Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/class/Mono.Options/Documentation/en/examples/bundling.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using Mono.Options;
+
+class Test {
+	public static void Main (string[] args)
+	{
+		var show_help = false;
+		var macros = new Dictionary<string, string>();
+		bool create = false, extract = false, list = false;
+		string output = null, input = null;
+		string color  = null;
+
+		var p = new OptionSet () {
+			"Usage: bundling [OPTIONS]+",
+			"Demo program to show the effects of bundling options and their values",
+			"",
+			"gcc-like options:",
+			{ "D:", "Predefine a macro with an (optional) value.",
+				(m, v) => {
+					if (m == null)
+						throw new OptionException ("Missing macro name for option -D.", 
+								"-D");
+					macros.Add (m, v);
+				} },
+			{ "d={-->}{=>}", "Alternate macro syntax.", 
+				(m, v) => macros.Add (m, v) },
+			{ "o=", "Specify the output file", v => output = v },
+
+			"",
+			"tar-like options:",
+			{ "f=", "The input file",   v => input = v },
+			{ "x",  "Extract the file", v => extract = v != null },
+			{ "c",  "Create the file",  v => create = v != null },
+			{ "t",  "List the file",    v => list = v != null },
+
+			"",
+			"ls-like optional values:",
+			{ "color:", "control whether and when color is used", 
+				v => color = v },
+
+			"",
+			"other:",
+			{ "h|help",  "show this message and exit", 
+			  v => show_help = v != null },
+			// default
+			{ "<>",
+				v => Console.WriteLine ("def handler: color={0}; arg={1}", color, v)},
+		};
+
+		try {
+			p.Parse (args);
+		}
+		catch (OptionException e) {
+			Console.Write ("bundling: ");
+			Console.WriteLine (e.Message);
+			Console.WriteLine ("Try `greet --help' for more information.");
+			return;
+		}
+
+		if (show_help) {
+			p.WriteOptionDescriptions (Console.Out);
+			return;
+		}
+
+		Console.WriteLine ("Macros:");
+		foreach (var m in (from k in macros.Keys orderby k select k)) {
+			Console.WriteLine ("\t{0}={1}", m, macros [m] ?? "<null>");
+		}
+		Console.WriteLine ("Options:");
+		Console.WriteLine ("\t Input File: {0}", input);
+		Console.WriteLine ("\tOuptut File: {0}", output);
+		Console.WriteLine ("\t     Create: {0}", create);
+		Console.WriteLine ("\t    Extract: {0}", extract);
+		Console.WriteLine ("\t       List: {0}", list);
+		Console.WriteLine ("\t      Color: {0}", color ?? "<null>");
+	}
+}
+

mcs/class/Mono.Options/Documentation/en/examples/bundling.in

@@ -0,0 +1,13 @@
+mono Documentation/en/examples/bundling.exe --help
+
+mono Documentation/en/examples/bundling.exe -D
+
+mono Documentation/en/examples/bundling.exe -DA -DB=C "-dD-->E" "-dF=>G" -d "H=>I" -cf input --color -ooutput
+
+mono Documentation/en/examples/bundling.exe -cfv input
+
+mono Documentation/en/examples/bundling.exe -xctf input
+
+mono Documentation/en/examples/bundling.exe --color=auto -o output -finput
+
+mono Documentation/en/examples/bundling.exe --color=on A B --color=off C D

mcs/class/Mono.Options/Documentation/en/examples/bundling.txt

@@ -0,0 +1,84 @@
+$ mono bundling.exe --help
+Usage: bundling [OPTIONS]+
+Demo program to show the effects of bundling options and their values
+
+gcc-like options:
+  -D[=VALUE1:VALUE2]         Predefine a macro with an (optional) value.
+  -d=VALUE1-->VALUE2         Alternate macro syntax.
+  -o=VALUE                   Specify the output file
+
+tar-like options:
+  -f=VALUE                   The input file
+  -x                         Extract the file
+  -c                         Create the file
+  -t                         List the file
+
+ls-like optional values:
+      --color[=VALUE]        control whether and when color is used
+
+other:
+  -h, --help                 show this message and exit
+
+$ mono bundling.exe -D
+bundling: Missing macro name for option -D.
+Try `greet --help' for more information.
+
+$ mono bundling.exe -DA -DB=C "-dD-->E" "-dF=>G" -d "H=>I" -cf input --color -ooutput
+Macros:
+	A=<null>
+	B=C
+	D=E
+	F=G
+	H=I
+Options:
+	 Input File: input
+	Ouptut File: output
+	     Create: True
+	    Extract: False
+	       List: False
+	      Color: <null>
+
+$ mono bundling.exe -cfv input
+def handler: color=; arg=input
+Macros:
+Options:
+	 Input File: v
+	Ouptut File: 
+	     Create: True
+	    Extract: False
+	       List: False
+	      Color: <null>
+
+$ mono bundling.exe -xctf input
+Macros:
+Options:
+	 Input File: input
+	Ouptut File: 
+	     Create: True
+	    Extract: True
+	       List: True
+	      Color: <null>
+
+$ mono bundling.exe --color=auto -o output -finput
+Macros:
+Options:
+	 Input File: input
+	Ouptut File: output
+	     Create: False
+	    Extract: False
+	       List: False
+	      Color: auto
+
+$ mono bundling.exe --color=on A B --color=off C D
+def handler: color=on; arg=A
+def handler: color=on; arg=B
+def handler: color=off; arg=C
+def handler: color=off; arg=D
+Macros:
+Options:
+	 Input File: 
+	Ouptut File: 
+	     Create: False
+	    Extract: False
+	       List: False
+	      Color: off

