SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "foo"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE " "
        CLOSURE_EXPR
          PARAM_LIST
            PIPE "|"
            PIPE "|"
          WHITESPACE " "
          RET_TYPE
            THIN_ARROW "->"
            WHITESPACE " "
            PATH_TYPE
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "A"
          ERROR
            R_ANGLE ">"
          WHITESPACE " "
          BLOCK_EXPR
            STMT_LIST
              L_CURLY "{"
              WHITESPACE " "
              LET_STMT
                LET_KW "let"
                WHITESPACE " "
                IDENT_PAT
                  NAME
                    IDENT "x"
                WHITESPACE " "
                EQ "="
                WHITESPACE " "
                LITERAL
                  INT_NUMBER "1"
                SEMICOLON ";"
              WHITESPACE " "
              R_CURLY "}"
        WHITESPACE " "
        R_CURLY "}"
  WHITESPACE "\n"
error 18: expected a curly brace
