import type { AggregateFunctionType } from '../../../model/malloy_types';
import { FieldReference } from '../query-items/field-references';
import type { ExprValue } from '../types/expr-value';
import { ExpressionDef } from '../types/expression-def';
import type { FieldSpace } from '../types/field-space';
import type { JoinPath } from '../types/lookup-result';
export declare abstract class ExprAggregateFunction extends ExpressionDef {
    readonly func: AggregateFunctionType;
    elementType: string;
    source?: FieldReference;
    expr?: ExpressionDef;
    explicitSource?: boolean;
    legalChildTypes: import("../../../model/malloy_types").TypeDesc[];
    constructor(func: AggregateFunctionType, expr?: ExpressionDef, explicitSource?: boolean);
    abstract returns(fromExpr: ExprValue): ExprValue;
    getExpression(fs: FieldSpace): ExprValue;
    isSymmetricFunction(): boolean;
    getJoinUsage(fs: FieldSpace): JoinPath[];
}