mcs/class/Mono.Options/Documentation/en/examples/context.cs

@@ -0,0 +1,78 @@
+using System;
+using System.ComponentModel;
+using System.Globalization;
+using Mono.Options;
+
+class FooConverter : TypeConverter {
+	public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
+	{
+		if (sourceType == typeof (string))
+			return true;
+		return base.CanConvertFrom (context, sourceType);
+	}
+
+	public override object ConvertFrom (ITypeDescriptorContext context,
+			CultureInfo culture, object value)
+	{
+		string v = value as string;
+		if (v != null) {
+			switch (v) {
+				case "A": return Foo.A;
+				case "B": return Foo.B;
+			}
+		}
+
+		return base.ConvertFrom (context, culture, value);
+	}
+}
+
+[TypeConverter (typeof(FooConverter))]
+class Foo {
+	public static readonly Foo A = new Foo ("A");
+	public static readonly Foo B = new Foo ("B");
+	string s;
+	Foo (string s) { this.s = s; }
+	public override string ToString () {return s;}
+}
+
+class DemoOption<T> : Option {
+	Action<T> action;
+
+	public DemoOption (string prototype, Action<T> action)
+		: base (prototype, null)
+	{
+		this.action = action;
+	}
+
+	protected override void OnParseComplete (OptionContext c)
+	{
+		Console.WriteLine ("# Parsed {0}; Value={1}; Index={2}",
+				c.OptionName, c.OptionValues [0] ?? "<null>", c.OptionIndex);
+		action (Parse<T> (c.OptionValues [0], c));
+	}
+}
+
+class Test {
+	public static void Main (string[] args)
+	{
+		Foo    f = null;
+		int    n = -1;
+		string s = null;
+		OptionSet p = new OptionSet () {
+			new DemoOption<Foo>    ("f:", v => f = v),
+			new DemoOption<int>    ("n=", v => n = v),
+			new DemoOption<string> ("s:", v => s = v),
+		};
+		try {
+			p.Parse (args);
+		}
+		catch (OptionException e) {
+			Console.Write ("context: ");
+			Console.WriteLine (e.Message);
+			return;
+		}
+		Console.WriteLine ("f={0}", f == null ? "<null>" : f.ToString ());
+		Console.WriteLine ("n={0}", n);
+		Console.WriteLine ("s={0}", s ?? "<null>");
+	}
+}

mcs/class/Mono.Options/Documentation/en/examples/context.in

@@ -0,0 +1,13 @@
+mono Documentation/en/examples/context.exe -f
+
+mono Documentation/en/examples/context.exe -n
+
+mono Documentation/en/examples/context.exe -s
+
+mono Documentation/en/examples/context.exe -f=invalid
+
+mono Documentation/en/examples/context.exe -n invalid
+
+mono Documentation/en/examples/context.exe -s=
+
+mono Documentation/en/examples/context.exe -f=A --n=42 /s=fourty-two

