/**
 * ExprNode to MEL Renderer
 *
 * Converts ExprNode AST to MEL expression syntax.
 *
 * @example
 * // { kind: "lit", value: 5 } -> "5"
 * // { kind: "get", path: "count" } -> "count"
 * // { kind: "add", left: { kind: "get", path: "x" }, right: { kind: "lit", value: 1 } } -> "add(x, 1)"
 * // { kind: "gt", left: { kind: "get", path: "count" }, right: { kind: "lit", value: 0 } } -> "gt(count, 0)"
 */
/**
 * ExprNode type (subset from core package)
 */
export type ExprNode = {
    kind: "lit";
    value: unknown;
} | {
    kind: "get";
    path: string;
} | {
    kind: "eq";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "neq";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "gt";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "gte";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "lt";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "lte";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "and";
    args: ExprNode[];
} | {
    kind: "or";
    args: ExprNode[];
} | {
    kind: "not";
    arg: ExprNode;
} | {
    kind: "if";
    cond: ExprNode;
    then: ExprNode;
    else: ExprNode;
} | {
    kind: "add";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "sub";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "mul";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "div";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "mod";
    left: ExprNode;
    right: ExprNode;
} | {
    kind: "concat";
    args: ExprNode[];
} | {
    kind: "substring";
    str: ExprNode;
    start: ExprNode;
    end?: ExprNode;
} | {
    kind: "trim";
    str: ExprNode;
} | {
    kind: "len";
    arg: ExprNode;
} | {
    kind: "at";
    array: ExprNode;
    index: ExprNode;
} | {
    kind: "first";
    array: ExprNode;
} | {
    kind: "last";
    array: ExprNode;
} | {
    kind: "slice";
    array: ExprNode;
    start: ExprNode;
    end?: ExprNode;
} | {
    kind: "includes";
    array: ExprNode;
    item: ExprNode;
} | {
    kind: "filter";
    array: ExprNode;
    predicate: ExprNode;
} | {
    kind: "map";
    array: ExprNode;
    mapper: ExprNode;
} | {
    kind: "find";
    array: ExprNode;
    predicate: ExprNode;
} | {
    kind: "every";
    array: ExprNode;
    predicate: ExprNode;
} | {
    kind: "some";
    array: ExprNode;
    predicate: ExprNode;
} | {
    kind: "append";
    array: ExprNode;
    items: ExprNode[];
} | {
    kind: "object";
    fields: Record<string, ExprNode>;
} | {
    kind: "field";
    object: ExprNode;
    property: string;
} | {
    kind: "keys";
    obj: ExprNode;
} | {
    kind: "values";
    obj: ExprNode;
} | {
    kind: "entries";
    obj: ExprNode;
} | {
    kind: "merge";
    objects: ExprNode[];
} | {
    kind: "typeof";
    arg: ExprNode;
} | {
    kind: "isNull";
    arg: ExprNode;
} | {
    kind: "coalesce";
    args: ExprNode[];
};
/**
 * Renders an ExprNode to MEL expression syntax string.
 *
 * @param expr - The ExprNode to render
 * @returns MEL expression syntax string
 */
export declare function renderExprNode(expr: ExprNode): string;