diff options
Diffstat (limited to 'v_windows/v/vlib/flag/flag.v')
| -rw-r--r-- | v_windows/v/vlib/flag/flag.v | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/v_windows/v/vlib/flag/flag.v b/v_windows/v/vlib/flag/flag.v new file mode 100644 index 0000000..85bb09d --- /dev/null +++ b/v_windows/v/vlib/flag/flag.v @@ -0,0 +1,624 @@ +module flag + +// data object storing information about a defined flag +pub struct Flag { +pub: + name string // name as it appears on command line + abbr byte // shortcut + usage string // help message + val_desc string // something like '<arg>' that appears in usage, + // and also the default value, when the flag is not given +} + +struct UnkownFlagError { + msg string + code int +} + +struct MinimumArgsCountError { + msg string + code int +} + +struct MaximumArgsCountError { + msg string + code int +} + +struct NoArgsExpectedError { + msg string + code int +} + +[unsafe] +fn (mut f Flag) free() { + unsafe { + f.name.free() + f.usage.free() + f.val_desc.free() + } +} + +pub fn (f Flag) str() string { + return '' + ' flag:\n' + ' name: $f.name\n' + + ' abbr: `$f.abbr.ascii_str()`\n' + ' usag: $f.usage\n' + + ' desc: $f.val_desc' +} + +pub fn (af []Flag) str() string { + mut res := []string{} + res << '\n []Flag = [' + for f in af { + res << f.str() + } + res << ' ]' + return res.join('\n') +} + +// +pub struct FlagParser { +pub: + original_args []string // the original arguments to be parsed + idx_dashdash int // the index of a `--`, -1 if there is not any + all_after_dashdash []string // all options after `--` are ignored, and will be passed to the application unmodified +pub mut: + usage_examples []string // when set, --help will print: + // Usage: $appname $usage_examples[0]` + // or: $appname $usage_examples[1]` + // etc + default_help_label string = 'display this help and exit' + default_version_label string = 'output version information and exit' + args []string // the current list of processed args + max_free_args int + flags []Flag // registered flags + application_name string + application_version string + application_description string + min_free_args int + args_description string + allow_unknown_args bool // whether passing undescribed arguments is allowed + footers []string // when set, --help will display all the collected footers at the bottom. +} + +[unsafe] +fn (mut f FlagParser) free() { + unsafe { + for a in f.args { + a.free() + } + f.args.free() + // + for flag in f.flags { + flag.free() + } + f.flags.free() + // + f.application_name.free() + f.application_version.free() + f.application_description.free() + f.args_description.free() + } +} + +pub const ( + // used for formating usage message + space = ' ' + underline = '-----------------------------------------------' + max_args_number = 4048 +) + +// create a new flag set for parsing command line arguments +pub fn new_flag_parser(args []string) &FlagParser { + original_args := args.clone() + idx_dashdash := args.index('--') + mut all_before_dashdash := args.clone() + mut all_after_dashdash := []string{} + if idx_dashdash >= 0 { + all_before_dashdash.trim(idx_dashdash) + if idx_dashdash < original_args.len { + all_after_dashdash = original_args[idx_dashdash + 1..] + } + } + return &FlagParser{ + original_args: original_args + idx_dashdash: idx_dashdash + all_after_dashdash: all_after_dashdash + args: all_before_dashdash + max_free_args: flag.max_args_number + } +} + +// usage_example - add an usage example +// All examples will be listed in the help screen. +// If you do not give any examples, then a default usage +// will be shown, based on whether the application takes +// options and expects additional parameters. +pub fn (mut fs FlagParser) usage_example(example string) { + fs.usage_examples << example +} + +// add_footer - add a footnote, that will be shown +// at the bottom of the help screen. +pub fn (mut fs FlagParser) footer(footer string) { + fs.footers << footer +} + +// change the application name to be used in 'usage' output +pub fn (mut fs FlagParser) application(name string) { + fs.application_name = name +} + +// change the application version to be used in 'usage' output +pub fn (mut fs FlagParser) version(vers string) { + fs.application_version = vers +} + +// description appends to the application description lines, shown +// in the help/usage screen +pub fn (mut fs FlagParser) description(desc string) { + if fs.application_description.len == 0 { + fs.application_description = desc + } else { + fs.application_description += '\n$desc' + } +} + +// in most cases you do not need the first argv for flag parsing +pub fn (mut fs FlagParser) skip_executable() { + fs.args.delete(0) +} + +// allow_unknown_args - if your program has sub commands, that have +// their own arguments, you can call .allow_unknown_args(), so that +// the subcommand arguments (which generally are not known to your +// parent program), will not cause the validation in .finalize() to fail. +pub fn (mut fs FlagParser) allow_unknown_args() { + fs.allow_unknown_args = true +} + +// private helper to register a flag +fn (mut fs FlagParser) add_flag(name string, abbr byte, usage string, desc string) { + fs.flags << Flag{ + name: name + abbr: abbr + usage: usage + val_desc: desc + } +} + +// private: general parsing a single argument +// - search args for existence +// if true +// extract the defined value as string +// else +// return an (dummy) error -> argument is not defined +// +// - the name, usage are registered +// - found arguments and corresponding values are removed from args list +[manualfree] +fn (mut fs FlagParser) parse_value(longhand string, shorthand byte) []string { + full := '--$longhand' + defer { + unsafe { full.free() } + } + mut found_entries := []string{} + mut to_delete := []int{} + defer { + unsafe { to_delete.free() } + } + mut should_skip_one := false + for i, arg in fs.args { + if should_skip_one { + should_skip_one = false + continue + } + if arg.len == 0 || arg[0] != `-` { + continue + } + if (arg.len == 2 && arg[0] == `-` && arg[1] == shorthand) || arg == full { + if i + 1 >= fs.args.len { + return [] + } + nextarg := fs.args[i + 1] + if nextarg.len > 2 { + nextarg_rest := nextarg[..2] + if nextarg_rest == '--' { + // It could be end of input (--) or another argument (--abc). + // Both are invalid so die. + unsafe { nextarg_rest.free() } + return [] + } + unsafe { nextarg_rest.free() } + } + found_entries << fs.args[i + 1] + to_delete << i + to_delete << i + 1 + should_skip_one = true + continue + } + if arg.len > full.len + 1 && arg[..full.len + 1] == '$full=' { + found_entries << arg[full.len + 1..] + to_delete << i + continue + } + } + for i, del in to_delete { + // i entrys are deleted so it's shifted left i times. + fs.args.delete(del - i) + } + return found_entries +} + +// special parsing for bool values +// see also: parse_value +// +// special: it is allowed to define bool flags without value +// -> '--flag' is parsed as true +// -> '--flag' is equal to '--flag=true' +fn (mut fs FlagParser) parse_bool_value(longhand string, shorthand byte) ?string { + { + full := '--$longhand' + for i, arg in fs.args { + if arg.len == 0 { + continue + } + if arg[0] != `-` { + continue + } + if (arg.len == 2 && arg[0] == `-` && arg[1] == shorthand) || arg == full { + if fs.args.len > i + 1 && (fs.args[i + 1] in ['true', 'false']) { + val := fs.args[i + 1] + fs.args.delete(i + 1) + fs.args.delete(i) + return val + } else { + fs.args.delete(i) + return 'true' + } + } + if arg.len > full.len + 1 && arg[..full.len + 1] == '$full=' { + // Flag abc=true + val := arg[full.len + 1..] + fs.args.delete(i) + return val + } + if arg.len > 1 && arg[0] == `-` && arg[1] != `-` && arg.index_byte(shorthand) != -1 { + // -abc is equivalent to -a -b -c + return 'true' + } + } + } + return error("parameter '$longhand' not found") +} + +// bool_opt returns an optional that returns the value associated with the flag. +// In the situation that the flag was not provided, it returns null. +pub fn (mut fs FlagParser) bool_opt(name string, abbr byte, usage string) ?bool { + mut res := false + { + fs.add_flag(name, abbr, usage, '<bool>') + parsed := fs.parse_bool_value(name, abbr) or { + return error("parameter '$name' not provided") + } + res = parsed == 'true' + } + return res +} + +// defining and parsing a bool flag +// if defined +// the value is returned (true/false) +// else +// the default value is returned +// version with abbr +// TODO error handling for invalid string to bool conversion +pub fn (mut fs FlagParser) bool(name string, abbr byte, bdefault bool, usage string) bool { + value := fs.bool_opt(name, abbr, usage) or { return bdefault } + return value +} + +// int_multi returns all instances of values associated with the flags provided +// In the case that none were found, it returns an empty array. +pub fn (mut fs FlagParser) int_multi(name string, abbr byte, usage string) []int { + fs.add_flag(name, abbr, usage, '<multiple