fn nextWithStrategy(self: *Windows, comptime strategy: type) strategy.T {
var last_emitted_code_unit: ?u16 = null;
// The first argument (the executable name) uses different parsing rules.
if (self.index == 0) {
if (self.cmd_line.len == 0 or self.cmd_line[0] == 0) {
// Immediately complete the iterator.
// The C runtime would return the name of the current executable here.
return strategy.eof;
}
var inside_quotes = false;
while (true) : (self.index += 1) {
const char = if (self.index != self.cmd_line.len)
std.mem.littleToNative(u16, self.cmd_line[self.index])
else
0;
switch (char) {
0 => {
return strategy.yieldArg(self);
},
'"' => {
inside_quotes = !inside_quotes;
},
' ', '\t' => {
if (inside_quotes) {
last_emitted_code_unit = strategy.emitCharacter(self, char, last_emitted_code_unit);
} else {
self.index += 1;
return strategy.yieldArg(self);
}
},
else => {
last_emitted_code_unit = strategy.emitCharacter(self, char, last_emitted_code_unit);
},
}
}
}
// Skip spaces and tabs. The iterator completes if we reach the end of the string here.
while (true) : (self.index += 1) {
const char = if (self.index != self.cmd_line.len)
std.mem.littleToNative(u16, self.cmd_line[self.index])
else
0;
switch (char) {
0 => return strategy.eof,
' ', '\t' => continue,
else => break,
}
}
// Parsing rules for subsequent arguments:
//
// - The end of the string always terminates the current argument.
// - When not in 'inside_quotes' mode, a space or tab terminates the current argument.
// - 2n backslashes followed by a quote emit n backslashes (note: n can be zero).
// If in 'inside_quotes' and the quote is immediately followed by a second quote,
// one quote is emitted and the other is skipped, otherwise, the quote is skipped
// and 'inside_quotes' is toggled.
// - 2n + 1 backslashes followed by a quote emit n backslashes followed by a quote.
// - n backslashes not followed by a quote emit n backslashes.
var backslash_count: usize = 0;
var inside_quotes = false;
while (true) : (self.index += 1) {
const char = if (self.index != self.cmd_line.len)
std.mem.littleToNative(u16, self.cmd_line[self.index])
else
0;
switch (char) {
0 => {
last_emitted_code_unit = strategy.emitBackslashes(self, backslash_count, last_emitted_code_unit);
return strategy.yieldArg(self);
},
' ', '\t' => {
last_emitted_code_unit = strategy.emitBackslashes(self, backslash_count, last_emitted_code_unit);
backslash_count = 0;
if (inside_quotes) {
last_emitted_code_unit = strategy.emitCharacter(self, char, last_emitted_code_unit);
} else return strategy.yieldArg(self);
},
'"' => {
const char_is_escaped_quote = backslash_count % 2 != 0;
last_emitted_code_unit = strategy.emitBackslashes(self, backslash_count / 2, last_emitted_code_unit);
backslash_count = 0;
if (char_is_escaped_quote) {
last_emitted_code_unit = strategy.emitCharacter(self, '"', last_emitted_code_unit);
} else {
if (inside_quotes and
self.index + 1 != self.cmd_line.len and
std.mem.littleToNative(u16, self.cmd_line[self.index + 1]) == '"')
{
last_emitted_code_unit = strategy.emitCharacter(self, '"', last_emitted_code_unit);
self.index += 1;
} else {
inside_quotes = !inside_quotes;
}
}
},
'\\' => {
backslash_count += 1;
},
else => {
last_emitted_code_unit = strategy.emitBackslashes(self, backslash_count, last_emitted_code_unit);
backslash_count = 0;
last_emitted_code_unit = strategy.emitCharacter(self, char, last_emitted_code_unit);
},
}
}
}
