py/mpprint.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the Micro Python project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013-2015 Damien P. George
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include <assert.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>

 #include "py/mpprint.h"
 #include "py/obj.h"
 #include "py/objint.h"
 #include "py/runtime.h"

 #if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
 #include <stdio.h>
 #endif

 #if MICROPY_PY_BUILTINS_FLOAT
 #include "py/formatfloat.h"
 #endif

 static const char pad_spaces[] = "                ";
 static const char pad_zeroes[] = "0000000000000000";

 STATIC void plat_print_strn(void *env, const char *str, mp_uint_t len) {
     (void)env;
     MP_PLAT_PRINT_STRN(str, len);
 }

 const mp_print_t mp_plat_print = {NULL, plat_print_strn};

 int mp_print_str(const mp_print_t *print, const char *str) {
     mp_uint_t len = strlen(str);
     if (len) {
         print->print_strn(print->data, str, len);
     }
     return len;
 }

 int mp_print_strn(const mp_print_t *print, const char *str, mp_uint_t len, int flags, char fill, int width) {
     int left_pad = 0;
     int right_pad = 0;
     int pad = width - len;
     int pad_size;
     int total_chars_printed = 0;
     const char *pad_chars;

     if (!fill || fill == ' ') {
         pad_chars = pad_spaces;
         pad_size = sizeof(pad_spaces) - 1;
     } else if (fill == '0') {
         pad_chars = pad_zeroes;
         pad_size = sizeof(pad_zeroes) - 1;
     } else {
         // Other pad characters are fairly unusual, so we'll take the hit
         // and output them 1 at a time.
         pad_chars = &fill;
         pad_size = 1;
     }

     if (flags & PF_FLAG_CENTER_ADJUST) {
         left_pad = pad / 2;
         right_pad = pad - left_pad;
     } else if (flags & PF_FLAG_LEFT_ADJUST) {
         right_pad = pad;
     } else {
         left_pad = pad;
     }

     if (left_pad > 0) {
         total_chars_printed += left_pad;
         while (left_pad > 0) {
             int p = left_pad;
             if (p > pad_size) {
                 p = pad_size;
             }
             print->print_strn(print->data, pad_chars, p);
             left_pad -= p;
         }
     }
     if (len) {
         print->print_strn(print->data, str, len);
         total_chars_printed += len;
     }
     if (right_pad > 0) {
         total_chars_printed += right_pad;
         while (right_pad > 0) {
             int p = right_pad;
             if (p > pad_size) {
                 p = pad_size;
             }
             print->print_strn(print->data, pad_chars, p);
             right_pad -= p;
         }
     }
     return total_chars_printed;
 }

 // 32-bits is 10 digits, add 3 for commas, 1 for sign, 1 for terminating null
 // We can use 16 characters for 32-bit and 32 characters for 64-bit
 #define INT_BUF_SIZE (sizeof(mp_int_t) * 4)

 // This function is used by stmhal port to implement printf.
 // It needs to be a separate function to mp_print_mp_int, since converting to a mp_int looses the MSB.
 int mp_print_int(const mp_print_t *print, mp_uint_t x, int sgn, int base, int base_char, int flags, char fill, int width) {
     char sign = 0;
     if (sgn) {
         if ((mp_int_t)x < 0) {
             sign = '-';
             x = -x;
         } else if (flags & PF_FLAG_SHOW_SIGN) {
             sign = '+';
         } else if (flags & PF_FLAG_SPACE_SIGN) {
             sign = ' ';
         }
     }

     char buf[INT_BUF_SIZE];
     char *b = buf + INT_BUF_SIZE;

