Type Function ArgIteratorGeneral [src]
A general Iterator to parse a string into a set of arguments
Prototype
pub fn ArgIteratorGeneral(comptime options: ArgIteratorGeneralOptions) type Parameters
options: ArgIteratorGeneralOptions Source
pub fn ArgIteratorGeneral(comptime options: ArgIteratorGeneralOptions) type {
return struct {
allocator: Allocator,
index: usize = 0,
cmd_line: []const u8,
/// Should the cmd_line field be free'd (using the allocator) on deinit()?
free_cmd_line_on_deinit: bool,
/// buffer MUST be long enough to hold the cmd_line plus a null terminator.
/// buffer will we free'd (using the allocator) on deinit()
buffer: []u8,
start: usize = 0,
end: usize = 0,
pub const Self = @This();
pub const InitError = error{OutOfMemory};
/// cmd_line_utf8 MUST remain valid and constant while using this instance
pub fn init(allocator: Allocator, cmd_line_utf8: []const u8) InitError!Self {
const buffer = try allocator.alloc(u8, cmd_line_utf8.len + 1);
errdefer allocator.free(buffer);
return Self{
.allocator = allocator,
.cmd_line = cmd_line_utf8,
.free_cmd_line_on_deinit = false,
.buffer = buffer,
};
}
/// cmd_line_utf8 will be free'd (with the allocator) on deinit()
pub fn initTakeOwnership(allocator: Allocator, cmd_line_utf8: []const u8) InitError!Self {
const buffer = try allocator.alloc(u8, cmd_line_utf8.len + 1);
errdefer allocator.free(buffer);
return Self{
.allocator = allocator,
.cmd_line = cmd_line_utf8,
.free_cmd_line_on_deinit = true,
.buffer = buffer,
};
}
// Skips over whitespace in the cmd_line.
// Returns false if the terminating sentinel is reached, true otherwise.
// Also skips over comments (if supported).
fn skipWhitespace(self: *Self) bool {
while (true) : (self.index += 1) {
const character = if (self.index != self.cmd_line.len) self.cmd_line[self.index] else 0;
switch (character) {
0 => return false,
' ', '\t', '\r', '\n' => continue,
'#' => {
if (options.comments) {
while (true) : (self.index += 1) {
switch (self.cmd_line[self.index]) {
'\n' => break,
0 => return false,
else => continue,
}
}
continue;
} else {
break;
}
},
else => break,
}
}
return true;
}
pub fn skip(self: *Self) bool {
if (!self.skipWhitespace()) {
return false;
}
var backslash_count: usize = 0;
var in_quote = false;
while (true) : (self.index += 1) {
const character = if (self.index != self.cmd_line.len) self.cmd_line[self.index] else 0;
switch (character) {
0 => return true,
'"', '\'' => {
if (!options.single_quotes and character == '\'') {
backslash_count = 0;
continue;
}
const quote_is_real = backslash_count % 2 == 0;
if (quote_is_real) {
in_quote = !in_quote;
}
},
'\\' => {
backslash_count += 1;
},
' ', '\t', '\r', '\n' => {
if (!in_quote) {
return true;
}
backslash_count = 0;
},
else => {
backslash_count = 0;
continue;
},
}
}
}
/// Returns a slice of the internal buffer that contains the next argument.
/// Returns null when it reaches the end.
pub fn next(self: *Self) ?[:0]const u8 {
if (!self.skipWhitespace()) {
return null;
}
var backslash_count: usize = 0;
var in_quote = false;
while (true) : (self.index += 1) {
const character = if (self.index != self.cmd_line.len) self.cmd_line[self.index] else 0;
switch (character) {
0 => {
self.emitBackslashes(backslash_count);
self.buffer[self.end] = 0;
const token = self.buffer[self.start..self.end :0];
self.end += 1;
self.start = self.end;
return token;
},
'"', '\'' => {
if (!options.single_quotes and character == '\'') {
self.emitBackslashes(backslash_count);
backslash_count = 0;
self.emitCharacter(character);
continue;
}
const quote_is_real = backslash_count % 2 == 0;
self.emitBackslashes(backslash_count / 2);
backslash_count = 0;
if (quote_is_real) {
in_quote = !in_quote;
} else {
self.emitCharacter('"');
}
},
'\\' => {
backslash_count += 1;
},
' ', '\t', '\r', '\n' => {
self.emitBackslashes(backslash_count);
backslash_count = 0;
if (in_quote) {
self.emitCharacter(character);
} else {
self.buffer[self.end] = 0;
const token = self.buffer[self.start..self.end :0];
self.end += 1;
self.start = self.end;
return token;
}
},
else => {
self.emitBackslashes(backslash_count);
backslash_count = 0;
self.emitCharacter(character);
},
}
}
}
fn emitBackslashes(self: *Self, emit_count: usize) void {
var i: usize = 0;
while (i < emit_count) : (i += 1) {
self.emitCharacter('\\');
}
}
fn emitCharacter(self: *Self, char: u8) void {
self.buffer[self.end] = char;
self.end += 1;
}
/// Call to free the internal buffer of the iterator.
pub fn deinit(self: *Self) void {
self.allocator.free(self.buffer);
if (self.free_cmd_line_on_deinit) {
self.allocator.free(self.cmd_line);
}
}
};
}