mcs/class/Mono.Options/Documentation/en/examples/context.txt

@@ -0,0 +1,36 @@
+$ mono context.exe -f
+# Parsed -f; Value=<null>; Index=0
+f=<null>
+n=-1
+s=<null>
+
+$ mono context.exe -n
+context: Missing required value for option '-n'.
+
+$ mono context.exe -s
+# Parsed -s; Value=<null>; Index=0
+f=<null>
+n=-1
+s=<null>
+
+$ mono context.exe -f=invalid
+# Parsed -f; Value=invalid; Index=0
+context: Could not convert string `invalid' to type Foo for option `-f'.
+
+$ mono context.exe -n invalid
+# Parsed -n; Value=invalid; Index=1
+context: Could not convert string `invalid' to type Int32 for option `-n'.
+
+$ mono context.exe -s=
+# Parsed -s; Value=; Index=0
+f=<null>
+n=-1
+s=
+
+$ mono context.exe -f=A --n=42 /s=fourty-two
+# Parsed -f; Value=A; Index=0
+# Parsed --n; Value=42; Index=1
+# Parsed /s; Value=fourty-two; Index=2
+f=A
+n=42
+s=fourty-two

mcs/class/Mono.Options/Documentation/en/examples/greet.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using Mono.Options;
+
+class Test {
+	static int verbosity;
+
+	public static void Main (string[] args)
+	{
+		bool show_help = false;
+		List<string> names = new List<string> ();
+		int repeat = 1;
+
+		var p = new OptionSet () {
+			"Usage: greet [OPTIONS]+ message",
+			"Greet a list of individuals with an optional message.",
+			"If no message is specified, a generic greeting is used.",
+			"",
+			"Options:",
+			{ "n|name=", "the {NAME} of someone to greet.",
+			  v => names.Add (v) },
+			{ "r|repeat=", 
+				"the number of {TIMES} to repeat the greeting.\n" + 
+					"this must be an integer.",
+			  (int v) => repeat = v },
+			{ "v", "increase debug message verbosity",
+			  v => { if (v != null) ++verbosity; } },
+			{ "h|help",  "show this message and exit", 
+			  v => show_help = v != null },
+		};
+
+		List<string> extra;
+		try {
+			extra = p.Parse (args);
+		}
+		catch (OptionException e) {
+			Console.Write ("greet: ");
+			Console.WriteLine (e.Message);
+			Console.WriteLine ("Try `greet --help' for more information.");
+			return;
+		}
+
+		if (show_help) {
+			p.WriteOptionDescriptions (Console.Out);
+			return;
+		}
+
+		string message;
+		if (extra.Count > 0) {
+			message = string.Join (" ", extra.ToArray ());
+			Debug ("Using new message: {0}", message);
+		}
+		else {
+			message = "Hello {0}!";
+			Debug ("Using default message: {0}", message);
+		}
+
+		foreach (string name in names) {
+			for (int i = 0; i < repeat; ++i)
+				Console.WriteLine (message, name);
+		}
+	}
+
+	static void Debug (string format, params object[] args)
+	{
+		if (verbosity > 0) {
+			Console.Write ("# ");
+			Console.WriteLine (format, args);
+		}
+	}
+}
+

mcs/class/Mono.Options/Documentation/en/examples/greet.in

@@ -0,0 +1,9 @@
+mono Documentation/en/examples/greet.exe --help
+
+mono Documentation/en/examples/greet.exe -v- -n A -name=B --name=C /name D -nE
+
+mono Documentation/en/examples/greet.exe -v -n E custom greeting for: {0}
+
+mono Documentation/en/examples/greet.exe -r 3 -n A
+
+mono Documentation/en/examples/greet.exe -r not-an-int

mcs/class/Mono.Options/Documentation/en/examples/greet.txt

@@ -0,0 +1,31 @@
+$ mono greet.exe --help
+Usage: greet [OPTIONS]+ message
+Greet a list of individuals with an optional message.
+If no message is specified, a generic greeting is used.
+
+Options:
+  -n, --name=NAME            the NAME of someone to greet.
+  -r, --repeat=TIMES         the number of TIMES to repeat the greeting.
+                               this must be an integer.
+  -v                         increase debug message verbosity
+  -h, --help                 show this message and exit
+
+$ mono greet.exe -v- -n A -name=B --name=C /name D -nE
+Hello A!
+Hello B!
+Hello C!
+Hello D!
+Hello E!
+
+$ mono greet.exe -v -n E custom greeting for: {0}
+# Using new message: custom greeting for: {0}
+custom greeting for: E
+
+$ mono greet.exe -r 3 -n A
+Hello A!
+Hello A!
+Hello A!
+
+$ mono greet.exe -r not-an-int
+greet: Could not convert string `not-an-int' to type Int32 for option `-r'.
+Try `greet --help' for more information.

