import { FormlyFieldConfigCache } from '../../models';
import { FormlyExtension } from '../../models';
export declare class FieldExpressionExtension implements FormlyExtension {
    onPopulate(field: FormlyFieldConfigCache): void;
    postPopulate(field: FormlyFieldConfigCache): void;
    protected parseExpressions(field: FormlyFieldConfigCache, path: string, expr: any): {
        callback: (ignoreCache?: boolean) => boolean;
    };
    protected _evalStringExpression(expression: string, argNames: string[]): any;
    private checkExpressions;
    private changeDisabledState;
    private changeHideState;
    private evalExpr;
    private emitExpressionChanges;
    private _evalExpressionPath;
}