ints>') + parsed := fs.parse_value(name, abbr) + mut value := []int{} + for val in parsed { + value << val.int() + } + return value +} + +// int_opt returns an optional that returns the value associated with the flag. +// In the situation that the flag was not provided, it returns null. +pub fn (mut fs FlagParser) int_opt(name string, abbr byte, usage string) ?int { + mut res := 0 + { + fs.add_flag(name, abbr, usage, '<int>') + parsed := fs.parse_value(name, abbr) + if parsed.len == 0 { + return error("parameter '$name' not provided") + } + parsed0 := parsed[0] + res = parsed0.int() + } + return res +} + +// defining and parsing an int flag +// if defined +// the value is returned (int) +// else +// the default value is returned +// version with abbr +// TODO error handling for invalid string to int conversion +pub fn (mut fs FlagParser) int(name string, abbr byte, idefault int, usage string) int { + value := fs.int_opt(name, abbr, usage) or { return idefault } + return value +} + +// float_multi returns all instances of values associated with the flags provided +// In the case that none were found, it returns an empty array. +pub fn (mut fs FlagParser) float_multi(name string, abbr byte, usage string) []f64 { + fs.add_flag(name, abbr, usage, '<multiple floats>') + parsed := fs.parse_value(name, abbr) + mut value := []f64{} + for val in parsed { + value << val.f64() + } + return value +} + +// float_opt returns an optional that returns the value associated with the flag. +// In the situation that the flag was not provided, it returns null. +pub fn (mut fs FlagParser) float_opt(name string, abbr byte, usage string) ?f64 { + mut res := 0.0 + { + fs.add_flag(name, abbr, usage, '<float>') + parsed := fs.parse_value(name, abbr) + if parsed.len == 0 { + return error("parameter '$name' not provided") + } + res = parsed[0].f64() + } + return res +} + +// defining and parsing a float flag +// if defined +// the value is returned (float) +// else +// the default value is returned +// version with abbr +// TODO error handling for invalid string to float conversion +pub fn (mut fs FlagParser) float(name string, abbr byte, fdefault f64, usage string) f64 { + value := fs.float_opt(name, abbr, usage) or { return fdefault } + return value +} + +// string_multi returns all instances of values associated with the flags provided +// In the case that none were found, it returns an empty array. +pub fn (mut fs FlagParser) string_multi(name string, abbr byte, usage string) []string { + fs.add_flag(name, abbr, usage, '<multiple strings>') + return fs.parse_value(name, abbr) +} + +// string_opt returns an optional that returns the value associated with the flag. +// In the situation that the flag was not provided, it returns null. +pub fn (mut fs FlagParser) string_opt(name string, abbr byte, usage string) ?string { + mut res := '' + { + fs.add_flag(name, abbr, usage, '<string>') + parsed := fs.parse_value(name, abbr) + if parsed.len == 0 { + return error("parameter '$name' not provided") + } + res = parsed[0] + } + return res +} + +// defining and parsing a string flag +// if defined +// the value is returned (string) +// else +// the default value is returned +// version with abbr +pub fn (mut fs FlagParser) string(name string, abbr byte, sdefault string, usage string) string { + value := fs.string_opt(name, abbr, usage) or { return sdefault } + return value +} + +pub fn (mut fs FlagParser) limit_free_args_to_at_least(n int) { + if n > flag.max_args_number { + panic('flag.limit_free_args_to_at_least expect n to be smaller than $flag.max_args_number') + } + if n <= 0 { + panic('flag.limit_free_args_to_at_least expect n to be a positive number') + } + fs.min_free_args = n +} + +pub fn (mut fs FlagParser) limit_free_args_to_exactly(n int) { + if n > flag.max_args_number { + panic('flag.limit_free_args_to_exactly expect n to be smaller than $flag.max_args_number') + } + if n < 0 { + panic('flag.limit_free_args_to_exactly expect n to be a non negative number') + } + fs.min_free_args = n + fs.max_free_args = n +} + +// this will cause an error in finalize() if free args are out of range +// (min, ..., max) +pub fn (mut fs FlagParser) limit_free_args(min int, max int) { + if min > max { + panic('flag.limit_free_args expect min < max, got $min >= $max') + } + fs.min_free_args = min + fs.max_free_args = max +} + +pub fn (mut fs FlagParser) arguments_description(description string) { + fs.args_description = description +} + +// collect all given information