Add string formatting support for longlong and mpz.

py/mpz.c

@@ -1216,15 +1216,27 @@ uint mpz_as_str_size(const mpz_t *i, uint base) {
     return i->len * DIG_SIZE / log_base2_floor[base] + 2 + 1; // +1 for null byte termination
 }
 
+uint mpz_as_str_size_formatted(const mpz_t *i, uint base, const char *prefix, char comma) {
+    if (base < 2 || base > 32) {
+        return 0;
+    }
+
+    uint num_digits = i->len * DIG_SIZE / log_base2_floor[base] + 1;
+    uint num_commas = comma ? num_digits / 3: 0;
+    uint prefix_len = prefix ? strlen(prefix) : 0;
+
+    return num_digits + num_commas + prefix_len + 2; // +1 for sign, +1 for null byte
+}
+
 char *mpz_as_str(const mpz_t *i, uint base) {
     char *s = m_new(char, mpz_as_str_size(i, base));
-    mpz_as_str_inpl(i, base, s);
+    mpz_as_str_inpl(i, base, "", 'a', 0, s);
     return s;
 }
 
 // assumes enough space as calculated by mpz_as_str_size
 // returns length of string, not including null byte
-uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
+uint mpz_as_str_inpl(const mpz_t *i, uint base, const char *prefix, char base_char, char comma, char *str) {
     if (str == NULL || base < 2 || base > 32) {
         str[0] = 0;
         return 0;
@@ -1232,10 +1244,15 @@ uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
 
     uint ilen = i->len;
 
+    char *s = str;
     if (ilen == 0) {
-        str[0] = '0';
-        str[1] = 0;
-        return 1;
+        if (prefix) {
+            while (*prefix)
+                *s++ = *prefix++;
+        }
+        *s++ = '0';
+        *s = '\0';
+        return s - str;
     }
 
     // make a copy of mpz digits
@@ -1243,7 +1260,7 @@ uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
     memcpy(dig, i->dig, ilen * sizeof(mpz_dig_t));
 
     // convert
-    char *s = str;
+    char *last_comma = str;
     bool done;
     do {
         mpz_dig_t *d = dig + ilen;
@@ -1259,7 +1276,7 @@ uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
         // convert to character
         a += '0';
         if (a > '9') {
-            a += 'a' - '9' - 1;
+            a += base_char - '9' - 1;
         }
         *s++ = a;
 
@@ -1271,8 +1288,19 @@ uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
                 break;
             }
         }
-    } while (!done);
+        if (comma && (s - last_comma) == 3) {
+            *s++ = comma;
+            last_comma = s;
+        }
+    }
+    while (!done);
 
+    if (prefix) {
+        const char *p = &prefix[strlen(prefix)];
+        while (p > prefix) {
+            *s++ = *--p;
+        }
+    }
     if (i->neg != 0) {
         *s++ = '-';
     }
@@ -1284,7 +1312,7 @@ uint mpz_as_str_inpl(const mpz_t *i, uint base, char *str) {
         *v = temp;
     }
 
-    s[0] = 0; // null termination
+    *s = '\0'; // null termination
 
     return s - str;
 }

py/mpz.h

@@ -76,5 +76,6 @@ bool mpz_as_int_checked(const mpz_t *z, machine_int_t *value);
 mp_float_t mpz_as_float(const mpz_t *z);
 #endif
 uint mpz_as_str_size(const mpz_t *z, uint base);
+uint mpz_as_str_size_formatted(const mpz_t *i, uint base, const char *prefix, char comma);
 char *mpz_as_str(const mpz_t *z, uint base);
-uint mpz_as_str_inpl(const mpz_t *z, uint base, char *str);
+uint mpz_as_str_inpl(const mpz_t *z, uint base, const char *prefix, char base_char, char comma, char *str);

py/objint.c

 #include <stdlib.h>
 #include <stdint.h>
 #include <assert.h>
+#include <string.h>
 
 #include "nlr.h"
 #include "misc.h"
@@ -53,14 +54,129 @@ STATIC mp_obj_t mp_obj_int_make_new(mp_obj_t type_in, uint n_args, uint n_kw, co
     }
 }
 
