1 files changed, 91 insertions, 2 deletions

diff --git a/py/objstr.c b/py/objstr.c
index 83fd002d1e..27f6d9cd6f 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -667,6 +667,7 @@ STATIC mp_obj_t str_uni_strip(int type, uint n_args, const mp_obj_t *args) {
     for (machine_uint_t len = orig_str_len; len > 0; len--) {
         if (find_subbytes(chars_to_del, chars_to_del_len, &orig_str[i], 1, 1) == NULL) {
             if (!first_good_char_pos_set) {
+                first_good_char_pos_set = true;
                 first_good_char_pos = i;
                 if (type == LSTRIP) {
                     last_good_char_pos = orig_str_len - 1;
@@ -676,14 +677,13 @@ STATIC mp_obj_t str_uni_strip(int type, uint n_args, const mp_obj_t *args) {
                     last_good_char_pos = i;
                     break;
                 }
-                first_good_char_pos_set = true;
             }
             last_good_char_pos = i;
         }
         i += delta;
     }
 
-    if (first_good_char_pos == 0 && last_good_char_pos == 0) {
+    if (!first_good_char_pos_set) {
         // string is all whitespace, return ''
         return MP_OBJ_NEW_QSTR(MP_QSTR_);
     }
@@ -691,6 +691,12 @@ STATIC mp_obj_t str_uni_strip(int type, uint n_args, const mp_obj_t *args) {
     assert(last_good_char_pos >= first_good_char_pos);
     //+1 to accomodate the last character
     machine_uint_t stripped_len = last_good_char_pos - first_good_char_pos + 1;
+    if (stripped_len == orig_str_len) {
+        // If nothing was stripped, don't bother to dup original string
+        // TODO: watch out for this case when we'll get to bytearray.strip()
+        assert(first_good_char_pos == 0);
+        return args[0];
+    }
     return mp_obj_new_str_of_type(self_type, orig_str + first_good_char_pos, stripped_len);
 }
 
@@ -1496,6 +1502,79 @@ STATIC mp_obj_t str_upper(mp_obj_t self_in) {
     return str_caseconv(CASE_UPPER, self_in);
 }
 
+enum { IS_SPACE, IS_ALPHA, IS_DIGIT, IS_UPPER, IS_LOWER };
+
+STATIC mp_obj_t str_uni_istype(int type, mp_obj_t self_in) {
+    GET_STR_DATA_LEN(self_in, self_data, self_len);
+
+    if (self_len == 0) {
+        return mp_const_false; // default to False for empty str
+    }
+
+    typedef bool (*check_function)(unichar);
+    check_function f;
+
+    if (type != IS_UPPER && type != IS_LOWER) {
+        switch (type) {
+            case IS_SPACE: f = &unichar_isspace; break;
+            case IS_ALPHA: f = &unichar_isalpha; break;
+            case IS_DIGIT: f = &unichar_isdigit; break;
+            default:
+                nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "unknown type provided for str_uni_istype"));
+        }
+
+        for (int i = 0; i < self_len; i++) {
+            if (!f(*self_data++)) {
+                return mp_const_false;
+            }
+        }
+    } else {
+        switch (type) {
+            case IS_UPPER: f = &unichar_isupper; break;
+            case IS_LOWER: f = &unichar_islower; break;
+            default:
+                nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "unknown type provided for str_uni_istype"));
+        }
+
+        bool contains_alpha = false;
+
+        for (int i = 0; i < self_len; i++) { // only check alphanumeric characters
+            if (unichar_isalpha(*self_data++)) {
+                contains_alpha = true;
+                if (!f(*(self_data-1))) {
+                    return mp_const_false; // we already incremented
+                }
+            }
+        }
+
+        if (!contains_alpha) {
+            return mp_const_false;
+        }
+    }
+
+    return mp_const_true;
+}
+
+STATIC mp_obj_t str_isspace(mp_obj_t self_in) {
+    return str_uni_istype(IS_SPACE, self_in);
+}
+
+STATIC mp_obj_t str_isalpha(mp_obj_t self_in) {
+    return str_uni_istype(IS_ALPHA, self_in);
+}
+
+STATIC mp_obj_t str_isdigit(mp_obj_t self_in) {
+    return str_uni_istype(IS_DIGIT, self_in);
+}
+
+STATIC mp_obj_t str_isupper(mp_obj_t self_in) {
+    return str_uni_istype(IS_UPPER, self_in);
+}
+
+STATIC mp_obj_t str_islower(mp_obj_t self_in) {
+    return str_uni_istype(IS_LOWER, self_in);
+}
+
 #if MICROPY_CPYTHON_COMPAT
 // These methods are superfluous in the presense of str() and bytes()
 // constructors.
@@ -1563,6 +1642,11 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(str_partition_obj, str_partition);
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(str_rpartition_obj, str_rpartition);
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_lower_obj, str_lower);
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_upper_obj, str_upper);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_isspace_obj, str_isspace);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_isalpha_obj, str_isalpha);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_isdigit_obj, str_isdigit);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_isupper_obj, str_isupper);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(str_islower_obj, str_islower);
 
 STATIC const mp_map_elem_t str_locals_dict_table[] = {
 #if MICROPY_CPYTHON_COMPAT
@@ -1588,6 +1672,11 @@ STATIC const mp_map_elem_t str_locals_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_rpartition), (mp_obj_t)&str_rpartition_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_lower), (mp_obj_t)&str_lower_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_upper), (mp_obj_t)&str_upper_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_isspace), (mp_obj_t)&str_isspace_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_isalpha), (mp_obj_t)&str_isalpha_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_isdigit), (mp_obj_t)&str_isdigit_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_isupper), (mp_obj_t)&str_isupper_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_islower), (mp_obj_t)&str_islower_obj },
 };
 
 STATIC MP_DEFINE_CONST_DICT(str_locals_dict, str_locals_dict_table);