     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);
     }

     char prefix_char = '\0';

     if (flags & PF_FLAG_SHOW_PREFIX) {
         if (base == 2) {
             prefix_char = base_char + 'b' - 'a';
         } else if (base == 8) {
             prefix_char = base_char + 'o' - 'a';
         } else if (base == 16) {
             prefix_char = base_char + 'x' - 'a';
         }
     }

     int len = 0;
     if (flags & PF_FLAG_PAD_AFTER_SIGN) {
         if (sign) {
             len += mp_print_strn(print, &sign, 1, flags, fill, 1);
             width--;
         }
         if (prefix_char) {
             len += mp_print_strn(print, "0", 1, flags, fill, 1);
             len += mp_print_strn(print, &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;
         }
     }

     len += mp_print_strn(print, b, buf + INT_BUF_SIZE - b, flags, fill, width);
     return len;
 }

 int mp_print_mp_int(const mp_print_t *print, mp_obj_t x, int base, int base_char, int flags, char fill, int width, int prec) {
     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));
     }

     if ((flags & (PF_FLAG_LEFT_ADJUST | PF_FLAG_CENTER_ADJUST)) == 0 && fill == '0') {
         if (prec > width) {
             width = prec;
         }
         prec = 0;
     }
     char prefix_buf[4];
     char *prefix = prefix_buf;

     if (mp_obj_int_is_positive(x)) {
         if (flags & PF_FLAG_SHOW_SIGN) {
             *prefix++ = '+';
         } else if (flags & PF_FLAG_SPACE_SIGN) {
             *prefix++ = ' ';
         }
     }

     if (flags & PF_FLAG_SHOW_PREFIX) {
         if (base == 2) {
             *prefix++ = '0';
             *prefix++ = base_char + 'b' - 'a';
         } else if (base == 8) {
             *prefix++ = '0';
             if (flags & PF_FLAG_SHOW_OCTAL_LETTER) {
                 *prefix++ = base_char + 'o' - 'a';
             }
         } else if (base == 16) {
             *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(mp_int_t) * 4];
     char *buf = stack_buf;
     mp_uint_t buf_size = sizeof(stack_buf);
     mp_uint_t fmt_size = 0;
     char *str;

     if (prec > 1) {
         flags |= PF_FLAG_PAD_AFTER_SIGN;
     }
     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 spaces_before = 0;
     int spaces_after = 0;

     if (prec > 1) {
         // If prec was specified, then prec specifies the width to zero-pad the
         // the number to. This zero-padded number then gets left or right
         // aligned in width characters.

         int prec_width = fmt_size;  // The digits
         if (prec_width < prec) {
             prec_width = prec;
         }
         if (flags & PF_FLAG_PAD_AFTER_SIGN) {
             if (sign) {
                 prec_width++;
             }
             prec_width += prefix_len;
         }
         if (prec_width < width) {
             if (flags & PF_FLAG_LEFT_ADJUST) {
                 spaces_after = width - prec_width;
             } else {
                 spaces_before = width - prec_width;
             }
         }
         fill = '0';
         flags &= ~PF_FLAG_LEFT_ADJUST;
     }

     int len = 0;
     if (spaces_before) {
         len += mp_print_strn(print, "", 0, 0, ' ', spaces_before);
     }
     if (flags & PF_FLAG_PAD_AFTER_SIGN) {
         // pad after sign implies pad after prefix as well.
         if (sign) {
             len += mp_print_strn(print, &sign, 1, 0, 0, 1);
             width--;
         }
         if (prefix_len) {
             len += mp_print_strn(print, prefix, prefix_len, 0, 0, 1);
             width -= prefix_len;
         }
     }
     if (prec > 1) {
         width = prec;
     }

     len += mp_print_strn(print, str, fmt_size, flags, fill, width);

     if (spaces_after) {
         len += mp_print_strn(print, "", 0, 0, ' ', spaces_after);
     }

     if (buf != stack_buf) {
         m_del(char, buf, buf_size);
     }
     return len;
 }

 #if MICROPY_PY_BUILTINS_FLOAT
 int mp_print_float(const mp_print_t *print, mp_float_t f, char fmt, int flags, char fill, int width, int prec) {
     char buf[32];
     char sign = '\0';
     int chrs = 0;

     if (flags & PF_FLAG_SHOW_SIGN) {
         sign = '+';
     }
     else
     if (flags & PF_FLAG_SPACE_SIGN) {
         sign = ' ';
     }
     int len;
 #if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
     len = mp_format_float(f, buf, sizeof(buf), fmt, prec, sign);
 #elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
     char fmt_buf[6];
     char *fmt_s = fmt_buf;

