^^&&^^

Edit File: ast.py

# AST nodes have this structure:
# {"type": <node type>", children: [], "value": ""}

def comparator(name, first, second):
    return {'type': 'comparator', 'children': [first, second], 'value': name}

def current_node():
    return {'type': 'current', 'children': []}

def expref(expression):
    return {'type': 'expref', 'children': [expression]}

def function_expression(name, args):
    return {'type': 'function_expression', 'children': args, 'value': name}

def field(name):
    return {"type": "field", "children": [], "value": name}

def filter_projection(left, right, comparator):
    return {'type': 'filter_projection', 'children': [left, right, comparator]}

def flatten(node):
    return {'type': 'flatten', 'children': [node]}

def identity():
    return {"type": "identity", 'children': []}

def index(index):
    return {"type": "index", "value": index, "children": []}

def index_expression(children):
    return {"type": "index_expression", 'children': children}

def key_val_pair(key_name, node):
    return {"type": "key_val_pair", 'children': [node], "value": key_name}

def literal(literal_value):
    return {'type': 'literal', 'value': literal_value, 'children': []}

def multi_select_dict(nodes):
    return {"type": "multi_select_dict", "children": nodes}

def multi_select_list(nodes):
    return {"type": "multi_select_list", "children": nodes}

def or_expression(left, right):
    return {"type": "or_expression", "children": [left, right]}

def and_expression(left, right):
    return {"type": "and_expression", "children": [left, right]}

def not_expression(expr):
    return {"type": "not_expression", "children": [expr]}

def pipe(left, right):
    return {'type': 'pipe', 'children': [left, right]}

def projection(left, right):
    return {'type': 'projection', 'children': [left, right]}

def subexpression(children):
    return {"type": "subexpression", 'children': children}

def slice(start, end, step):
    return {"type": "slice", "children": [start, end, step]}

def value_projection(left, right):
    return {'type': 'value_projection', 'children': [left, right]}