-#if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_NONE
-
 void mp_obj_int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
-    if (MP_OBJ_IS_SMALL_INT(self_in)) {
-        print(env, INT_FMT, MP_OBJ_SMALL_INT_VALUE(self_in));
+    // The size of this buffer is rather arbitrary. If it's not large
+    // enough, a dynamic one will be allocated.
+    char stack_buf[sizeof(machine_int_t) * 4];
+    char *buf = stack_buf;
+    int buf_size = sizeof(stack_buf);
+    int fmt_size;
+
+    char *str = mp_obj_int_formatted(&buf, &buf_size, &fmt_size, self_in, 10, NULL, '\0', '\0');
+    print(env, "%s", str);
+
+    if (buf != stack_buf) {
+        m_free(buf, buf_size);
+    }
+}
+
+#if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_NONE || MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_LONGLONG
+
+#if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_LONGLONG
+typedef mp_longint_impl_t   fmt_int_t;
+#else
+typedef mp_small_int_t   fmt_int_t;
+#endif
+
+static const uint log_base2_floor[] = {
+    0,
+    0, 1, 1, 2,
+    2, 2, 2, 3,
+    3, 3, 3, 3,
+    3, 3, 3, 4,
+    4, 4, 4, 4,
+    4, 4, 4, 4,
+    4, 4, 4, 4,
+    4, 4, 4, 5
+};
+
+uint int_as_str_size_formatted(uint base, const char *prefix, char comma) {
+    if (base < 2 || base > 32) {
+        return 0;
     }
+
+    uint num_digits = sizeof(fmt_int_t) * 8 / log_base2_floor[base] + 1;
+    uint num_commas = comma ? num_digits / 3: 0;
+    uint prefix_len = prefix ? strlen(prefix) : 0;
+    return num_digits + num_commas + prefix_len + 2; // +1 for sign, +1 for null byte
 }
 
+// This routine expects you to pass in a buffer and size (in *buf and buf_size).
+// If, for some reason, this buffer is too small, then it will allocate a
+// buffer and return the allocated buffer and size in *buf and *buf_size. It
+// is the callers responsibility to free this allocated buffer.
+//
+// The resulting formatted string will be returned from this function and the
+// formatted size will be in *fmt_size.
+char *mp_obj_int_formatted(char **buf, int *buf_size, int *fmt_size, mp_obj_t self_in,
+                           int base, const char *prefix, char base_char, char comma) {
+    if (!MP_OBJ_IS_INT(self_in)) {
+        buf[0] = '\0';
+        *fmt_size = 0;
+        return *buf;
+    }
+    fmt_int_t num = mp_obj_get_int(self_in);
+    char sign = '\0';
+    if (num < 0) {
+        num = -num;
+        sign = '-';
+    }
+
+    uint needed_size = int_as_str_size_formatted(base, prefix, comma);
+    if (needed_size > *buf_size) {
+        *buf = m_new(char, needed_size);
+        *buf_size = needed_size;
+    }
+    char *str = *buf;
+
+    char *b = str + needed_size;
+    *(--b) = '\0';
+    char *last_comma = b;
+
+    if (num == 0) {
+        *(--b) = '0';
+    } else {
+        do {
+            int c = num % base;
+            num /= base;
+            if (c >= 10) {
+                c += base_char - 10;
+            } else {
+                c += '0';
+            }
+            *(--b) = c;
+            if (comma && num != 0 && b > str && (last_comma - b) == 3) {
+                *(--b) = comma;
+                last_comma = b;
+            }
+        }
+        while (b > str && num != 0);
+    }
+    if (prefix) {
+        size_t prefix_len = strlen(prefix);
+        char *p = b - prefix_len;
+        if (p > str) {
+            b = p;
+            while (*prefix) {
+                *p++ = *prefix++;
+            }
+        }
+    }
+    if (sign && b > str) {
+        *(--b) = sign;
+    }
+    *fmt_size = *buf + needed_size - b - 1;
+
+    return b;
+}
+
+bool mp_obj_int_is_positive(mp_obj_t self_in) {
+    return mp_obj_get_int(self_in) >= 0;
+}
+#endif  // LONGLONG or NONE
+
+#if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_NONE
+
 // This is called for operations on SMALL_INT that are not handled by mp_unary_op
 mp_obj_t mp_obj_int_unary_op(int op, mp_obj_t o_in) {
     return MP_OBJ_NULL;

