/*
 * call-seq: configure(opts)
 *
 * Configure this State instance with the Hash _opts_, and return
 * itself.
 */
static VALUE cState_configure(VALUE self, VALUE opts)
{
    VALUE tmp;
    GET_STATE(self);
    tmp = rb_convert_type(opts, T_HASH, "Hash", "to_hash");
    if (NIL_P(tmp)) tmp = rb_convert_type(opts, T_HASH, "Hash", "to_h");
    if (NIL_P(tmp)) {
        rb_raise(rb_eArgError, "opts has to be hash like or convertable into a hash");
    }
    opts = tmp;
    tmp = rb_hash_aref(opts, ID2SYM(i_indent));
    if (RTEST(tmp)) {
        int len;
        Check_Type(tmp, T_STRING);
        len = RSTRING_LEN(tmp);
        state->indent = fstrndup(RSTRING_PTR(tmp), len);
        state->indent_len = len;
    }
    tmp = rb_hash_aref(opts, ID2SYM(i_space));
    if (RTEST(tmp)) {
        int len;
        Check_Type(tmp, T_STRING);
        len = RSTRING_LEN(tmp);
        state->space = fstrndup(RSTRING_PTR(tmp), len);
        state->space_len = len;
    }
    tmp = rb_hash_aref(opts, ID2SYM(i_space_before));
    if (RTEST(tmp)) {
        int len;
        Check_Type(tmp, T_STRING);
        len = RSTRING_LEN(tmp);
        state->space_before = fstrndup(RSTRING_PTR(tmp), len);
        state->space_before_len = len;
    }
    tmp = rb_hash_aref(opts, ID2SYM(i_array_nl));
    if (RTEST(tmp)) {
        int len;
        Check_Type(tmp, T_STRING);
        len = RSTRING_LEN(tmp);
        state->array_nl = fstrndup(RSTRING_PTR(tmp), len);
        state->array_nl_len = len;
    }
    tmp = rb_hash_aref(opts, ID2SYM(i_object_nl));
    if (RTEST(tmp)) {
        int len;
        Check_Type(tmp, T_STRING);
        len = RSTRING_LEN(tmp);
        state->object_nl = fstrndup(RSTRING_PTR(tmp), len);
        state->object_nl_len = len;
    }
    tmp = ID2SYM(i_max_nesting);
    state->max_nesting = 19;
    if (option_given_p(opts, tmp)) {
        VALUE max_nesting = rb_hash_aref(opts, tmp);
        if (RTEST(max_nesting)) {
            Check_Type(max_nesting, T_FIXNUM);
            state->max_nesting = FIX2LONG(max_nesting);
        } else {
            state->max_nesting = 0;
        }
    }
    tmp = ID2SYM(i_depth);
    state->depth = 0;
    if (option_given_p(opts, tmp)) {
        VALUE depth = rb_hash_aref(opts, tmp);
        if (RTEST(depth)) {
            Check_Type(depth, T_FIXNUM);
            state->depth = FIX2LONG(depth);
        } else {
            state->depth = 0;
        }
    }
    tmp = rb_hash_aref(opts, ID2SYM(i_allow_nan));
    state->allow_nan = RTEST(tmp);
    tmp = rb_hash_aref(opts, ID2SYM(i_ascii_only));
    state->ascii_only = RTEST(tmp);
    return self;
}