Enhance str.format support

This adds support for almost everything (the comma isn't currently
supported).

The "unspecified" type with floats also doesn't behave exactly like
python.

Tested under unix with float and double
Spot tested on stmhal

1 files changed, 28 insertions, 122 deletions

diff --git a/stmhal/printf.c b/stmhal/printf.c
index 6fd06508e..b1eace28d 100644
--- a/stmhal/printf.c
+++ b/stmhal/printf.c
@@ -8,6 +8,7 @@
 #include "mpconfig.h"
 #include "qstr.h"
 #include "obj.h"
+#include "pfenv.h"
 #if 0
 #include "lcd.h"
 #endif
@@ -18,89 +19,6 @@
 #include "formatfloat.h"
 #endif
 
-#define PF_FLAG_LEFT_ADJUST (0x01)
-#define PF_FLAG_SHOW_SIGN   (0x02)
-#define PF_FLAG_SPACE_SIGN  (0x04)
-#define PF_FLAG_NO_TRAILZ   (0x08)
-#define PF_FLAG_ZERO_PAD    (0x10)
-
-// tricky; we compute pad string by: pad_chars + (flags & PF_FLAG_ZERO_PAD)
-#define PF_PAD_SIZE PF_FLAG_ZERO_PAD
-static const char *pad_chars = "                0000000000000000";
-
-typedef struct _pfenv_t {
-    void *data;
-    void (*print_strn)(void *, const char *str, unsigned int len);
-} pfenv_t;
-
-static void print_str_dummy(void *data, const char *str, unsigned int len) {
-}
-
-const pfenv_t pfenv_dummy = {0, print_str_dummy};
-
-static int pfenv_print_strn(const pfenv_t *pfenv, const char *str, unsigned int len, int flags, int width) {
-    int pad = width - len;
-    if (pad > 0 && (flags & PF_FLAG_LEFT_ADJUST) == 0) {
-        while (pad > 0) {
-            int p = pad;
-            if (p > PF_PAD_SIZE)
-                p = PF_PAD_SIZE;
-            pfenv->print_strn(pfenv->data, pad_chars + (flags & PF_FLAG_ZERO_PAD), p);
-            pad -= p;
-        }
-    }
-    pfenv->print_strn(pfenv->data, str, len);
-    while (pad > 0) {
-        int p = pad;
-        if (p > PF_PAD_SIZE)
-            p = PF_PAD_SIZE;
-        pfenv->print_strn(pfenv->data, pad_chars, p);
-        pad -= p;
-    }
-    return len;
-}
-
-// enough room for 32 signed number
-#define INT_BUF_SIZE (12)
-
-static int pfenv_print_int(const pfenv_t *pfenv, unsigned int x, int sgn, int base, int base_char, int flags, int width) {
-    char sign = 0;
-    if (sgn) {
-        if ((int)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);
-    }
-
-    if (b > buf && sign != 0) {
-        *(--b) = sign;
-    }
-
-    return pfenv_print_strn(pfenv, b, buf + INT_BUF_SIZE - b, flags, width);
-}
-
 void pfenv_prints(const pfenv_t *pfenv, const char *str) {
     pfenv->print_strn(pfenv->data, str, strlen(str));
 }
@@ -129,13 +47,16 @@ int pfenv_printf(const pfenv_t *pfenv, const char *fmt, va_list args) {
 
         // 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_ZERO_PAD;
-            else break;
+            else if (*fmt == '0') {
+                flags |= PF_FLAG_PAD_AFTER_SIGN;
+                fill = '0';
+            } else break;
             ++fmt;
         }
 