py/objint.h

@@ -8,6 +8,9 @@ typedef struct _mp_obj_int_t {
 } mp_obj_int_t;
 
 void mp_obj_int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind);
+char *mp_obj_int_formatted(char **buf, int *buf_size, int *fmt_size, mp_obj_t self_in,
+                           int base, const char *prefix, char base_char, char comma);
+bool mp_obj_int_is_positive(mp_obj_t self_in);
 mp_obj_t mp_obj_int_unary_op(int op, mp_obj_t o_in);
 mp_obj_t mp_obj_int_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in);
 mp_obj_t mp_obj_int_binary_op_extra_cases(int op, mp_obj_t lhs_in, mp_obj_t rhs_in);

py/objint_longlong.c

 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "nlr.h"
 #include "misc.h"
@@ -21,15 +22,6 @@
 #define SUFFIX ""
 #endif
 
-void mp_obj_int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
-    if (MP_OBJ_IS_SMALL_INT(self_in)) {
-        print(env, INT_FMT, MP_OBJ_SMALL_INT_VALUE(self_in));
-    } else {
-        mp_obj_int_t *self = self_in;
-        print(env, "%lld" SUFFIX, self->val);
-    }
-}
-
 mp_obj_t mp_obj_int_unary_op(int op, mp_obj_t o_in) {
     mp_obj_int_t *o = o_in;
     switch (op) {

py/objint_mpz.c

@@ -22,16 +22,47 @@ STATIC mp_obj_int_t *mp_obj_int_new_mpz(void) {
     return o;
 }
 
-void mp_obj_int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+// This routine expects you to pass in a buffer and size (in *buf and buf_size).
+// If, for some reason, this buffer is too small, then it will allocate a
+// buffer and return the allocated buffer and size in *buf and *buf_size. It
+// is the callers responsibility to free this allocated buffer.
+//
+// The resulting formatted string will be returned from this function and the
+// formatted size will be in *fmt_size.
+char *mp_obj_int_formatted(char **buf, int *buf_size, int *fmt_size, mp_obj_t self_in,
+                           int base, const char *prefix, char base_char, char comma) {
+    mpz_t small_mpz;
+    mpz_t *mpz;
+    mpz_dig_t small_dig[(sizeof(mp_small_int_t) * 8 + MPZ_DIG_SIZE - 1) / MPZ_DIG_SIZE];
+
     if (MP_OBJ_IS_SMALL_INT(self_in)) {
-        print(env, INT_FMT, MP_OBJ_SMALL_INT_VALUE(self_in));
+        mpz_init_fixed_from_int(&small_mpz, small_dig,
+                                sizeof(small_dig) / sizeof(small_dig[0]),
+                                MP_OBJ_SMALL_INT_VALUE(self_in));
+        mpz = &small_mpz;
     } else {
-        // TODO would rather not allocate memory to print...
         mp_obj_int_t *self = self_in;
-        char *str = mpz_as_str(&self->mpz, 10);
-        print(env, "%s", str);
-        m_free(str, 0);
+        mpz = &self->mpz;
+    }
+
+    uint needed_size = mpz_as_str_size_formatted(mpz, base, prefix, comma);
+    if (needed_size > *buf_size) {
+        *buf = m_new(char, needed_size);
+        *buf_size = needed_size;
+    }
+    char *str = *buf;
+
+    *fmt_size = mpz_as_str_inpl(mpz, base, prefix, base_char, comma, str);
+
+    return str;
+}
+
+bool mp_obj_int_is_positive(mp_obj_t self_in) {
+    if (MP_OBJ_IS_SMALL_INT(self_in)) {
+        return MP_OBJ_SMALL_INT_VALUE(self_in) >= 0;
     }
+    mp_obj_int_t *self = self_in;
+    return !self->mpz.neg;
 }
 
