Struct Scope 

pub struct Scope {

    pub expression: Expression,
    pub scope_type: ScopeType,
    pub sources: HashMap<String, SourceInfo>,
    pub lateral_sources: HashMap<String, SourceInfo>,
    pub cte_sources: HashMap<String, SourceInfo>,
    pub outer_columns: Vec<String>,
    pub can_be_correlated: bool,
    pub subquery_scopes: Vec<Scope>,
    pub derived_table_scopes: Vec<Scope>,
    pub cte_scopes: Vec<Scope>,
    pub udtf_scopes: Vec<Scope>,
    pub table_scopes: Vec<Scope>,
    pub union_scopes: Vec<Scope>,
    /* private fields */
}

Represents a scope in a SQL query

A scope is the context of a SELECT statement and its sources. Scopes can be nested (subqueries, CTEs, derived tables) and form a tree.

Fields

expression: Expression

The expression at the root of this scope

scope_type: ScopeType

Type of this scope relative to its parent

sources: HashMap<String, SourceInfo>

Mapping of source names to their info

lateral_sources: HashMap<String, SourceInfo>

Sources from LATERAL views (have access to preceding sources)

cte_sources: HashMap<String, SourceInfo>

CTE sources available to this scope

outer_columns: Vec<String>

If this is a derived table or CTE with alias columns, this is that list e.g., SELECT * FROM (SELECT ...) AS y(col1, col2) => [“col1”, “col2”]

can_be_correlated: bool

Whether this scope can potentially be correlated (true for subqueries and UDTFs)

subquery_scopes: Vec<Scope>

Child subquery scopes

derived_table_scopes: Vec<Scope>

Child derived table scopes

cte_scopes: Vec<Scope>

Child CTE scopes

udtf_scopes: Vec<Scope>

Child UDTF (User Defined Table Function) scopes

table_scopes: Vec<Scope>

Combined derived_table_scopes + udtf_scopes in definition order

union_scopes: Vec<Scope>

Union/set operation scopes (left and right)

Implementations

impl Scope

pub fn new(expression: Expression) -> Self

Create a new root scope

pub fn branch(&self, expression: Expression, scope_type: ScopeType) -> Self

Create a child scope branching from this one

pub fn branch_with_options( &self, expression: Expression, scope_type: ScopeType, sources: Option<HashMap<String, SourceInfo>>, lateral_sources: Option<HashMap<String, SourceInfo>>, outer_columns: Option<Vec<String>>, ) -> Self

Create a child scope with additional options

pub fn clear_cache(&mut self)

Clear all cached properties

pub fn add_source( &mut self, name: String, expression: Expression, is_scope: bool, )

Add a source to this scope

pub fn add_lateral_source( &mut self, name: String, expression: Expression, is_scope: bool, )

Add a lateral source to this scope

pub fn add_cte_source(&mut self, name: String, expression: Expression)

Add a CTE source to this scope

pub fn rename_source(&mut self, old_name: &str, new_name: String)

Rename a source

pub fn remove_source(&mut self, name: &str)

Remove a source

pub fn columns(&mut self) -> &[ColumnRef]

Collect all column references in this scope

pub fn source_names(&self) -> HashSet<String>

Get all source names in this scope

pub fn external_columns(&mut self) -> Vec<ColumnRef>

Get columns that reference sources outside this scope

pub fn local_columns(&mut self) -> Vec<ColumnRef>

Get columns that reference sources in this scope (not external)

pub fn unqualified_columns(&mut self) -> Vec<ColumnRef>

Get unqualified columns (columns without table qualifier)

pub fn source_columns(&mut self, source_name: &str) -> Vec<ColumnRef>

Get columns for a specific source

pub fn is_correlated_subquery(&mut self) -> bool

Determine if this scope is a correlated subquery

A subquery is correlated if:

1. It can be correlated (is a subquery or UDTF), AND
2. It references columns from outer scopes

pub fn is_subquery(&self) -> bool

Check if this is a subquery scope

pub fn is_derived_table(&self) -> bool

Check if this is a derived table scope

pub fn is_cte(&self) -> bool

Check if this is a CTE scope

pub fn is_root(&self) -> bool

Check if this is the root scope

pub fn is_udtf(&self) -> bool

Check if this is a UDTF scope

pub fn is_union(&self) -> bool

Check if this is a union/set operation scope

pub fn traverse(&self) -> Vec<&Scope>

Traverse all scopes in this tree (depth-first post-order)

pub fn ref_count(&self) -> HashMap<usize, usize>

Count references to each scope in this tree

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

Formats the value using the given formatter.