import { HashSet } from "things";
import { int, nat } from "things";
import { Hash } from "things";
import { Grammar, Rule } from "./cfg.js";
export declare class Item {
    rule: nat;
    dot: nat;
    lookahead: int;
    constructor(rule: nat, dot: nat, lookahead: int);
    symbolAfterDot(rhs: int[]): int;
    moveDot(): Item;
}
export declare const ItemHash: Hash<Item>;
export type Items = HashSet<Item>;
export declare function nonterminalsOfGrammar(grammar: Grammar): Set<int>;
export declare function terminalsOfGrammar(grammar: Grammar): Set<int>;
export declare function groupRules(grammar: Grammar): Map<int, nat[]>;
export type XGrammar = {
    grammar: Grammar;
    terminals: Set<int>;
    nonterminals: Set<int>;
    grouped: Map<int, nat[]>;
    first: Map<int, Set<int>>;
    startRule: Rule;
};
export declare function computeFirst(nonterminals: Set<int>, grammar: Grammar): Map<int, Set<int>>;
export declare function extendGrammar(grammar: Grammar): XGrammar;
export declare function firstFrom(xgrammar: XGrammar, rhs: int[], lookahead: int, dot: nat): Set<int>;
export declare function computeClosure(xgrammar: XGrammar, items: Items): void;
export declare function computeGoto(xgrammar: XGrammar, items: Items, symbol: int): Items;
export type LR1Graph = {
    states: Items[];
    symbols: int[];
    graph: Map<nat, Map<int, nat>>;
};
export declare function computeLR1Graph(xgrammar: XGrammar): LR1Graph;
export declare enum ActionKind {
    SHIFT = 0,
    REDUCE = 1,
    ACCEPT = 2
}
export type Shift = {
    kind: ActionKind.SHIFT;
    state: nat;
};
export type Reduce = {
    kind: ActionKind.REDUCE;
    rule: nat;
};
export type Accept = {
    kind: ActionKind.ACCEPT;
};
export type Action = Shift | Reduce | Accept;
export declare const Action: Hash<Action>;
export type Actions = Map<int, HashSet<Action>>;
export declare function computeActionsOfState(xgrammar: XGrammar, lr1: LR1Graph, stateIndex: nat): Actions;
export declare function filterConflictingActions(actions: Actions): Actions;
export declare function isAccepting(actions: Actions): boolean;
export declare function nextTerminalsOf(actions: Actions): Set<int>;