Method find_var_definition

src/symbol_map/mod.rs:631–664

Find the most recent definition of `$var_name` before `cursor_offset` within the same scope. The caller should obtain `scope_start` via [`find_enclosing_scope`].

(
        &self,
        var_name: &str,
        cursor_offset: u32,
        scope_start: u32,
    )

    /// The caller should obtain `scope_start` via
    /// [`find_enclosing_scope`].
    pub fn find_var_definition(
        &self,
        var_name: &str,
        cursor_offset: u32,
        scope_start: u32,
    ) -> Option<&VarDefSite> {
        // Find all visible definitions for this variable in this scope.
        // Prefer the most recent one, but if a shallower (outer) definition
        // exists, prefer it over a deeper (conditional) one when the cursor
        // is outside the conditional block.
        let mut best: Option<&VarDefSite> = None;
        for d in self.var_defs.iter() {
            if d.name != var_name
                || d.scope_start != scope_start
                || d.effective_from > cursor_offset
            {
                continue;
            }
            match best {
                None => best = Some(d),
                Some(prev) => {
                    if d.nesting_depth <= prev.nesting_depth {
                        // Same or shallower depth: more recent wins.
                        best = Some(d);
                    } else if cursor_offset <= d.block_end {
                        // Deeper, but cursor is inside the block: use it.
                        best = Some(d);
                    }
                    // Deeper and cursor is past the block: keep prev.
                }
            }
        }
        best
    }

    /// Return the `effective_from` offset of the most recent definition
    /// of `$var_name` that is visible at `cursor_offset`, or `0` if no