Module introduce_variable 

Introduce-variable recipe: extract an expression at a given range into a named variable binding.

Algorithm:

1. Parse the file with tree-sitter.
2. Find the innermost complete expression node covering the given byte range.
3. Walk up to the parent statement of that expression.
4. Insert let <name> = <expr>; (or the language-appropriate binding) before the statement.
5. Replace the original expression text with <name>.

Language-specific keyword mapping (everything else uses let):

• Python: <name> = <expr> (no keyword)
• JavaScript / TypeScript: const <name> = <expr>;
• Rust, Go, Swift, Kotlin, Scala, Dart, etc.: let <name> = <expr>;

Structs

ByteRange

A byte range selected by the user.

IntroduceVariableOutcome

Outcome of a successful introduce-variable plan.

Functions

parse_line_col_range

Parse a line:col-line:col range string into a byte range.

plan_introduce_variable

Build an introduce-variable plan without touching the filesystem.