     *fmt_s++ = '%';
     if (sign) {
         *fmt_s++ = sign;
     }
     *fmt_s++ = '.';
     *fmt_s++ = '*';
     *fmt_s++ = fmt;
     *fmt_s = '\0';

     len = snprintf(buf, sizeof(buf), fmt_buf, prec, f);
     if (len < 0) {
         len = 0;
     }
 #else
 #error Unknown MICROPY FLOAT IMPL
 #endif
     char *s = buf;

     if ((flags & PF_FLAG_ADD_PERCENT) && (size_t)(len + 1) < sizeof(buf)) {
         buf[len++] = '%';
         buf[len] = '\0';
     }

     // buf[0] < '0' returns true if the first character is space, + or -
     if ((flags & PF_FLAG_PAD_AFTER_SIGN) && buf[0] < '0') {
         // We have a sign character
         s++;
         if (*s <= '9' || (flags & PF_FLAG_PAD_NAN_INF)) {
             // We have a number, or we have a inf/nan and PAD_NAN_INF is set
             // With '{:06e}'.format(float('-inf')) you get '-00inf'
             chrs += mp_print_strn(print, &buf[0], 1, 0, 0, 1);
             width--;
             len--;
         }
     }

     if (*s > 'A' && (flags & PF_FLAG_PAD_NAN_INF) == 0) {
         // We have one of the inf or nan variants, suppress zero fill.
         // With printf, if you use: printf("%06e", -inf) then you get "  -inf"
         // so suppress the zero fill.
         fill = ' ';
     }
     chrs += mp_print_strn(print, s, len, flags, fill, width);

     return chrs;
 }
 #endif

 int mp_printf(const mp_print_t *print, const char *fmt, ...) {
     va_list ap;
     va_start(ap, fmt);
     int ret = mp_vprintf(print, fmt, ap);
     va_end(ap);
     return ret;
 }

 int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args) {
     int chrs = 0;
     for (;;) {
         {
             const char *f = fmt;
             while (*f != '\0' && *f != '%') {
                 ++f; // XXX UTF8 advance char
             }
             if (f > fmt) {
                 print->print_strn(print->data, fmt, f - fmt);
                 chrs += f - fmt;
                 fmt = f;
             }
         }

         if (*fmt == '\0') {
             break;
         }

         // move past % character
         ++fmt;

         // parse flags, if they exist
         int flags = 0;
         char fill = ' ';
         while (*fmt != '\0') {
             if (*fmt == '-') flags |= PF_FLAG_LEFT_ADJUST;
             else if (*fmt == '+') flags |= PF_FLAG_SHOW_SIGN;
             else if (*fmt == ' ') flags |= PF_FLAG_SPACE_SIGN;
             else if (*fmt == '!') flags |= PF_FLAG_NO_TRAILZ;
             else if (*fmt == '0') {
                 flags |= PF_FLAG_PAD_AFTER_SIGN;
                 fill = '0';
             } else break;
             ++fmt;
         }

         // parse width, if it exists
         int width = 0;
         for (; '0' <= *fmt && *fmt <= '9'; ++fmt) {
             width = width * 10 + *fmt - '0';
         }

         // parse precision, if it exists
         int prec = -1;
         if (*fmt == '.') {
             ++fmt;
             if (*fmt == '*') {
                 ++fmt;
                 prec = va_arg(args, int);
             } else {
                 prec = 0;
                 for (; '0' <= *fmt && *fmt <= '9'; ++fmt) {
                     prec = prec * 10 + *fmt - '0';
                 }
             }
             if (prec < 0) {
                 prec = 0;
             }
         }

