Merge remote-tracking branch 'upstream/master'

9 files changed, 383 insertions, 137 deletions

diff --git a/py/builtin.c b/py/builtin.c
index 2e0627fa5f..93e91072c4 100644
--- a/py/builtin.c
+++ b/py/builtin.c
@@ -375,28 +375,6 @@ STATIC mp_obj_t mp_builtin_sorted(uint n_args, const mp_obj_t *args, mp_map_t *k
 
 MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_sorted_obj, 1, mp_builtin_sorted);
 
-STATIC mp_obj_t mp_builtin_str(mp_obj_t o_in) {
-    vstr_t *vstr = vstr_new();
-    mp_obj_print_helper((void (*)(void*, const char*, ...))vstr_printf, vstr, o_in, PRINT_STR);
-    mp_obj_t s = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
-    vstr_free(vstr);
-    return s;
-}
-
-MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_str_obj, mp_builtin_str);
-
-// TODO: This should be type, this is just quick CPython compat hack
-STATIC mp_obj_t mp_builtin_bytes(uint n_args, const mp_obj_t *args) {
-    if (!MP_OBJ_IS_QSTR(args[0]) && !MP_OBJ_IS_TYPE(args[0], &str_type)) {
-        assert(0);
-    }
-    // Currently, MicroPython strings are mix between CPython byte and unicode
-    // strings. So, conversion is null so far.
-    return args[0];
-}
-
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin_bytes_obj, 1, 3, mp_builtin_bytes);
-
 STATIC mp_obj_t mp_builtin_id(mp_obj_t o_in) {
     return mp_obj_new_int((machine_int_t)o_in);
 }
diff --git a/py/builtinmath.c b/py/builtinmath.c
index fd1368ce3c..59af5a021d 100644
--- a/py/builtinmath.c
+++ b/py/builtinmath.c
@@ -46,9 +46,9 @@ MATH_FUN_1(fabs, fabs)
 MATH_FUN_1(floor, floor) //TODO: delegate to x.__floor__() if x is not a float
 MATH_FUN_2(fmod, fmod)
 //MATH_FUN_1(frexp, frexp)
-MATH_FUN_1(isfinite, isfinite)
-MATH_FUN_1(isinf, isinf)
-MATH_FUN_1(isnan, isnan)
+//MATH_FUN_1(isfinite, isfinite)
+//MATH_FUN_1(isinf, isinf)
+//MATH_FUN_1(isnan, isnan)
 MATH_FUN_1(trunc, trunc)
 
 //TODO: factorial, fsum, frexp, ldexp, modf
@@ -83,9 +83,9 @@ STATIC const mp_map_elem_t mp_module_math_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_floor), (mp_obj_t)&mp_math_floor_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_fmod), (mp_obj_t)&mp_math_fmod_obj },
     //{ MP_OBJ_NEW_QSTR(MP_QSTR_frexp), (mp_obj_t)&mp_math_frexp_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_isfinite), (mp_obj_t)&mp_math_isfinite_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_isinf), (mp_obj_t)&mp_math_isinf_obj },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_isnan), (mp_obj_t)&mp_math_isnan_obj },
+    //{ MP_OBJ_NEW_QSTR(MP_QSTR_isfinite), (mp_obj_t)&mp_math_isfinite_obj },
+    //{ MP_OBJ_NEW_QSTR(MP_QSTR_isinf), (mp_obj_t)&mp_math_isinf_obj },
+    //{ MP_OBJ_NEW_QSTR(MP_QSTR_isnan), (mp_obj_t)&mp_math_isnan_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_trunc), (mp_obj_t)&mp_math_trunc_obj },
 };
 
diff --git a/py/objcomplex.c b/py/objcomplex.c
index 65957cbf60..2ba5226150 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -6,6 +6,7 @@
 #include "mpconfig.h"
 #include "qstr.h"
 #include "obj.h"
+#include "parsenum.h"
 #include "runtime0.h"
 #include "map.h"
 
@@ -36,15 +37,20 @@ STATIC mp_obj_t complex_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const
             return mp_obj_new_complex(0, 0);
 
         case 1:
-            // TODO allow string as first arg and parse it
-            if (MP_OBJ_IS_TYPE(args[0], &mp_type_complex)) {
+            if (MP_OBJ_IS_STR(args[0])) {
+                // a string, parse it
+                uint l;
+                const char *s = mp_obj_str_get_data(args[0], &l);
+                return mp_parse_num_decimal(s, l, true, true);
+            } else if (MP_OBJ_IS_TYPE(args[0], &mp_type_complex)) {
+                // a complex, just return it
                 return args[0];
             } else {
+                // something else, try to cast it to a complex
                 return mp_obj_new_complex(mp_obj_get_float(args[0]), 0);
             }
 
