Least stack-usage self-contained ftostr32np()
This is the optimal code for a self-contained formatter, although the original code is crafty in being smaller and simpler, and can be evaluated as using the original output as a scratch pad for state, making the final formatter more straightforward. While this code is longer, all code-paths are minimal.
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1 changed files with 41 additions and 8 deletions
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@ -1445,16 +1445,49 @@ char *ftostr12ns(const float &x)
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// convert float to space-padded string with -_23.4_ format
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char *ftostr32np(const float &x) {
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char *c = ftostr32(x);
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if (c[0] == '0' || c[0] == '-') {
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if (c[0] == '0') c[0] = ' ';
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if (c[1] == '0') c[1] = ' ';
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long xx = abs(x * 100);
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uint8_t dig;
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if (x < 0) { // negative val = -_0
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conv[0] = '-';
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dig = (xx / 1000) % 10;
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conv[1] = dig ? '0' + dig : ' ';
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}
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if (c[5] == '0') {
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c[5] = ' ';
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if (c[4] == '0') c[4] = c[3] = ' ';
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else { // positive val = __0
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dig = (xx / 10000) % 10;
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if (dig) {
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conv[0] = '0' + dig;
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conv[1] = '0' + (xx / 1000) % 10;
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}
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else {
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conv[0] = ' ';
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dig = (xx / 1000) % 10;
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conv[1] = dig ? '0' + dig : ' ';
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}
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}
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return c;
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conv[2] = '0' + (xx / 100) % 10; // lsd always
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dig = xx % 10;
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if (dig) { // 2 decimal places
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conv[5] = '0' + dig;
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dig = (xx / 10) % 10;
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conv[4] = '0' + dig;
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conv[3] = '.';
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}
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else { // 1 or 0 decimal place
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dig = (xx / 10) % 10;
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if (dig) {
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conv[4] = '0' + dig;
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conv[3] = '.';
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}
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else {
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conv[3] = conv[4] = ' ';
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}
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conv[5] = ' ';
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}
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conv[6] = '\0';
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return conv;
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}
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char *itostr31(const int &xx)
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