import { Expression, Metadata, Statement } from "../ir";
import { Machine, State } from "../vm";
import { Environment, World } from "../world";
import { CrochetValue, CrochetType } from "./0-core";
import { Meta } from "../ir";
export declare class ContractCondition {
    readonly meta: Meta;
    readonly tag: string;
    readonly expr: Expression;
    constructor(meta: Meta, tag: string, expr: Expression);
    is_valid(state: State): Machine;
    format_error(): string;
}
export declare class Contract {
    readonly pre: ContractCondition[];
    readonly post: ContractCondition[];
    constructor(pre: ContractCondition[], post: ContractCondition[]);
    check_pre(state: State, name: string, params: string[], args: CrochetValue[]): Machine;
    check_post(state0: State, name: string, params: string[], args: CrochetValue[], result: CrochetValue): Machine;
}
export interface IProcedure {
    location_message: string;
    documentation: string;
    contract: Contract;
    invoke(state: State, values: CrochetValue[]): Machine;
}
export declare class Procedure {
    readonly name: string;
    readonly arity: number;
    private branches;
    private versions;
    constructor(name: string, arity: number);
    select(values: CrochetValue[]): ProcedureBranch | null;
    add(types: CrochetType[], procedure: IProcedure): void;
    override(types: CrochetType[], procedure: IProcedure): void;
    rollback(version?: number): void;
    select_exact(types: CrochetType[], branches?: ProcedureBranch[]): Generator<ProcedureBranch, void, unknown>;
    select_subtype(types: CrochetType[], branches?: ProcedureBranch[]): Generator<ProcedureBranch, void, unknown>;
    select_matching(type: CrochetType, branches?: ProcedureBranch[]): ProcedureBranch[];
    assert_no_duplicates(types: CrochetType[], branches?: ProcedureBranch[]): void;
}
export declare class ProcedureBranch {
    readonly types: CrochetType[];
    readonly procedure: IProcedure;
    constructor(types: CrochetType[], procedure: IProcedure);
    compare(branch: ProcedureBranch): number;
    accepts(values: CrochetValue[]): boolean;
    get simple_repr(): string;
    get location_message(): string;
    get full_repr(): string;
}
export declare type NativeProcedureFn = (state: State, ...args: CrochetValue[]) => Machine;
export declare class NativeProcedure implements IProcedure {
    readonly meta: Metadata;
    readonly env: Environment;
    readonly name: string;
    readonly parameter_names: string[];
    readonly parameters: string[];
    readonly foreign_name: string;
    readonly contract: Contract;
    constructor(meta: Metadata, env: Environment, name: string, parameter_names: string[], parameters: string[], foreign_name: string, contract: Contract);
    get full_name(): string;
    get location_message(): string;
    get documentation(): string;
    invoke(state0: State, values: CrochetValue[]): Machine;
}
export declare class CrochetProcedure implements IProcedure {
    readonly meta: Metadata;
    readonly env: Environment;
    readonly world: World;
    readonly name: string;
    readonly parameters: string[];
    readonly body: Statement[];
    readonly contract: Contract;
    constructor(meta: Metadata, env: Environment, world: World, name: string, parameters: string[], body: Statement[], contract: Contract);
    get full_name(): string;
    get location_message(): string;
    get documentation(): string;
    invoke(state0: State, values: CrochetValue[]): Generator<import("../vm").Mark | import("../vm").Push, CrochetValue, unknown>;
}