pub fn RunPreserve(Source: &str, Options: &Options) -> Result<Option<String>>Expand description
Identify inlinable bindings via the same AST pipeline as Run, but apply
the substitutions as targeted text edits so that every character outside
the affected let binding and its single use-site is preserved verbatim.
Uses no proc_macro2 span APIs; works on stable Rust with the dependency
set already declared in Cargo.toml.
Returns Ok(None) when no bindings were eliminated.