         // parse long specifiers (current not used)
         //bool long_arg = false;
         if (*fmt == 'l') {
             ++fmt;
             //long_arg = true;
         }

         if (*fmt == '\0') {
             break;
         }

         switch (*fmt) {
             case 'b':
                 if (va_arg(args, int)) {
                     chrs += mp_print_strn(print, "true", 4, flags, fill, width);
                 } else {
                     chrs += mp_print_strn(print, "false", 5, flags, fill, width);
                 }
                 break;
             case 'c':
             {
                 char str = va_arg(args, int);
                 chrs += mp_print_strn(print, &str, 1, flags, fill, width);
                 break;
             }
             case 's':
             {
                 const char *str = va_arg(args, const char*);
                 if (str) {
                     if (prec < 0) {
                         prec = strlen(str);
                     }
                     chrs += mp_print_strn(print, str, prec, flags, fill, width);
                 } else {
                     chrs += mp_print_strn(print, "(null)", 6, flags, fill, width);
                 }
                 break;
             }
             case 'u':
                 chrs += mp_print_int(print, va_arg(args, int), 0, 10, 'a', flags, fill, width);
                 break;
             case 'd':
                 chrs += mp_print_int(print, va_arg(args, int), 1, 10, 'a', flags, fill, width);
                 break;
             case 'x':
                 chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'a', flags, fill, width);
                 break;
             case 'X':
                 chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'A', flags, fill, width);
                 break;
             case 'p':
             case 'P': // don't bother to handle upcase for 'P'
                 chrs += mp_print_int(print, va_arg(args, unsigned int), 0, 16, 'a', flags, fill, width);
                 break;
 #if MICROPY_PY_BUILTINS_FLOAT
             case 'e':
             case 'E':
             case 'f':
             case 'F':
             case 'g':
             case 'G':
             {
 #if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
                 mp_float_t f = va_arg(args, double);
                 chrs += mp_print_float(print, f, *fmt, flags, fill, width, prec);
 #elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
                 // Currently mp_print_float uses snprintf, but snprintf
                 // itself may be implemented in terms of mp_vprintf() for
                 // some ports. So, for extra caution, this case is handled
                 // with assert below. Note that currently ports which
                 // use MICROPY_FLOAT_IMPL_DOUBLE, don't call mp_vprintf()
                 // with float format specifier at all.
                 // TODO: resolve this completely
                 assert(0);
 //#error Calling mp_print_float with double not supported from within printf
 #else
 #error Unknown MICROPY FLOAT IMPL
 #endif
                 break;
             }
 #endif
             default:
                 print->print_strn(print->data, fmt, 1);
                 chrs += 1;
                 break;
         }
         ++fmt;
     }
     return chrs;
 }
	/*
	* This file is part of the Micro Python project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013-2015 Damien P. George
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include <assert.h>
	#include <stdarg.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <string.h>

	#include "py/mpprint.h"
	#include "py/obj.h"
	#include "py/objint.h"
	#include "py/runtime.h"

	#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
	#include <stdio.h>
	#endif

	#if MICROPY_PY_BUILTINS_FLOAT
	#include "py/formatfloat.h"
	#endif

	static const char pad_spaces[] = " ";
	static const char pad_zeroes[] = "0000000000000000";

	STATIC void plat_print_strn(void env, const char str, mp_uint_t len) {
	(void)env;
	MP_PLAT_PRINT_STRN(str, len);
	}

	const mp_print_t mp_plat_print = {NULL, plat_print_strn};

	int mp_print_str(const mp_print_t print, const char str) {
	mp_uint_t len = strlen(str);
	if (len) {
	print->print_strn(print->data, str, len);
	}
	return len;
	}

	int mp_print_strn(const mp_print_t print, const char str, mp_uint_t len, int flags, char fill, int width) {
	int left_pad = 0;
	int right_pad = 0;
	int pad = width - len;
	int pad_size;
	int total_chars_printed = 0;
	const char *pad_chars;

	if (!fill \|\| fill == ' ') {
	pad_chars = pad_spaces;
	pad_size = sizeof(pad_spaces) - 1;
	} else if (fill == '0') {
	pad_chars = pad_zeroes;
	pad_size = sizeof(pad_zeroes) - 1;
	} else {
	// Other pad characters are fairly unusual, so we'll take the hit
	// and output them 1 at a time.
	pad_chars = &fill;
	pad_size = 1;
	}

	if (flags & PF_FLAG_CENTER_ADJUST) {
	left_pad = pad / 2;
	right_pad = pad - left_pad;
	} else if (flags & PF_FLAG_LEFT_ADJUST) {
	right_pad = pad;
	} else {
	left_pad = pad;
	}

