SOURCE_FILE
  ERROR
    LET_KW "let"
    WHITESPACE " "
    IDENT_PAT
      NAME
        IDENT "foo"
    WHITESPACE " "
    EQ "="
    WHITESPACE " "
    CLOSURE_EXPR
      PARAM_LIST
        PIPE "|"
        PARAM
          IDENT_PAT
            NAME
              IDENT "x"
          COLON ":"
          WHITESPACE " "
          PATH_TYPE
            PATH
              PATH_SEGMENT
                NAME_REF
                  IDENT "i32"
        PIPE "|"
      WHITESPACE " "
      BLOCK_EXPR
        STMT_LIST
          L_CURLY "{"
          WHITESPACE "\n    "
          PATH_EXPR
            PATH
              PATH_SEGMENT
                NAME_REF
                  IDENT "x"
          WHITESPACE "\n"
          R_CURLY "}"
    WHITESPACE " "
    LET_ELSE
      ELSE_KW "else"
      WHITESPACE " "
      BLOCK_EXPR
        STMT_LIST
          L_CURLY "{"
          WHITESPACE "\n    "
          EXPR_STMT
            RETURN_EXPR
              RETURN_KW "return"
            SEMICOLON ";"
          WHITESPACE "\n"
          R_CURLY "}"
    SEMICOLON ";"
  WHITESPACE "\n"
error 0: expected an item
error 28: right curly brace `}` before `else` in a `let...else` statement not allowed