@@ -177,15 +98,15 @@ int pfenv_printf(const pfenv_t *pfenv, const char *fmt, va_list args) {
         switch (*fmt) {
             case 'b':
                 if (va_arg(args, int)) {
-                    chrs += pfenv_print_strn(pfenv, "true", 4, flags, width);
+                    chrs += pfenv_print_strn(pfenv, "true", 4, flags, fill, width);
                 } else {
-                    chrs += pfenv_print_strn(pfenv, "false", 5, flags, width);
+                    chrs += pfenv_print_strn(pfenv, "false", 5, flags, fill, width);
                 }
                 break;
             case 'c':
             {
                 char str = va_arg(args, int);
-                chrs += pfenv_print_strn(pfenv, &str, 1, flags, width);
+                chrs += pfenv_print_strn(pfenv, &str, 1, flags, fill, width);
                 break;
             }
             case 's':
@@ -195,25 +116,25 @@ int pfenv_printf(const pfenv_t *pfenv, const char *fmt, va_list args) {
                     if (prec < 0) {
                         prec = strlen(str);
                     }
-                    chrs += pfenv_print_strn(pfenv, str, prec, flags, width);
+                    chrs += pfenv_print_strn(pfenv, str, prec, flags, fill, width);
                 } else {
-                    chrs += pfenv_print_strn(pfenv, "(null)", 6, flags, width);
+                    chrs += pfenv_print_strn(pfenv, "(null)", 6, flags, fill, width);
                 }
                 break;
             }
             case 'u':
-                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 10, 'a', flags, width);
+                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 10, 'a', flags, fill, width);
                 break;
             case 'd':
-                chrs += pfenv_print_int(pfenv, va_arg(args, int), 1, 10, 'a', flags, width);
+                chrs += pfenv_print_int(pfenv, va_arg(args, int), 1, 10, 'a', flags, fill, width);
                 break;
             case 'x':
             case 'p': // ?
-                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 16, 'a', flags, width);
+                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 16, 'a', flags, fill, width);
                 break;
             case 'X':
             case 'P': // ?
-                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 16, 'A', flags, width);
+                chrs += pfenv_print_int(pfenv, va_arg(args, int), 0, 16, 'A', flags, fill, width);
                 break;
 #if MICROPY_ENABLE_FLOAT
             case 'e':
@@ -223,33 +144,18 @@ int pfenv_printf(const pfenv_t *pfenv, const char *fmt, va_list args) {
             case 'g':
             case 'G':
             {
-                char buf[32];
-                char sign = '\0';
-
-                if (flags & PF_FLAG_SHOW_SIGN) {
-                    sign = '+';
-                }
-                else
-                if (flags & PF_FLAG_SPACE_SIGN) {
-                    sign = ' ';
-                }
-                float f = va_arg(args, double);
-                int len = format_float(f, buf, sizeof(buf), *fmt, prec, sign);
-                char *s = buf;
-
-                // buf[0] < '0' returns true if the first character is space, + or -
-                // buf[1] < '9' matches a digit, and doesn't match when we get back +nan or +inf
-                if (buf[0] < '0' && buf[1] <= '9' && (flags & PF_FLAG_ZERO_PAD)) {
-                    chrs += pfenv_print_strn(pfenv, &buf[0], 1, 0, 1);
-                    s++;
-                    width--;
-                    len--;
-                }
-                if (*s < '0' || *s >= '9') {
-                    // For inf or nan, we don't want to zero pad.
-                    flags &= ~PF_FLAG_ZERO_PAD;
-                }
-                chrs += pfenv_print_strn(pfenv, s, len, flags, width); 
+#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+                mp_float_t f = va_arg(args, double);
+                chrs += pfenv_print_float(pfenv, f, *fmt, flags, fill, width, prec);
+#elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
+                // Currently pfenv_print_float uses snprintf, so if you want
+                // to use pfenv_print_float with doubles then you'll need
+                // fix it to not use snprintf first. Otherwise you'll have
+                // inifinite recursion.
+#error Calling pfenv_print_float with double not supported from within printf
+#else
+#error Unknown MICROPY FLOAT IMPL
+#endif
                 break;
             }
 #endif
@@ -338,7 +244,7 @@ void strn_print_strn(void *data, const char *str, unsigned int len) {
     strn_pfenv->cur += len;
     strn_pfenv->remain -= len;
 }
-
+    
 int vsnprintf(char *str, size_t size, const char *fmt, va_list ap) {
     strn_pfenv_t strn_pfenv;
     strn_pfenv.cur = str;