Struct Scope 

pub struct Scope {
    pub id: usize,
    pub parent: Option<usize>,
    pub kind: ScopeKind,
    pub location: ByteSpan,
    pub symbols: HashSet<String>,
}

A lexical scope in Perl code with hierarchical symbol visibility for Parse/Analyze stages.

Represents a lexical scope boundary (subroutine, block, package) with symbol visibility rules according to Perl’s lexical scoping semantics.

Performance Characteristics

• Scope lookup: O(log n) with parent chain traversal
• Symbol resolution: O(1) per scope level
• Memory: ~64 bytes per scope + symbol set

Perl Scoping Rules

• Global scope: File-level and package symbols
• Package scope: Package-qualified symbols
• Subroutine scope: Local variables and parameters
• Block scope: Lexical variables in control structures
• Lexical precedence: Inner scopes shadow outer scopes

Workflow: Parse/Analyze scope tracking for symbol resolution.

Fields

id: usize

Unique scope identifier for reference tracking

parent: Option<usize>

Parent scope for hierarchical lookup (None for global)

kind: ScopeKind

Classification of scope type

location: ByteSpan

Source location where scope begins

symbols: HashSet<String>

Set of symbol names defined in this scope

Trait Implementations

impl Clone for Scope

fn clone(&self) -> Scope

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Scope

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.