @@ foo.bar[0].baz[1]??
 foo.bar[0].baz[2].egg??
 "
         .trim(),
-        Mode::Ipython,
+        ParseOptions::from(Mode::Ipython),
     )
     .unwrap();
     insta::assert_debug_snapshot!(parsed.syntax());