Initial project import

tools/v/vlib/cli/flag.v

@@ -0,0 +1,294 @@
+module cli
+
+pub enum FlagType {
+	bool
+	int
+	float
+	string
+	// If flag can set multiple time, use array type
+	int_array
+	float_array
+	string_array
+}
+
+// Flag holds information for a command line flag.
+// (flags are also commonly referred to as "options" or "switches")
+// These are typically denoted in the shell by a short form `-f` and/or a long form `--flag`
+pub struct Flag {
+pub mut:
+	flag FlagType
+	// Name of flag
+	name string
+	// Like short option
+	abbrev string
+	// Description of flag
+	description string
+	// If the flag is added to this command and to all subcommands
+	global bool
+	// If flag is required
+	required bool
+	// Default value if no value provide by command line
+	default_value []string = []
+mut:
+	// Set true if flag found.
+	found bool
+	// Value of flag
+	value []string = []
+}
+
+// get_all_found returns an array of all `Flag`s found in the command parameters.
+pub fn (flags []Flag) get_all_found() []Flag {
+	return flags.filter(it.found)
+}
+
+// get_bool returns `true` if the flag is set.
+// get_bool returns an error if the `FlagType` is not boolean.
+pub fn (flag &Flag) get_bool() !bool {
+	if flag.flag != .bool {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `bool`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	return val.len > 0 && val[0] == 'true'
+}
+
+// get_bool returns `true` if the flag specified in `name` is set.
+// get_bool returns an error if the `FlagType` is not boolean.
+pub fn (flags []Flag) get_bool(name string) !bool {
+	flag := flags.get(name)!
+	return flag.get_bool()
+}
+
+// get_int returns the `int` value argument of the flag.
+// get_int returns an error if the `FlagType` is not integer.
+pub fn (flag &Flag) get_int() !int {
+	if flag.flag != .int {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `int`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return 0
+	} else {
+		return val[0].int()
+	}
+}
+
+// get_ints returns the array of `int` value argument of the flag specified in `name`.
+// get_ints returns an error if the `FlagType` is not integer.
+pub fn (flag &Flag) get_ints() ![]int {
+	if flag.flag != .int_array {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `int_array`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return []int{}
+	} else {
+		mut values := []int{}
+
+		for f in val {
+			values << f.int()
+		}
+
+		return values
+	}
+}
+
+// get_int returns the `int` value argument of the flag specified in `name`.
+// get_int returns an error if the `FlagType` is not integer.
+pub fn (flags []Flag) get_int(name string) !int {
+	flag := flags.get(name)!
+	return flag.get_int()
+}
+
+// get_ints returns the array of `int` value argument of the flag specified in `name`.
+// get_ints returns an error if the `FlagType` is not integer.
+pub fn (flags []Flag) get_ints(name string) ![]int {
+	flag := flags.get(name)!
+	return flag.get_ints()
+}
+
+// get_float returns the `f64` value argument of the flag.
+// get_float returns an error if the `FlagType` is not floating point.
+pub fn (flag &Flag) get_float() !f64 {
+	if flag.flag != .float {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `float`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return 0.0
+	} else {
+		return val[0].f64()
+	}
+}
+
+// get_floats returns the `f64` value argument of the flag.
+// get_floats returns an error if the `FlagType` is not floating point.
+pub fn (flag &Flag) get_floats() ![]f64 {
+	if flag.flag != .float_array {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `float_array`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return []f64{}
+	} else {
+		mut values := []f64{}
+
+		for f in val {
+			values << f.f64()
+		}
+
+		return values
+	}
+}
+
+// get_float returns the `f64` value argument of the flag specified in `name`.
+// get_float returns an error if the `FlagType` is not floating point.
+pub fn (flags []Flag) get_float(name string) !f64 {
+	flag := flags.get(name)!
+	return flag.get_float()
+}
+
+// get_floats returns the array of `f64` value argument of the flag specified in `name`.
+// get_floats returns an error if the `FlagType` is not floating point.
+pub fn (flags []Flag) get_floats(name string) ![]f64 {
+	flag := flags.get(name)!