 mp_obj_t mp_obj_int_unary_op(int op, mp_obj_t o_in) {

py/objstr.c

@@ -562,13 +562,17 @@ static bool arg_looks_numeric(mp_obj_t arg) {
     ;
 }
 
-static machine_int_t arg_as_int(mp_obj_t arg) {
+static mp_obj_t arg_as_int(mp_obj_t arg) {
 #if MICROPY_ENABLE_FLOAT
     if (MP_OBJ_IS_TYPE(arg, &mp_type_float)) {
-        return mp_obj_get_float(arg);
+
+        // TODO: Needs a way to construct an mpz integer from a float
+
+        mp_small_int_t num = mp_obj_get_float(arg);
+        return MP_OBJ_NEW_SMALL_INT(num);
     }
 #endif
-    return mp_obj_get_int(arg);
+    return arg;
 }
 
 mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
@@ -788,7 +792,7 @@ mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
         if (arg_looks_integer(arg)) {
             switch (type) {
                 case 'b':
-                    pfenv_print_int(&pfenv_vstr, mp_obj_get_int(arg), 1, 2, 'a', flags, fill, width);
+                    pfenv_print_int(&pfenv_vstr, arg, 1, 2, 'a', flags, fill, width);
                     continue;
 
                 case 'c':
@@ -801,19 +805,23 @@ mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
                 case '\0':  // No explicit format type implies 'd'
                 case 'n':   // I don't think we support locales in uPy so use 'd'
                 case 'd':
-                    pfenv_print_int(&pfenv_vstr, mp_obj_get_int(arg), 1, 10, 'a', flags, fill, width);
+                    pfenv_print_int(&pfenv_vstr, arg, 1, 10, 'a', flags, fill, width);
                     continue;
 
                 case 'o':
-                    pfenv_print_int(&pfenv_vstr, mp_obj_get_int(arg), 1, 8, 'a', flags, fill, width);
+                    if (flags & PF_FLAG_SHOW_PREFIX) {
+                        flags |= PF_FLAG_SHOW_OCTAL_LETTER;
+                    }
+
+                    pfenv_print_int(&pfenv_vstr, arg, 1, 8, 'a', flags, fill, width);
                     continue;
 
                 case 'x':
-                    pfenv_print_int(&pfenv_vstr, mp_obj_get_int(arg), 1, 16, 'a', flags, fill, width);
+                    pfenv_print_int(&pfenv_vstr, arg, 1, 16, 'a', flags, fill, width);
                     continue;
 
                 case 'X':
-                    pfenv_print_int(&pfenv_vstr, mp_obj_get_int(arg), 1, 16, 'A', flags, fill, width);
+                    pfenv_print_int(&pfenv_vstr, arg, 1, 16, 'A', flags, fill, width);
                     continue;
 
                 case 'e':
@@ -1050,7 +1058,7 @@ STATIC mp_obj_t str_modulo_format(mp_obj_t pattern, uint n_args, const mp_obj_t
 
             case 'o':
                 if (alt) {
-                    flags |= PF_FLAG_SHOW_PREFIX;
+                    flags |= (PF_FLAG_SHOW_PREFIX | PF_FLAG_SHOW_OCTAL_LETTER);
                 }
                 pfenv_print_int(&pfenv_vstr, arg_as_int(arg), 1, 8, 'a', flags, fill, width); 
                 break;

py/pfenv.c

@@ -5,6 +5,8 @@
 #include "mpconfig.h"
 #include "qstr.h"
 #include "obj.h"
+#include "mpz.h"
+#include "objint.h"
 #include "pfenv.h"
 
 #if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
@@ -79,71 +81,88 @@ int pfenv_print_strn(const pfenv_t *pfenv, const char *str, unsigned int len, in
 // We can use 16 characters for 32-bit and 32 characters for 64-bit
 #define INT_BUF_SIZE (sizeof(machine_int_t) * 4)
 