	if (left_pad > 0) {
	total_chars_printed += left_pad;
	while (left_pad > 0) {
	int p = left_pad;
	if (p > pad_size) {
	p = pad_size;
	}
	print->print_strn(print->data, pad_chars, p);
	left_pad -= p;
	}
	}
	if (len) {
	print->print_strn(print->data, str, len);
	total_chars_printed += len;
	}
	if (right_pad > 0) {
	total_chars_printed += right_pad;
	while (right_pad > 0) {
	int p = right_pad;
	if (p > pad_size) {
	p = pad_size;
	}
	print->print_strn(print->data, pad_chars, p);
	right_pad -= p;
	}
	}
	return total_chars_printed;
	}

	// 32-bits is 10 digits, add 3 for commas, 1 for sign, 1 for terminating null
	// We can use 16 characters for 32-bit and 32 characters for 64-bit
	#define INT_BUF_SIZE (sizeof(mp_int_t) * 4)

	// This function is used by stmhal port to implement printf.
	// It needs to be a separate function to mp_print_mp_int, since converting to a mp_int looses the MSB.
	int mp_print_int(const mp_print_t *print, mp_uint_t x, int sgn, int base, int base_char, int flags, char fill, int width) {
	char sign = 0;
	if (sgn) {
	if ((mp_int_t)x < 0) {
	sign = '-';
	x = -x;
	} else if (flags & PF_FLAG_SHOW_SIGN) {
	sign = '+';
	} else if (flags & PF_FLAG_SPACE_SIGN) {
	sign = ' ';
	}
	}

	char buf[INT_BUF_SIZE];
	char *b = buf + INT_BUF_SIZE;

	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);
	}

	char prefix_char = '\0';

	if (flags & PF_FLAG_SHOW_PREFIX) {
	if (base == 2) {
	prefix_char = base_char + 'b' - 'a';
	} else if (base == 8) {
	prefix_char = base_char + 'o' - 'a';
	} else if (base == 16) {
	prefix_char = base_char + 'x' - 'a';
	}
	}

	int len = 0;
	if (flags & PF_FLAG_PAD_AFTER_SIGN) {
	if (sign) {
	len += mp_print_strn(print, &sign, 1, flags, fill, 1);
	width--;
	}
	if (prefix_char) {
	len += mp_print_strn(print, "0", 1, flags, fill, 1);
	len += mp_print_strn(print, &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;
	}
	}

	len += mp_print_strn(print, b, buf + INT_BUF_SIZE - b, flags, fill, width);
	return len;
	}

	int mp_print_mp_int(const mp_print_t *print, mp_obj_t x, int base, int base_char, int flags, char fill, int width, int prec) {
	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));
	}

	if ((flags & (PF_FLAG_LEFT_ADJUST \| PF_FLAG_CENTER_ADJUST)) == 0 && fill == '0') {
	if (prec > width) {
	width = prec;
	}
	prec = 0;
	}
	char prefix_buf[4];
	char *prefix = prefix_buf;

	if (mp_obj_int_is_positive(x)) {
	if (flags & PF_FLAG_SHOW_SIGN) {
	*prefix++ = '+';
	} else if (flags & PF_FLAG_SPACE_SIGN) {
	*prefix++ = ' ';
	}
	}

	if (flags & PF_FLAG_SHOW_PREFIX) {
	if (base == 2) {
	*prefix++ = '0';
	*prefix++ = base_char + 'b' - 'a';
	} else if (base == 8) {
	*prefix++ = '0';
	if (flags & PF_FLAG_SHOW_OCTAL_LETTER) {
	*prefix++ = base_char + 'o' - 'a';
	}
	} else if (base == 16) {
	*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(mp_int_t) * 4];
	char *buf = stack_buf;
	mp_uint_t buf_size = sizeof(stack_buf);
	mp_uint_t fmt_size = 0;
	char *str;

	if (prec > 1) {
	flags \|= PF_FLAG_PAD_AFTER_SIGN;
	}
	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 spaces_before = 0;
	int spaces_after = 0;

	if (prec > 1) {
	// If prec was specified, then prec specifies the width to zero-pad the
	// the number to. This zero-padded number then gets left or right
	// aligned in width characters.