-        case 2:
-        {
+        case 2: {
             mp_float_t real, imag;
             if (MP_OBJ_IS_TYPE(args[0], &mp_type_complex)) {
                 mp_obj_complex_get(args[0], &real, &imag);
diff --git a/py/objfloat.c b/py/objfloat.c
index 704b3d5998..c4567c4a38 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -39,10 +39,12 @@ STATIC mp_obj_t float_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const m
                 // a string, parse it
                 uint l;
                 const char *s = mp_obj_str_get_data(args[0], &l);
-                return mp_parse_num_decimal(s, l);
+                return mp_parse_num_decimal(s, l, false, false);
             } else if (MP_OBJ_IS_TYPE(args[0], &mp_type_float)) {
+                // a float, just return it
                 return args[0];
             } else {
+                // something else, try to cast it to a float
                 return mp_obj_new_float(mp_obj_get_float(args[0]));
             }
 
diff --git a/py/objstr.c b/py/objstr.c
index d660bf952b..35a948700c 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -14,9 +14,11 @@ typedef struct _mp_obj_str_t {
     mp_obj_base_t base;
     machine_uint_t hash : 16; // XXX here we assume the hash size is 16 bits (it is at the moment; see qstr.c)
     machine_uint_t len : 16; // len == number of bytes used in data, alloc = len + 1 because (at the moment) we also append a null byte
-    byte data[];
+    const byte *data;
 } mp_obj_str_t;
 
+const mp_obj_t mp_const_empty_bytes;
+
 // use this macro to extract the string hash
 #define GET_STR_HASH(str_obj_in, str_hash) uint str_hash; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_hash = qstr_hash(MP_OBJ_QSTR_VALUE(str_obj_in)); } else { str_hash = ((mp_obj_str_t*)str_obj_in)->hash; }
 
@@ -28,6 +30,7 @@ typedef struct _mp_obj_str_t {
 
 STATIC mp_obj_t mp_obj_new_str_iterator(mp_obj_t str);
 STATIC mp_obj_t mp_obj_new_bytes_iterator(mp_obj_t str);
+STATIC mp_obj_t str_new(const mp_obj_type_t *type, const byte* data, uint len);
 
 /******************************************************************************/
 /* str                                                                        */
@@ -78,6 +81,109 @@ STATIC void str_print(void (*print)(void *env, const char *fmt, ...), void *env,
     }
 }
 