-int pfenv_print_int(const pfenv_t *pfenv, machine_uint_t x, int sgn, int base, int base_char, int flags, char fill, int width) {
-    char sign = 0;
-    if (sgn) {
-        if ((machine_int_t)x < 0) {
-            sign = '-';
-            x = -x;
-        } else if (flags & PF_FLAG_SHOW_SIGN) {
-            sign = '+';
-        } else if (flags & PF_FLAG_SPACE_SIGN) {
-            sign = ' ';
-        }
+int pfenv_print_int(const pfenv_t *pfenv, mp_obj_t x, int sgn, int base, int base_char, int flags, char fill, int width) {
+    if (!MP_OBJ_IS_INT(x)) {
+        // This will convert booleans to int, or raise an error for
+        // non-integer types.
+        x = MP_OBJ_NEW_SMALL_INT(mp_obj_get_int(x));
     }
 
-    char buf[INT_BUF_SIZE];
-    char *b = buf + INT_BUF_SIZE;
+    char prefix_buf[4];
+    char *prefix = prefix_buf;
 
-    if (x == 0) {
-        *(--b) = '0';
-    } else {
-        do {
-            int c = x % base;
-            x /= base;
-            if (c >= 10) {
-                c += base_char - 10;
-            } else {
-                c += '0';
-            }
-            *(--b) = c;
-        } while (b > buf && x != 0);
+    if (mp_obj_int_is_positive(x)) {
+        if (flags & PF_FLAG_SHOW_SIGN) {
+            *prefix++ = '+';
+        } else if (flags & PF_FLAG_SPACE_SIGN) {
+            *prefix++ = ' ';
+        }
     }
 
-    char prefix_char = '\0';
-
     if (flags & PF_FLAG_SHOW_PREFIX) {
         if (base == 2) {
-            prefix_char = base_char + 'b' - 'a';
+            *prefix++ = '0';
+            *prefix++ = base_char + 'b' - 'a';
         } else if (base == 8) {
-            prefix_char = base_char + 'o' - 'a';
+            *prefix++ = '0';
+            if (flags & PF_FLAG_SHOW_OCTAL_LETTER) {
+                *prefix++ = base_char + 'o' - 'a';
+            }
         } else if (base == 16) {
-            prefix_char = base_char + 'x' - 'a';
+            *prefix++ = '0';
+            *prefix++ = base_char + 'x' - 'a';
+        }
+    }
+    *prefix = '\0';
+    int prefix_len = prefix - prefix_buf;
+    prefix = prefix_buf;
+
+    char comma = '\0';
+    if (flags & PF_FLAG_SHOW_COMMA) {
+        comma = ',';
+    }
+
+    // The size of this buffer is rather arbitrary. If it's not large
+    // enough, a dynamic one will be allocated.
+    char stack_buf[sizeof(machine_int_t) * 4];
+    char *buf = stack_buf;
+    int buf_size = sizeof(stack_buf);
+    int fmt_size = 0;
+    char *str;
+
+    char sign = '\0';
+    if (flags & PF_FLAG_PAD_AFTER_SIGN) {
+        // We add the pad in this function, so since the pad goes after
+        // the sign & prefix, we format without a prefix
+        str = mp_obj_int_formatted(&buf, &buf_size, &fmt_size,
+                                   x, base, NULL, base_char, comma);
+        if (*str == '-') {
+            sign = *str++;
+            fmt_size--;
         }
+    } else {
+        str = mp_obj_int_formatted(&buf, &buf_size, &fmt_size,
+                                   x, base, prefix, base_char, comma);
     }
 
     int len = 0;
     if (flags & PF_FLAG_PAD_AFTER_SIGN) {
+        // pad after sign implies pad after prefix as well.
         if (sign) {
-            len += pfenv_print_strn(pfenv, &sign, 1, flags, fill, 1);
+            len += pfenv_print_strn(pfenv, &sign, 1, 0, 0, 1);
             width--;
         }
-        if (prefix_char) {
-            len += pfenv_print_strn(pfenv, "0", 1, flags, fill, 1);
-            len += pfenv_print_strn(pfenv, &prefix_char, 1, flags, fill, 1);
-            width -= 2;
-        }
-    } else {
-        if (prefix_char && b > &buf[1]) {
-            *(--b) = prefix_char;
-            *(--b) = '0';
-        }
-        if (sign && b > buf) {
-            *(--b) = sign;
+        if (prefix_len) {
+            len += pfenv_print_strn(pfenv, prefix, prefix_len, 0, 0, 1);
+            width -= prefix_len;
         }
     }
 