+	return flag.get_floats()
+}
+
+// get_string returns the `string` value argument of the flag.
+// get_string returns an error if the `FlagType` is not string.
+pub fn (flag &Flag) get_string() !string {
+	if flag.flag != .string {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `string`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return ''
+	} else {
+		return val[0]
+	}
+}
+
+// get_strings returns the array of `string` value argument of the flag.
+// get_strings returns an error if the `FlagType` is not string.
+pub fn (flag &Flag) get_strings() ![]string {
+	if flag.flag != .string_array {
+		return error('${flag.name}: Invalid flag type `${flag.flag}`, expected `string_array`')
+	}
+
+	val := flag.get_value_or_default_value()
+
+	if val.len == 0 {
+		return []string{}
+	} else {
+		return val
+	}
+}
+
+// get_string returns the `string` value argument of the flag specified in `name`.
+// get_string returns an error if the `FlagType` is not string.
+pub fn (flags []Flag) get_string(name string) !string {
+	flag := flags.get(name)!
+	return flag.get_string()
+}
+
+// get_strings returns the `string` value argument of the flag specified in `name`.
+// get_strings returns an error if the `FlagType` is not string.
+pub fn (flags []Flag) get_strings(name string) ![]string {
+	flag := flags.get(name)!
+	return flag.get_strings()
+}
+
+// parse parses flag values from arguments and return an array of arguments with all consumed elements removed.
+pub fn (mut flag Flag) parse(args []string, posix_mode bool) ![]string {
+	return match true {
+		!flag.matches(args[0], posix_mode) {
+			args
+		}
+		flag.flag == .bool {
+			flag.parse_bool(args)!
+		}
+		flag.value.len > 0 && flag.flag !in [.int_array, .float_array, .string_array] {
+			error('The argument `${flag.name}` accept only one value!')
+		}
+		else {
+			flag.parse_raw(args)!
+		}
+	}
+}
+
+// matches returns `true` if first arg in `args` matches this flag.
+fn (mut flag Flag) matches(arg string, posix_mode bool) bool {
+	prefix := if posix_mode { '--' } else { '-' }
+	return (flag.name != '' && arg == '${prefix}${flag.name}')
+		|| (flag.name != '' && arg.starts_with('${prefix}${flag.name}='))
+		|| (flag.abbrev != '' && arg == '-${flag.abbrev}')
+		|| (flag.abbrev != '' && arg.starts_with('-${flag.abbrev}='))
+}
+
+fn (mut flag Flag) parse_raw(args []string) ![]string {
+	if args[0].len > flag.name.len && args[0].contains('=') {
+		flag.value << args[0].split('=')[1]
+		return args[1..]
+	} else if args.len >= 2 {
+		flag.value << args[1]
+		return args[2..]
+	}
+	return error('Missing argument for `${flag.name}`')
+}
+
+fn (mut flag Flag) parse_bool(args []string) ![]string {
+	if args[0].len > flag.name.len && args[0].contains('=') {
+		flag.value = [args[0].split('=')[1]]
+		return args[1..]
+	} else if args.len >= 2 {
+		if args[1] in ['true', 'false'] {
+			flag.value = [args[1]]
+			return args[2..]
+		}
+	}
+	// In fact bool cannot be multiple
+	flag.value = ['true']
+	return args[1..]
+}
+
+// get returns the `Flag` matching `name` or an error
+// if it can't be found.
+fn (flags []Flag) get(name string) !Flag {
+	for flag in flags {
+		if flag.name == name {
+			return flag
+		}
+	}
+	return error('Flag `${name}` not found in ${flags}')
+}
+
+fn (flags []Flag) contains(name string) bool {
+	for flag in flags {
+		if flag.name == name || flag.abbrev == name {
+			return true
+		}
+	}
+	return false
+}
+
+// Check if value is set by command line option. If not, return default value.
+fn (flag &Flag) get_value_or_default_value() []string {
+	if flag.value.len == 0 && flag.default_value.len > 0 {
+		// If default value is set and no value provide, use default value.
+		return flag.default_value
+	} else {
+		return flag.value
+	}
+}