+STATIC mp_obj_t str_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
+    switch (n_args) {
+        case 0:
+            return MP_OBJ_NEW_QSTR(MP_QSTR_);
+
+        case 1:
+        {
+            vstr_t *vstr = vstr_new();
+            mp_obj_print_helper((void (*)(void*, const char*, ...))vstr_printf, vstr, args[0], PRINT_STR);
+            mp_obj_t s = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
+            vstr_free(vstr);
+            return s;
+        }
+
+        case 2:
+        case 3:
+        {
+            // TODO: validate 2nd/3rd args
+            if (!MP_OBJ_IS_TYPE(args[0], &bytes_type)) {
+                nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "bytes expected"));
+            }
+            GET_STR_DATA_LEN(args[0], str_data, str_len);
+            GET_STR_HASH(args[0], str_hash);
+            mp_obj_str_t *o = str_new(&str_type, NULL, str_len);
+            o->data = str_data;
+            o->hash = str_hash;
+            return o;
+        }
+
+        default:
+            nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "str takes at most 3 arguments"));
+    }
+}
+
+STATIC mp_obj_t bytes_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
+    if (n_args == 0) {
+        return mp_const_empty_bytes;
+    }
+
+    if (MP_OBJ_IS_STR(args[0])) {
+        if (n_args < 2 || n_args > 3) {
+            goto wrong_args;
+        }
+        GET_STR_DATA_LEN(args[0], str_data, str_len);
+        GET_STR_HASH(args[0], str_hash);
+        mp_obj_str_t *o = str_new(&bytes_type, NULL, str_len);
+        o->data = str_data;
+        o->hash = str_hash;
+        return o;
+    }
+
+    if (n_args > 1) {
+        goto wrong_args;
+    }
+
+    if (MP_OBJ_IS_SMALL_INT(args[0])) {
+        uint len = MP_OBJ_SMALL_INT_VALUE(args[0]);
+        byte *data;
+
+        mp_obj_t o = mp_obj_str_builder_start(&bytes_type, len, &data);
+        memset(data, 0, len);
+        return mp_obj_str_builder_end(o);
+    }
+
+    int len;
+    byte *data;
+    vstr_t *vstr = NULL;
+    mp_obj_t o = NULL;
+    // Try to create array of exact len if initializer len is known
+    mp_obj_t len_in = mp_obj_len_maybe(args[0]);
+    if (len_in == MP_OBJ_NULL) {
+        len = -1;
+        vstr = vstr_new();
+    } else {
+        len = MP_OBJ_SMALL_INT_VALUE(len_in);
+        o = mp_obj_str_builder_start(&bytes_type, len, &data);
+    }
+
+    mp_obj_t iterable = rt_getiter(args[0]);
+    mp_obj_t item;
+    while ((item = rt_iternext(iterable)) != mp_const_stop_iteration) {
+        if (len == -1) {
+            vstr_add_char(vstr, MP_OBJ_SMALL_INT_VALUE(item));
+        } else {
+            *data++ = MP_OBJ_SMALL_INT_VALUE(item);
+        }
+    }
+
+    if (len == -1) {
+        vstr_shrink(vstr);
+        // TODO: Optimize, borrow buffer from vstr
+        len = vstr_len(vstr);
+        o = mp_obj_str_builder_start(&bytes_type, len, &data);
+        memcpy(data, vstr_str(vstr), len);
+        vstr_free(vstr);
+    }
+
+    return mp_obj_str_builder_end(o);
+
+wrong_args:
+        nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError, "wrong number of arguments"));
+}
+
 // like strstr but with specified length and allows \0 bytes
 // TODO replace with something more efficient/standard
 STATIC const byte *find_subbytes(const byte *haystack, uint hlen, const byte *needle, uint nlen) {
@@ -520,6 +626,62 @@ STATIC mp_obj_t str_count(uint n_args, const mp_obj_t *args) {
     return MP_OBJ_NEW_SMALL_INT(num_occurrences);
 }
 
+STATIC mp_obj_t str_partitioner(mp_obj_t self_in, mp_obj_t arg, machine_int_t direction) {
+    assert(MP_OBJ_IS_STR(self_in));
+    if (!MP_OBJ_IS_STR(arg)) {
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
+                                               "Can't convert '%s' object to str implicitly", mp_obj_get_type_str(arg)));
+    }
+
+    GET_STR_DATA_LEN(self_in, str, str_len);
+    GET_STR_DATA_LEN(arg, sep, sep_len);
+
+    if (sep_len == 0) {
+        nlr_jump(mp_obj_new_exception_msg(&mp_type_ValueError, "empty separator"));
+    }
+
+    mp_obj_t result[] = {MP_OBJ_NEW_QSTR(MP_QSTR_), MP_OBJ_NEW_QSTR(MP_QSTR_), MP_OBJ_NEW_QSTR(MP_QSTR_)};
+
+    if (direction > 0) {
+        result[0] = self_in;
+    } else {
+        result[2] = self_in;
+    }
+
+    if (str_len >= sep_len) {
+        machine_uint_t str_index, str_index_end;
+        if (direction > 0) {
+            str_index = 0;
+            str_index_end = str_len - sep_len;
+        } else {
+            str_index = str_len - sep_len;
+            str_index_end = 0;
+        }
+        for (;;) {
+            if (memcmp(&str[str_index], sep, sep_len) == 0) {
+                result[0] = mp_obj_new_str(str, str_index, false);
+                result[1] = arg;
+                result[2] = mp_obj_new_str(str + str_index + sep_len, str_len - str_index - sep_len, false);
+                break;
+            }
+            if (str_index == str_index_end) {
+                break;
+            }
+            str_index += direction;
+        }
+    }
+
+    return mp_obj_new_tuple(3, result);
+}
+
+STATIC mp_obj_t str_partition(mp_obj_t self_in, mp_obj_t arg) {
+    return str_partitioner(self_in, arg, 1);
+}
+
+STATIC mp_obj_t str_rpartition(mp_obj_t self_in, mp_obj_t arg) {
+    return str_partitioner(self_in, arg, -1);
+}
+
 STATIC machine_int_t str_get_buffer(mp_obj_t self_in, buffer_info_t *bufinfo, int flags) {
     if (flags == BUFFER_READ) {
         GET_STR_DATA_LEN(self_in, str_data, str_len);
@@ -542,6 +704,8 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_strip_obj, 1, 2, str_strip);
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR(str_format_obj, 1, str_format);
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_replace_obj, 3, 4, str_replace);
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_count_obj, 2, 4, str_count);
+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 const mp_method_t str_type_methods[] = {
     { "find", &str_find_obj },
@@ -552,6 +716,8 @@ STATIC const mp_method_t str_type_methods[] = {
     { "format", &str_format_obj },
     { "replace", &str_replace_obj },
     { "count", &str_count_obj },
+    { "partition", &str_partition_obj },
+    { "rpartition", &str_rpartition_obj },
     { NULL, NULL }, // end-of-list sentinel
 };
 
