import { type ATN } from "antlr4ng";
/**
 * What can legally come next at the caret:
 *  - `tokens`: candidate terminal token TYPES (keywords/punctuation/literals) collectable there.
 *  - `rules`: the *preferred* rule indices (name/column/table reference slots) reachable there;
 *    the editor resolves these with schema-aware names instead of enumerating raw tokens.
 */
export interface Candidates {
    tokens: Set<number>;
    rules: Set<number>;
}
/** The minimal token view the walk needs: each token's antlr type + channel, in source order. Both
 *  antlr's `Token` and our neutral `Token` (src/token/token.ts) satisfy it, so the walk runs over
 *  the document's OWN already-lexed token stream, never a re-parse. */
export interface WalkToken {
    type: number;
    channel: number;
}
/**
 * Our own ATN candidate-collection walk — a reimplementation of antlr4-c3's
 * `CodeCompletionCore` (`collectCandidates` / `processRule` / `translateStackToRuleIndex`),
 * in our own naming/structure, over the antlr4ng ATN API. No `antlr4-c3` dependency.
 *
 * The idea: ANTLR compiles each parser rule into an ATN (a state graph). Starting at the entry
 * rule's start state we DFS the graph, threading a `tokenListIndex` (how many of the real input
 * tokens before the caret we have consumed) so impossible paths get pruned. At the caret
 * (`tokenListIndex === caretListIndex`) every terminal transition's label contributes its token
 * types as candidates — unless the current rule call stack is inside a preferred (name/column)
 * rule, in which case we record that rule and suppress the raw tokens it subsumes.
 *
 * `atn` is the dialect's parser ATN (input-independent, a per-dialect static) and `tokens` is the
 * document's own lexed token stream up to (at least) the caret; the walk consumes only their `type`
 * and `channel`, so it reuses the already-parsed tokens rather than re-lexing the source.
 */
export declare function collectCandidates(atn: ATN, startRuleIndex: number, tokens: readonly WalkToken[], caretTokenIndex: number, preferredRules: Set<number>, ignoredTokens: Set<number>): Candidates;