mcs/class/Mono.Options/Documentation/en/examples/localization-es.po

@@ -0,0 +1,86 @@
+# NDesk.Options localization example.
+# Copyright (C) 2008 Novell, Inc.
+# This file is distributed under the same license as the NDesk.Options package.
+# Jonathan Pryor  <jonpryor@vt.edu>, 2008
+#
+#, fuzzy
+msgid ""
+msgstr ""
+"Project-Id-Version: NDesk.Options localization demo 1.0\n"
+"Report-Msgid-Bugs-To: jonpryor@vt.edu\n"
+"POT-Creation-Date: 2008-01-19 13:59-0500\n"
+"PO-Revision-Date: 2008-01-19 02:43+EST\n"
+"Last-Translator: Google\n"
+"Language-Team: http://translate.google.com/translate_t?langpair=en|es\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+
+#: localization.cs:16
+msgid "with-unix"
+msgstr ""
+
+#: localization.cs:19
+msgid "with-hello"
+msgstr ""
+
+#: localization.cs:20
+msgid "hello:"
+msgstr ""
+
+#: localization.cs:21
+msgid "with-default"
+msgstr ""
+
+#: localization.cs:26
+msgid "localization"
+msgstr ""
+
+#: localization.cs:28
+msgid "locale"
+msgstr ""
+
+#: localization.cs:34
+msgid "h|?|help"
+msgstr ""
+
+#: localization.cs:34
+msgid "show this message and exit."
+msgstr "A mostrar este mensaje y salir."
+
+#: localization.cs:36
+msgid "v|verbose"
+msgstr ""
+
+#: localization.cs:36
+msgid "increase message verbosity."
+msgstr "Aumento mensaje verbosidad."
+
+#: localization.cs:38
+msgid "n="
+msgstr ""
+
+#: localization.cs:38
+msgid "must be an int"
+msgstr "Debe ser un int"
+
+#: localization.cs:40
+msgid "V|version"
+msgstr ""
+
+#: localization.cs:40
+msgid "output version information and exit."
+msgstr "Salida de información de versión y sale."
+
+#: localization.cs:47
+msgid "localization: "
+msgstr ""
+
+#: localization.cs:54
+msgid "NDesk.Options Localizer Demo 1.0"
+msgstr ""
+
+#: localization.cs:56
+#, csharp-format
+msgid "Message level: {0}"
+msgstr ""

mcs/class/Mono.Options/Documentation/en/examples/localization.cs

@@ -0,0 +1,63 @@
+// Localization with NDesk.Options.OptionSet.
+//
+// Compile as:
+//   gmcs -r:Mono.Posix.dll -r:NDesk.Options.dll code-localization.cs
+using System;
+using System.IO;
+using Mono.Options;
+using Mono.Unix;
+
+class LocalizationDemo {
+	public static void Main (string[] args)
+	{
+		bool with_gettext = false;
+		string useLocalizer = null;
+		var p = new OptionSet () {
+			{ "with-gettext", v => { useLocalizer = "gettext"; } },
+			{ "with-hello",   v => { useLocalizer = "hello"; } },
+			{ "with-default", v => { /* do nothing */ } },
+		};
+		p.Parse (args);
+
+		Converter<string, string> localizer = f => f;
+		switch (useLocalizer) {
+			case "gettext":
+				Catalog.Init ("localization", 
+						Path.Combine (AppDomain.CurrentDomain.BaseDirectory,
+							"locale"));
+				localizer = f => { return Catalog.GetString (f); };
+				break;
+			case "hello":
+				localizer = f => { return "hello:" + f; };;
+				break;
+		}
+
+		bool help = false;
+		int verbose = 0;
+		bool version = false;
+		p = new OptionSet (localizer) {
+			{ "h|?|help", "show this message and exit.", 
+				v => help = v != null },
+			{ "v|verbose", "increase message verbosity.",
+				v => { ++verbose; } },
+			{ "n=", "must be an int",
+				(int n) => { /* ignore */ } },
+			{ "V|version", "output version information and exit.",
+				v => version = v != null },
+		};
+		try {
+			p.Parse (args);
+		}
+		catch (OptionException e) {
+			Console.Write ("localization: ");
+			Console.WriteLine (e.Message);
+			return;
+		}
+		if (help)
+			p.WriteOptionDescriptions (Console.Out);
+		if (version)
+			Console.WriteLine ("NDesk.Options Localizer Demo 1.0");
+		if (verbose > 0)
+			Console.WriteLine ("Message level: {0}", verbose);
+	}
+}

mcs/class/Mono.Options/Documentation/en/examples/localization.in

@@ -0,0 +1,9 @@
+mono Documentation/en/examples/localization.exe --help --version
+
+LANGUAGE=es mono Documentation/en/examples/localization.exe --with-gettext --help --version
+
+mono Documentation/en/examples/localization.exe --with-hello --help --version
+
+mono Documentation/en/examples/localization.exe -n not-an-int
+
+mono Documentation/en/examples/localization.exe --with-hello -n not-an-int

