$ sqlfluff --version
sqlfluff, version 3.2.4
$ sqlfluff parse -d snowflake reduce.sql 
[L:  1, P:  1]      |file:
[L:  1, P:  1]      |    statement:
[L:  1, P:  1]      |        select_statement:
[L:  1, P:  1]      |            select_clause:
[L:  1, P:  1]      |                keyword:                                      'SELECT'
[L:  1, P:  7]      |                [META] indent:
[L:  1, P:  7]      |                whitespace:                                   ' '
[L:  1, P:  8]      |                select_clause_element:
[L:  1, P:  8]      |                    column_reference:
[L:  1, P:  8]      |                        naked_identifier:                     'REDUCE'
[L:  1, P: 14]      |                [META] dedent:
[L:  1, P: 14]      |                unparsable:                                   !! Expected: 'Nothing here.'
[L:  1, P: 14]      |                    start_bracket:                            '('
[L:  1, P: 15]      |                    start_square_bracket:                     '['
[L:  1, P: 16]      |                    numeric_literal:                          '1'
[L:  1, P: 17]      |                    comma:                                    ','
[L:  1, P: 18]      |                    numeric_literal:                          '2'
[L:  1, P: 19]      |                    comma:                                    ','
[L:  1, P: 20]      |                    numeric_literal:                          '3'
[L:  1, P: 21]      |                    end_square_bracket:                       ']'
[L:  1, P: 22]      |                    comma:                                    ','
[L:  1, P: 23]      |                    whitespace:                               ' '
[L:  1, P: 24]      |                    numeric_literal:                          '0'
[L:  1, P: 25]      |                    comma:                                    ','
[L:  1, P: 26]      |                    whitespace:                               ' '
[L:  1, P: 27]      |                    start_bracket:                            '('
[L:  1, P: 28]      |                    word:                                     'acc'
[L:  1, P: 31]      |                    comma:                                    ','
[L:  1, P: 32]      |                    whitespace:                               ' '
[L:  1, P: 33]      |                    word:                                     'val'
[L:  1, P: 36]      |                    end_bracket:                              ')'
[L:  1, P: 37]      |                    whitespace:                               ' '
[L:  1, P: 38]      |                    function_assigner:                        '->'
[L:  1, P: 40]      |                    whitespace:                               ' '
[L:  1, P: 41]      |                    word:                                     'acc'
[L:  1, P: 44]      |                    whitespace:                               ' '
[L:  1, P: 45]      |                    plus:                                     '+'
[L:  1, P: 46]      |                    whitespace:                               ' '
[L:  1, P: 47]      |                    word:                                     'val'
[L:  1, P: 50]      |                    end_bracket:                              ')'
[L:  1, P: 51]      |    statement_terminator:                                     ';'
[L:  1, P: 52]      |    [META] end_of_file:

==== parsing violations ====
L:   1 | P:  14 |  PRS | Line 1, Position 14: Found unparsable section: '([1,2,3], 0, (acc,
                       | val) -> acc + val)'