@@ -559,6 +725,7 @@ const mp_obj_type_t str_type = {
     { &mp_type_type },
     .name = MP_QSTR_str,
     .print = str_print,
+    .make_new = str_make_new,
     .binary_op = str_binary_op,
     .getiter = mp_obj_new_str_iterator,
     .methods = str_type_methods,
@@ -570,34 +737,45 @@ const mp_obj_type_t bytes_type = {
     { &mp_type_type },
     .name = MP_QSTR_bytes,
     .print = str_print,
+    .make_new = bytes_make_new,
     .binary_op = str_binary_op,
     .getiter = mp_obj_new_bytes_iterator,
     .methods = str_type_methods,
 };
 
+// the zero-length bytes
+STATIC const mp_obj_str_t empty_bytes_obj = {{&bytes_type}, 0, 0, NULL};
+const mp_obj_t mp_const_empty_bytes = (mp_obj_t)&empty_bytes_obj;
+
 mp_obj_t mp_obj_str_builder_start(const mp_obj_type_t *type, uint len, byte **data) {
-    mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
+    mp_obj_str_t *o = m_new_obj(mp_obj_str_t);
     o->base.type = type;
     o->len = len;
-    *data = o->data;
+    byte *p = m_new(byte, len + 1);
+    o->data = p;
+    *data = p;
     return o;
 }
 
 mp_obj_t mp_obj_str_builder_end(mp_obj_t o_in) {
-    assert(MP_OBJ_IS_STR(o_in));
     mp_obj_str_t *o = o_in;
     o->hash = qstr_compute_hash(o->data, o->len);
-    o->data[o->len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
+    byte *p = (byte*)o->data;
+    p[o->len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
     return o;
 }
 
 STATIC mp_obj_t str_new(const mp_obj_type_t *type, const byte* data, uint len) {
-    mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
+    mp_obj_str_t *o = m_new_obj(mp_obj_str_t);
     o->base.type = type;
-    o->hash = qstr_compute_hash(data, len);
     o->len = len;
-    memcpy(o->data, data, len * sizeof(byte));
-    o->data[len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
+    if (data) {
+        o->hash = qstr_compute_hash(data, len);
+        byte *p = m_new(byte, len + 1);
+        o->data = p;
+        memcpy(p, data, len * sizeof(byte));
+        p[len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
+    }
     return o;
 }
 
diff --git a/py/parsenum.c b/py/parsenum.c
index c9cef5fcd8..7be53897a7 100644
--- a/py/parsenum.c
+++ b/py/parsenum.c
@@ -9,139 +9,217 @@
 #include "parsenumbase.h"
 #include "parsenum.h"
 
-#if defined(UNIX)
-
-#include <ctype.h>
-#include <errno.h>
+#if MICROPY_ENABLE_FLOAT
+#include <math.h>
+#endif
 
 mp_obj_t mp_parse_num_integer(const char *restrict str, uint len, int base) {
-    // TODO at the moment we ignore len; we should honour it!
-    // TODO detect integer overflow and return bignum
-
-    int c, neg = 0;
-    const char *p = str;
-    char *num;
-    long found;
+    const char *restrict top = str + len;
+    bool neg = false;
 