	int prec_width = fmt_size; // The digits
	if (prec_width < prec) {
	prec_width = prec;
	}
	if (flags & PF_FLAG_PAD_AFTER_SIGN) {
	if (sign) {
	prec_width++;
	}
	prec_width += prefix_len;
	}
	if (prec_width < width) {
	if (flags & PF_FLAG_LEFT_ADJUST) {
	spaces_after = width - prec_width;
	} else {
	spaces_before = width - prec_width;
	}
	}
	fill = '0';
	flags &= ~PF_FLAG_LEFT_ADJUST;
	}

	int len = 0;
	if (spaces_before) {
	len += mp_print_strn(print, "", 0, 0, ' ', spaces_before);
	}
	if (flags & PF_FLAG_PAD_AFTER_SIGN) {
	// pad after sign implies pad after prefix as well.
	if (sign) {
	len += mp_print_strn(print, &sign, 1, 0, 0, 1);
	width--;
	}
	if (prefix_len) {
	len += mp_print_strn(print, prefix, prefix_len, 0, 0, 1);
	width -= prefix_len;
	}
	}
	if (prec > 1) {
	width = prec;
	}

	len += mp_print_strn(print, str, fmt_size, flags, fill, width);

	if (spaces_after) {
	len += mp_print_strn(print, "", 0, 0, ' ', spaces_after);
	}

	if (buf != stack_buf) {
	m_del(char, buf, buf_size);
	}
	return len;
	}

	#if MICROPY_PY_BUILTINS_FLOAT
	int mp_print_float(const mp_print_t *print, mp_float_t f, char fmt, int flags, char fill, int width, int prec) {
	char buf[32];
	char sign = '\0';
	int chrs = 0;

	if (flags & PF_FLAG_SHOW_SIGN) {
	sign = '+';
	}
	else
	if (flags & PF_FLAG_SPACE_SIGN) {
	sign = ' ';
	}
	int len;
	#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
	len = mp_format_float(f, buf, sizeof(buf), fmt, prec, sign);
	#elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
	char fmt_buf[6];
	char *fmt_s = fmt_buf;

	*fmt_s++ = '%';
	if (sign) {
	*fmt_s++ = sign;
	}
	*fmt_s++ = '.';
	fmt_s++ = '';
	*fmt_s++ = fmt;
	*fmt_s = '\0';

	len = snprintf(buf, sizeof(buf), fmt_buf, prec, f);
	if (len < 0) {
	len = 0;
	}
	#else
	#error Unknown MICROPY FLOAT IMPL
	#endif
	char *s = buf;

	if ((flags & PF_FLAG_ADD_PERCENT) && (size_t)(len + 1) < sizeof(buf)) {
	buf[len++] = '%';
	buf[len] = '\0';
	}

	// buf[0] < '0' returns true if the first character is space, + or -
	if ((flags & PF_FLAG_PAD_AFTER_SIGN) && buf[0] < '0') {
	// We have a sign character
	s++;
	if (*s <= '9' \|\| (flags & PF_FLAG_PAD_NAN_INF)) {
	// We have a number, or we have a inf/nan and PAD_NAN_INF is set
	// With '{:06e}'.format(float('-inf')) you get '-00inf'
	chrs += mp_print_strn(print, &buf[0], 1, 0, 0, 1);
	width--;
	len--;
	}
	}

	if (*s > 'A' && (flags & PF_FLAG_PAD_NAN_INF) == 0) {
	// We have one of the inf or nan variants, suppress zero fill.
	// With printf, if you use: printf("%06e", -inf) then you get " -inf"
	// so suppress the zero fill.
	fill = ' ';
	}
	chrs += mp_print_strn(print, s, len, flags, fill, width);

	return chrs;
	}
	#endif

	int mp_printf(const mp_print_t print, const char fmt, ...) {
	va_list ap;
	va_start(ap, fmt);
	int ret = mp_vprintf(print, fmt, ap);
	va_end(ap);
	return ret;
	}

	int mp_vprintf(const mp_print_t print, const char fmt, va_list args) {
	int chrs = 0;
	for (;;) {
	{
	const char *f = fmt;
	while (f != '\0' && f != '%') {
	++f; // XXX UTF8 advance char
	}
	if (f > fmt) {
	print->print_strn(print->data, fmt, f - fmt);
	chrs += f - fmt;
	fmt = f;
	}
	}

	if (*fmt == '\0') {
	break;
	}

	// move past % character
	++fmt;

