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rt.aApply

This code handles decoding UTF strings for foreach loops.
Authors:
Walter Bright
alias dg_t = int delegate(void* c);
Delegate type corresponding to transformed loop body
The parameter is a pointer to the current char, wchar or dchar
Returns:
non-zero when a break statement is hit
int _aApplycd1(in char[] aa, dg_t dg);

int _aApplywd1(in wchar[] aa, dg_t dg);

int _aApplycw1(in char[] aa, dg_t dg);

int _aApplywc1(in wchar[] aa, dg_t dg);

int _aApplydc1(in dchar[] aa, dg_t dg);

int _aApplydw1(in dchar[] aa, dg_t dg);
Loop over a string while changing the UTF encoding
There are 6 combinations of conversions between char, wchar, and dchar, and 2 of each of those.
The naming convention is as follows:
aApply{c,d,w}{c,d,w}{1,2}
The first letter corresponds to the input string encoding, and the second letter corresponds to the target character type.
  • c = char
  • w = wchar
  • d = dchar
The 1 variant only produces the character, the 2 variant also produces a loop index.
Examples:
void main()
{
    string str;
    wtring wstr;
    dstring dstr;

    foreach (dchar c; str) {}
    // _aApplycd1

    foreach (wchar c; dstr) {}
    // _aApplydw1

    foreach (i, wchar c; str) {}
    // _aApplycw2

    foreach (wchar w; wstr) {}
    // no conversion
}
Parameters:
char[] aa input string
dg_t dg foreach body transformed into a delegate, similar to opApply
Returns:
non-zero when the loop was exited through a break
alias dg2_t = int delegate(void* i, void* c);
Delegate type corresponding to transformed loop body
Parameters are pointers to a size_t loop index, and the current char, wchar or dchar.
Returns:
non-zero when a break statement is hit
int _aApplycd2(in char[] aa, dg2_t dg);

int _aApplywd2(in wchar[] aa, dg2_t dg);

int _aApplycw2(in char[] aa, dg2_t dg);

int _aApplywc2(in wchar[] aa, dg2_t dg);

int _aApplydc2(in dchar[] aa, dg2_t dg);

int _aApplydw2(in dchar[] aa, dg2_t dg);
Variants of aApplyXXX that include a loop index.