     // check radix base
     if ((base != 0 && base < 2) || base > 36) {
         nlr_jump(mp_obj_new_exception_msg(&mp_type_ValueError, "ValueError: int() arg 2 must be >=2 and <= 36"));
     }
-    // skip surrounded whitespace
-    while (isspace((c = *(p++))));
-    if (c == 0) {
-        goto value_error;
+
+    // skip leading space
+    for (; str < top && unichar_isspace(*str); str++) {
     }
-    // preced sign
-    if (c == '+' || c == '-') {
-        neg = - (c == '-');
-    } else {
-        p--;
+
+    // parse optional sign
+    if (str < top) {
+        if (*str == '+') {
+            str++;
+        } else if (*str == '-') {
+            str++;
+            neg = true;
+        }
     }
 
-    len -= p - str;
-    int skip = mp_parse_num_base(p, len, &base);
-    p += skip;
-    len -= skip;
+    // parse optional base prefix
+    str += mp_parse_num_base(str, top - str, &base);
 
-    errno = 0;
-    found = strtol(p, &num, base);
-    if (errno) {
-        goto value_error;
-    } else if (found && *(num) == 0) {
-        goto done;
-    } else if (found || num != p) {
-        goto check_tail_space;
-    } else {
+    // string should be an integer number
+    machine_int_t int_val = 0;
+    const char *restrict str_val_start = str;
+    for (; str < top; str++) {
+        machine_int_t old_val = int_val;
+        int dig = *str;
+        if (unichar_isdigit(dig) && dig - '0' < base) {
+            // 0-9 digit
+            int_val = base * int_val + dig - '0';
+        } else if (base == 16) {
+            dig |= 0x20;
+            if ('a' <= dig && dig <= 'f') {
+                // a-f hex digit
+                int_val = base * int_val + dig - 'a' + 10;
+            } else {
+                // unknown character
+                break;
+            }
+        } else {
+            // unknown character
+            break;
+        }
+        if (int_val < old_val) {
+            // If new value became less than previous, it's overflow
+            goto overflow;
+        } else if ((old_val ^ int_val) & WORD_MSBIT_HIGH) {
+            // If signed number changed sign - it's overflow
+            goto overflow;
+        }
+    }
+
+    // check we parsed something
+    if (str == str_val_start) {
         goto value_error;
     }
 
-check_tail_space:
-    if (*(num) != 0) {
-        while (isspace((c = *(num++))));
-        if (c != 0) {
-            goto value_error;
-        }
+    // negate value if needed
+    if (neg) {
+        int_val = -int_val;
+    }
+
+    // skip trailing space
+    for (; str < top && unichar_isspace(*str); str++) {
+    }
+
+    // check we reached the end of the string
+    if (str != top) {
+        goto value_error;
     }
 
-done:
-    return MP_OBJ_NEW_SMALL_INT((found ^ neg) - neg);
+    // return the object
+    return MP_OBJ_NEW_SMALL_INT(int_val);
 
 value_error:
     nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid literal for int() with base %d: '%s'", base, str));
-}
 
-#else /* defined(UNIX) */
-
-mp_obj_t mp_parse_num_integer(const char *restrict str, uint len, int base) {
-    // TODO port strtol to stm
-    return MP_OBJ_NEW_SMALL_INT(0);
+overflow:
+    // TODO reparse using bignum
+    nlr_jump(mp_obj_new_exception_msg(&mp_type_ValueError, "overflow parsing integer"));
 }
 
-#endif /* defined(UNIX) */
-
 #define PARSE_DEC_IN_INTG (1)
 #define PARSE_DEC_IN_FRAC (2)
 #define PARSE_DEC_IN_EXP  (3)
 