	// parse flags, if they exist
	int flags = 0;
	char fill = ' ';
	while (*fmt != '\0') {
	if (*fmt == '-') flags \|= PF_FLAG_LEFT_ADJUST;
	else if (*fmt == '+') flags \|= PF_FLAG_SHOW_SIGN;
	else if (*fmt == ' ') flags \|= PF_FLAG_SPACE_SIGN;
	else if (*fmt == '!') flags \|= PF_FLAG_NO_TRAILZ;
	else if (*fmt == '0') {
	flags \|= PF_FLAG_PAD_AFTER_SIGN;
	fill = '0';
	} else break;
	++fmt;
	}

	// parse width, if it exists
	int width = 0;
	for (; '0' <= fmt && fmt <= '9'; ++fmt) {
	width = width * 10 + *fmt - '0';
	}

	// parse precision, if it exists
	int prec = -1;
	if (*fmt == '.') {
	++fmt;
	if (fmt == '') {
	++fmt;
	prec = va_arg(args, int);
	} else {
	prec = 0;
	for (; '0' <= fmt && fmt <= '9'; ++fmt) {
	prec = prec * 10 + *fmt - '0';
	}
	}
	if (prec < 0) {
	prec = 0;
	}
	}

	// parse long specifiers (current not used)
	//bool long_arg = false;
	if (*fmt == 'l') {
	++fmt;
	//long_arg = true;
	}

	if (*fmt == '\0') {
	break;
	}

	switch (*fmt) {
	case 'b':
	if (va_arg(args, int)) {
	chrs += mp_print_strn(print, "true", 4, flags, fill, width);
	} else {
	chrs += mp_print_strn(print, "false", 5, flags, fill, width);
	}
	break;
	case 'c':
	{
	char str = va_arg(args, int);
	chrs += mp_print_strn(print, &str, 1, flags, fill, width);
	break;
	}
	case 's':
	{
	const char str = va_arg(args, const char);
	if (str) {
	if (prec < 0) {
	prec = strlen(str);
	}
	chrs += mp_print_strn(print, str, prec, flags, fill, width);
	} else {
	chrs += mp_print_strn(print, "(null)", 6, flags, fill, width);
	}
	break;
	}
	case 'u':
	chrs += mp_print_int(print, va_arg(args, int), 0, 10, 'a', flags, fill, width);
	break;
	case 'd':
	chrs += mp_print_int(print, va_arg(args, int), 1, 10, 'a', flags, fill, width);
	break;
	case 'x':
	chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'a', flags, fill, width);
	break;
	case 'X':
	chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'A', flags, fill, width);
	break;
	case 'p':
	case 'P': // don't bother to handle upcase for 'P'
	chrs += mp_print_int(print, va_arg(args, unsigned int), 0, 16, 'a', flags, fill, width);
	break;
	#if MICROPY_PY_BUILTINS_FLOAT
	case 'e':
	case 'E':
	case 'f':
	case 'F':
	case 'g':
	case 'G':
	{
	#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
	mp_float_t f = va_arg(args, double);
	chrs += mp_print_float(print, f, *fmt, flags, fill, width, prec);
	#elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
	// Currently mp_print_float uses snprintf, but snprintf
	// itself may be implemented in terms of mp_vprintf() for
	// some ports. So, for extra caution, this case is handled
	// with assert below. Note that currently ports which
	// use MICROPY_FLOAT_IMPL_DOUBLE, don't call mp_vprintf()
	// with float format specifier at all.
	// TODO: resolve this completely
	assert(0);
	//#error Calling mp_print_float with double not supported from within printf
	#else
	#error Unknown MICROPY FLOAT IMPL
	#endif
	break;
	}
	#endif
	default:
	print->print_strn(print->data, fmt, 1);
	chrs += 1;
	break;
	}
	++fmt;
	}
	return chrs;
	}