-    len += pfenv_print_strn(pfenv, b, buf + INT_BUF_SIZE - b, flags, fill, width);
+    len += pfenv_print_strn(pfenv, str, fmt_size, flags, fill, width);
+
+    if (buf != stack_buf) {
+        m_free(buf, buf_size);
+    }
     return len;
 }
 

py/pfenv.h

-#define PF_FLAG_LEFT_ADJUST     (0x001)
-#define PF_FLAG_SHOW_SIGN       (0x002)
-#define PF_FLAG_SPACE_SIGN      (0x004)
-#define PF_FLAG_NO_TRAILZ       (0x008)
-#define PF_FLAG_SHOW_PREFIX     (0x010)
-#define PF_FLAG_SHOW_COMMA      (0x020)
-#define PF_FLAG_PAD_AFTER_SIGN  (0x040)
-#define PF_FLAG_CENTER_ADJUST   (0x080)
-#define PF_FLAG_ADD_PERCENT     (0x100)
-#define PF_FLAG_PAD_NAN_INF     (0x200)
+#define PF_FLAG_LEFT_ADJUST       (0x001)
+#define PF_FLAG_SHOW_SIGN         (0x002)
+#define PF_FLAG_SPACE_SIGN        (0x004)
+#define PF_FLAG_NO_TRAILZ         (0x008)
+#define PF_FLAG_SHOW_PREFIX       (0x010)
+#define PF_FLAG_SHOW_COMMA        (0x020)
+#define PF_FLAG_PAD_AFTER_SIGN    (0x040)
+#define PF_FLAG_CENTER_ADJUST     (0x080)
+#define PF_FLAG_ADD_PERCENT       (0x100)
+#define PF_FLAG_PAD_NAN_INF       (0x200)
+#define PF_FLAG_SHOW_OCTAL_LETTER (0x400)
 
 typedef struct _pfenv_t {
     void *data;
@@ -17,7 +18,7 @@ typedef struct _pfenv_t {
 void pfenv_vstr_add_strn(void *data, const char *str, unsigned int len);
 
 int pfenv_print_strn(const pfenv_t *pfenv, const char *str, unsigned int len, int flags, char fill, int width);
-int pfenv_print_int(const pfenv_t *pfenv, machine_uint_t x, int sgn, int base, int base_char, int flags, char fill, int width);
+int pfenv_print_int(const pfenv_t *pfenv, mp_obj_t x, int sgn, int base, int base_char, int flags, char fill, int width);
 #if MICROPY_ENABLE_FLOAT
 int pfenv_print_float(const pfenv_t *pfenv, mp_float_t f, char fmt, int flags, char fill, int width, int prec);
 #endif

tests/basics/string-format-modulo.py

@@ -53,6 +53,7 @@ print("%X" % 18)
 print("%X" % 18.0)
 print("%#x" % 18)
 print("%#X" % 18)
+print("%#6o" % 18)
 print("%#6x" % 18)
 print("%#06x" % 18)
 print("%e" % 1.23456)

tests/basics/string-format.py

@@ -24,11 +24,19 @@ test("{:4o}", 123)
 test("{:4x}", 123)
 test("{:4X}", 123)
 
+test("{:4,d}", 12345678)
+
 test("{:#4b}", 10)
 test("{:#4o}", 123)
 test("{:#4x}", 123)
 test("{:#4X}", 123)
 
+test("{:#4d}", 0)
+test("{:#4b}", 0)
+test("{:#4o}", 0)
+test("{:#4x}", 0)
+test("{:#4X}", 0)
+
 test("{:<6s}", "ab")
 test("{:>6s}", "ab")
 test("{:^6s}", "ab")