-mp_obj_t mp_parse_num_decimal(const char *str, uint len) {
+mp_obj_t mp_parse_num_decimal(const char *str, uint len, bool allow_imag, bool force_complex) {
 #if MICROPY_ENABLE_FLOAT
-    int in = PARSE_DEC_IN_INTG;
+    const char *top = str + len;
     mp_float_t dec_val = 0;
-    bool exp_neg = false;
-    int exp_val = 0;
-    int exp_extra = 0;
+    bool dec_neg = false;
     bool imag = false;
-    const char *top = str + len;
-    for (; str < top; str++) {
-        int dig = *str;
-        if ('0' <= dig && dig <= '9') {
-            dig -= '0';
-            if (in == PARSE_DEC_IN_EXP) {
-                exp_val = 10 * exp_val + dig;
-            } else {
-                dec_val = 10 * dec_val + dig;
-                if (in == PARSE_DEC_IN_FRAC) {
-                    exp_extra -= 1;
-                }
+
+    // skip leading space
+    for (; str < top && unichar_isspace(*str); str++) {
+    }
+
+    // parse optional sign
+    if (str < top) {
+        if (*str == '+') {
+            str++;
+        } else if (*str == '-') {
+            str++;
+            dec_neg = true;
+        }
+    }
+
+    // determine what the string is
+    if (str < top && (str[0] | 0x20) == 'i') {
+        // string starts with 'i', should be 'inf' or 'infinity' (case insensitive)
+        if (str + 2 < top && (str[1] | 0x20) == 'n' && (str[2] | 0x20) == 'f') {
+            // inf
+            str += 3;
+            dec_val = INFINITY;
+            if (str + 4 < top && (str[0] | 0x20) == 'i' && (str[1] | 0x20) == 'n' && (str[2] | 0x20) == 'i' && (str[3] | 0x20) == 't' && (str[4] | 0x20) == 'y') {
+                // infinity
+                str += 5;
             }
-        } else if (in == PARSE_DEC_IN_INTG && dig == '.') {
-            in = PARSE_DEC_IN_FRAC;
-        } else if (in != PARSE_DEC_IN_EXP && (dig == 'E' || dig == 'e')) {
-            in = PARSE_DEC_IN_EXP;
-            if (str[1] == '+') {
-                str++;
-            } else if (str[1] == '-') {
+        }
+    } else if (str < top && (str[0] | 0x20) == 'n') {
+        // string starts with 'n', should be 'nan' (case insensitive)
+        if (str + 2 < top && (str[1] | 0x20) == 'a' && (str[2] | 0x20) == 'n') {
+            // NaN
+            str += 3;
+            dec_val = MICROPY_FLOAT_C_FUN(nan)("");
+        }
+    } else {
+        // string should be a decimal number
+        int in = PARSE_DEC_IN_INTG;
+        bool exp_neg = false;
+        int exp_val = 0;
+        int exp_extra = 0;
+        for (; str < top; str++) {
+            int dig = *str;
+            if ('0' <= dig && dig <= '9') {
+                dig -= '0';
+                if (in == PARSE_DEC_IN_EXP) {
+                    exp_val = 10 * exp_val + dig;
+                } else {
+                    dec_val = 10 * dec_val + dig;
+                    if (in == PARSE_DEC_IN_FRAC) {
+                        exp_extra -= 1;
+                    }
+                }
+            } else if (in == PARSE_DEC_IN_INTG && dig == '.') {
+                in = PARSE_DEC_IN_FRAC;
+            } else if (in != PARSE_DEC_IN_EXP && ((dig | 0x20) == 'e')) {
+                in = PARSE_DEC_IN_EXP;
+                if (str[1] == '+') {
+                    str++;
+                } else if (str[1] == '-') {
+                    str++;
+                    exp_neg = true;
+                }
+            } else if (allow_imag && (dig | 0x20) == 'j') {
                 str++;
-                exp_neg = true;
+                imag = true;
+                break;
+            } else {
+                // unknown character
+                break;
             }
-        } else if (dig == 'J' || dig == 'j') {
-            str++;
-            imag = true;
-            break;
-        } else {
-            // unknown character
-            break;
+        }
+
+        // work out the exponent
+        if (exp_neg) {
+            exp_val = -exp_val;
+        }
+        exp_val += exp_extra;
+
+        // apply the exponent
+        for (; exp_val > 0; exp_val--) {
+            dec_val *= 10;
+        }
+        for (; exp_val < 0; exp_val++) {
+            dec_val *= 0.1;
         }
     }
-    if (*str != 0) {
-        nlr_jump(mp_obj_new_exception_msg(&mp_type_SyntaxError, "invalid syntax for number"));
-    }
-    if (exp_neg) {
-        exp_val = -exp_val;
+
+    // negate value if needed
+    if (dec_neg) {
+        dec_val = -dec_val;
     }
-    exp_val += exp_extra;
-    for (; exp_val > 0; exp_val--) {
-        dec_val *= 10;
+
+    // skip trailing space
+    for (; str < top && unichar_isspace(*str); str++) {
     }
-    for (; exp_val < 0; exp_val++) {
-        dec_val *= 0.1;
+
+    // check we reached the end of the string
+    if (str != top) {
+        nlr_jump(mp_obj_new_exception_msg(&mp_type_SyntaxError, "invalid syntax for number"));
     }
+
+    // return the object
     if (imag) {
         return mp_obj_new_complex(0, dec_val);
+    } else if (force_complex) {
+        return mp_obj_new_complex(dec_val, 0);
     } else {
         return mp_obj_new_float(dec_val);
     }
+
 #else
     nlr_jump(mp_obj_new_exception_msg(&mp_type_SyntaxError, "decimal numbers not supported"));
 #endif
diff --git a/py/parsenum.h b/py/parsenum.h
index 5a2e42da50..97578423c7 100644
--- a/py/parsenum.h
+++ b/py/parsenum.h
@@ -1,2 +1,2 @@
 mp_obj_t mp_parse_num_integer(const char *restrict str, uint len, int base);
-mp_obj_t mp_parse_num_decimal(const char *str, uint len);
+mp_obj_t mp_parse_num_decimal(const char *str, uint len, bool allow_imag, bool force_complex);
diff --git a/py/runtime.c b/py/runtime.c
index b57a74fa38..68edf54567 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -89,6 +89,7 @@ STATIC const mp_builtin_elem_t builtin_table[] = {
 