and +pub fn (fs FlagParser) usage() string { + positive_min_arg := (fs.min_free_args > 0) + positive_max_arg := (fs.max_free_args > 0 && fs.max_free_args != flag.max_args_number) + no_arguments := (fs.min_free_args == 0 && fs.max_free_args == 0) + mut adesc := if fs.args_description.len > 0 { fs.args_description } else { '[ARGS]' } + if no_arguments { + adesc = '' + } + mut use := []string{} + if fs.application_version != '' { + use << '$fs.application_name $fs.application_version' + use << '$flag.underline' + } + if fs.usage_examples.len == 0 { + use << 'Usage: $fs.application_name [options] $adesc' + } else { + for i, example in fs.usage_examples { + if i == 0 { + use << 'Usage: $fs.application_name $example' + } else { + use << ' or: $fs.application_name $example' + } + } + } + use << '' + if fs.application_description != '' { + use << 'Description: $fs.application_description' + use << '' + } + // show a message about the [ARGS]: + if positive_min_arg || positive_max_arg || no_arguments { + if no_arguments { + use << 'This application does not expect any arguments' + use << '' + } else { + mut s := []string{} + if positive_min_arg { + s << 'at least $fs.min_free_args' + } + if positive_max_arg { + s << 'at most $fs.max_free_args' + } + if positive_min_arg && positive_max_arg && fs.min_free_args == fs.max_free_args { + s = ['exactly $fs.min_free_args'] + } + sargs := s.join(' and ') + use << 'The arguments should be $sargs in number.' + use << '' + } + } + if fs.flags.len > 0 { + use << 'Options:' + for f in fs.flags { + mut onames := []string{} + if f.abbr != 0 { + onames << '-$f.abbr.ascii_str()' + } + if f.name != '' { + if !f.val_desc.contains('<bool>') { + onames << '--$f.name $f.val_desc' + } else { + onames << '--$f.name' + } + } + option_names := ' ' + onames.join(', ') + mut xspace := '' + if option_names.len > flag.space.len - 2 { + xspace = '\n$flag.space' + } else { + xspace = flag.space[option_names.len..] + } + fdesc := '$option_names$xspace$f.usage' + use << fdesc + } + } + for footer in fs.footers { + use << footer + } + return use.join('\n').replace('- ,', ' ') +} + +fn (mut fs FlagParser) find_existing_flag(fname string) ?Flag { + for f in fs.flags { + if f.name == fname { + return f + } + } + return error('no such flag') +} + +fn (mut fs FlagParser) handle_builtin_options() { + mut show_version := false + mut show_help := false + fs.find_existing_flag('help') or { + show_help = fs.bool('help', `h`, false, fs.default_help_label) + } + fs.find_existing_flag('version') or { + show_version = fs.bool('version', 0, false, fs.default_version_label) + } + if show_help { + println(fs.usage()) + exit(0) + } + if show_version { + println('$fs.application_name $fs.application_version') + exit(0) + } +} + +// finalize - return all remaining arguments (non options). +// Call .finalize() after all arguments are defined. +// The remaining arguments are returned in the same order they are +// defined on the command line. If additional flags are found, i.e. +// (things starting with '--' or '-'), it returns an error. +pub fn (mut fs FlagParser) finalize() ?[]string { + fs.handle_builtin_options() + mut remaining := fs.args.clone() + if !fs.allow_unknown_args { + for a in remaining { + if (a.len >= 2 && a[..2] == '--') || (a.len == 2 && a[0] == `-`) { + return IError(&UnkownFlagError{ + msg: 'Unknown flag `$a`' + }) + } + } + } + if remaining.len < fs.min_free_args && fs.min_free_args > 0 { + return IError(&MinimumArgsCountError{ + msg: 'Expected at least $fs.min_free_args arguments, but given $remaining.len' + }) + } + if remaining.len > fs.max_free_args && fs.max_free_args > 0 { + return IError(&MaximumArgsCountError{ + msg: 'Expected at most $fs.max_free_args arguments, but given $remaining.len' + }) + } + if remaining.len > 0 && fs.max_free_args == 0 && fs.min_free_args == 0 { + return IError(&NoArgsExpectedError{ + msg: 'Expected no arguments, but given $remaining.len' + }) + } + remaining << fs.all_after_dashdash + return remaining +} + +// remaining_parameters will return all remaining parameters. +// Call .remaining_parameters() *AFTER* you have defined all options +// that your program needs. remaining_parameters will also print any +// parsing errors and stop the program. Use .finalize() instead, if +// you want more control over the error handling. +pub fn (mut fs FlagParser) remaining_parameters() []string { + return fs.finalize() or { + eprintln(err.msg) + println(fs.usage()) + exit(1) + } +} |