gudusoft.gsqlparser.pp2.island

Class SqlScopeDetector

Object

gudusoft.gsqlparser.pp2.island.SqlScopeDetector

public final class SqlScopeDetector
extends Object

Computes, for every token in a Pp2TokenStream, its SQL query-scope level: how many enclosing subqueries / CTE bodies contain it.

Scope model

A token's SQL scope level is the number of enclosing query parens. A query paren is a ( whose next solid (non-comment) token is SELECT or WITH — i.e. a parenthesised subquery or CTE body. Top-level query tokens are level 0; tokens inside one subquery are level 1; doubly-nested are level 2; and so on.

This makes the model robust and well-defined lexically:

• SELECT * FROM (SELECT * FROM (SELECT 1)) → levels 0, 1, 2.
• SELECT 1 UNION SELECT 2 → all level 0 (set-operation siblings share a scope; no extra query paren is introduced).
• WITH x AS (SELECT 1) SELECT * FROM x → the CTE body is level 1, the outer query level 0.
• SELECT (1 + 2) FROM t → all level 0 (a grouping paren is not a query paren — its next solid token is not SELECT/WITH).

Iterative, read-only

Traversal uses an explicit ArrayDeque of paren frames — never recursion — so a 2000-deep nested-subquery input cannot StackOverflowError (CLAUDE.md iterative-traversal mandate; plan §10.1, §13/R3). The detector does not mutate any Pp2Token, its roles, or the wrapped TSourceToken; it returns a SqlScopeDetector.SqlScopeResult side structure (consistent with S18/S19).

Plan reference: §7.3/S20, §7.4/S20, §10.1, §13/R3.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SqlScopeDetector.SqlScope An immutable subquery/CTE scope (a query paren and its contents).
static class	SqlScopeDetector.SqlScopeResult Per-token SQL scope level plus the list of detected subquery/CTE scopes.

Constructor Summary

Constructors

Constructor and Description
SqlScopeDetector()

Method Summary

Modifier and Type	Method and Description
SqlScopeDetector.SqlScopeResult	detect(Pp2TokenStream stream) Annotate the SQL scope level of every token in stream.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SqlScopeDetector

public SqlScopeDetector()

Method Detail

detect

public SqlScopeDetector.SqlScopeResult detect(Pp2TokenStream stream)

Annotate the SQL scope level of every token in stream.

Parameters:

stream - the token stream; must not be null

Returns:

a SqlScopeDetector.SqlScopeResult indexed by token position; never null

Throws:

NullPointerException - if stream is null