     // built-in types
     { MP_QSTR_bool, (mp_obj_t)&bool_type },
+    { MP_QSTR_bytes, (mp_obj_t)&bytes_type },
 #if MICROPY_ENABLE_FLOAT
     { MP_QSTR_complex, (mp_obj_t)&mp_type_complex },
 #endif
@@ -102,6 +103,7 @@ STATIC const mp_builtin_elem_t builtin_table[] = {
     { MP_QSTR_list, (mp_obj_t)&list_type },
     { MP_QSTR_map, (mp_obj_t)&map_type },
     { MP_QSTR_set, (mp_obj_t)&set_type },
+    { MP_QSTR_str, (mp_obj_t)&str_type },
     { MP_QSTR_super, (mp_obj_t)&super_type },
     { MP_QSTR_tuple, (mp_obj_t)&tuple_type },
     { MP_QSTR_type, (mp_obj_t)&mp_type_type },
@@ -114,7 +116,6 @@ STATIC const mp_builtin_elem_t builtin_table[] = {
     { MP_QSTR_abs, (mp_obj_t)&mp_builtin_abs_obj },
     { MP_QSTR_all, (mp_obj_t)&mp_builtin_all_obj },
     { MP_QSTR_any, (mp_obj_t)&mp_builtin_any_obj },
-    { MP_QSTR_bytes, (mp_obj_t)&mp_builtin_bytes_obj },
     { MP_QSTR_callable, (mp_obj_t)&mp_builtin_callable_obj },
     { MP_QSTR_chr, (mp_obj_t)&mp_builtin_chr_obj },
     { MP_QSTR_dir, (mp_obj_t)&mp_builtin_dir_obj },
@@ -137,7 +138,6 @@ STATIC const mp_builtin_elem_t builtin_table[] = {
     { MP_QSTR_repr, (mp_obj_t)&mp_builtin_repr_obj },
     { MP_QSTR_sorted, (mp_obj_t)&mp_builtin_sorted_obj },
     { MP_QSTR_sum, (mp_obj_t)&mp_builtin_sum_obj },
-    { MP_QSTR_str, (mp_obj_t)&mp_builtin_str_obj },
     { MP_QSTR_bytearray, (mp_obj_t)&mp_builtin_bytearray_obj },
 
     // built-in exceptions
@@ -376,7 +376,7 @@ mp_obj_t rt_load_const_dec(qstr qstr) {
     DEBUG_OP_printf("load '%s'\n", qstr_str(qstr));
     uint len;
     const byte* data = qstr_data(qstr, &len);
-    return mp_parse_num_decimal((const char*)data, len);
+    return mp_parse_num_decimal((const char*)data, len, true, false);
 }
 
 mp_obj_t rt_load_const_str(qstr qstr) {
diff --git a/py/showbc.c b/py/showbc.c
index bc81086c7d..9bdf811d9a 100644
--- a/py/showbc.c
+++ b/py/showbc.c
@@ -394,6 +394,10 @@ void mp_byte_code_print(const byte *ip, int len) {
                 printf("YIELD_VALUE");
                 break;
 
+            case MP_BC_YIELD_FROM:
+                printf("YIELD_FROM");
+                break;
+
             case MP_BC_IMPORT_NAME:
                 DECODE_QSTR;
                 printf("IMPORT_NAME %s", qstr_str(qstr));