mcs/class/Mono.Options/Documentation/en/examples/localization.txt

@@ -0,0 +1,26 @@
+$ mono localization.exe --help --version
+  -h, -?, --help             show this message and exit.
+  -v, --verbose              increase message verbosity.
+  -n=VALUE                   must be an int
+  -V, --version              output version information and exit.
+NDesk.Options Localizer Demo 1.0
+
+$ LANGUAGE=es mono localization.exe --with-gettext --help --version
+  -h, -?, --help             A mostrar este mensaje y salir.
+  -v, --verbose              Aumento mensaje verbosidad.
+  -n=VALUE                   Debe ser un int
+  -V, --version              Salida de información de versión y sale.
+NDesk.Options Localizer Demo 1.0
+
+$ mono localization.exe --with-hello --help --version
+  -h, -?, --help             hello:show this message and exit.
+  -v, --verbose              hello:increase message verbosity.
+  -nhello:=VALUE             hello:must be an int
+  -V, --version              hello:output version information and exit.
+NDesk.Options Localizer Demo 1.0
+
+$ mono localization.exe -n not-an-int
+localization: Could not convert string `not-an-int' to type Int32 for option `-n'.
+
+$ mono localization.exe --with-hello -n not-an-int
+localization: hello:Could not convert string `not-an-int' to type Int32 for option `-n'.

mcs/class/Mono.Options/Documentation/en/examples/subclass.cs

@@ -0,0 +1,135 @@
+// Case-Insensitive and Concatenating OptionSet
+using System;
+using System.Collections.Generic;
+using Mono.Options;
+
+class DemoOptionSet : OptionSet {
+	protected override void InsertItem (int index, Option item)
+	{
+		if (item.Prototype.ToLower () != item.Prototype)
+			throw new ArgumentException ("prototypes must be lower-case!");
+		base.InsertItem (index, item);
+	}
+
+	protected override OptionContext CreateOptionContext ()
+	{
+		return new OptionContext (this);
+	}
+
+	protected override bool Parse (string option, OptionContext c)
+	{
+		string f, n, s, v;
+		bool haveParts = GetOptionParts (option, out f, out n, out s, out v);
+		Option nextOption = null;
+		string newOption  = option;
+
+		if (haveParts) {
+			string nl = n.ToLower ();
+			nextOption = Contains (nl) ? this [nl] : null;
+			newOption = f + n.ToLower () + (v != null ? s + v : "");
+		}
+
+		if (c.Option != null) {
+			// Prevent --a --b
+			if (c.Option != null && haveParts) {
+				if (nextOption == null) {
+					// ignore
+				}
+				else 
+					throw new OptionException (
+						string.Format ("Found option `{0}' as value for option `{1}'.",
+							option, c.OptionName), c.OptionName);
+			}
+
+			// have a option w/ required value; try to concat values.
+			if (AppendValue (option, c)) {
+				if (!option.EndsWith ("\\") && 
+						c.Option.MaxValueCount == c.OptionValues.Count) {
+					c.Option.Invoke (c);
+				}
+				return true;
+			}
+			else
+				base.Parse (newOption, c);
+		}
+
+		if (!haveParts || v == null) {
+			// Not an option; let base handle as a non-option argument.
+			return base.Parse (newOption, c);
+		}
+
+		if (nextOption.OptionValueType != OptionValueType.None && 
+				v.EndsWith ("\\")) {
+			c.Option = nextOption;
+			c.OptionValues.Add (v);
+			c.OptionName = f + n;
+			return true;
+		}
+
+		return base.Parse (newOption, c);
+	}
+
+	private bool AppendValue (string value, OptionContext c)
+	{
+		bool added = false;
+		string[] seps = c.Option.GetValueSeparators ();
+		foreach (var o in seps.Length != 0
+				? value.Split (seps, StringSplitOptions.None)
+				: new string[]{value}) {
+			int idx = c.OptionValues.Count-1;
+			if (idx == -1 || !c.OptionValues [idx].EndsWith ("\\")) {
+				c.OptionValues.Add (o);
+				added = true;
+			}
+			else {
+				c.OptionValues [idx] += value;
+				added = true;
+			}
+		}
+		return added;
+	}
+}
+
+class Demo {
+	public static void Main (string[] args)
+	{
+		List<string> names = new List<string> ();
+		Dictionary<string,string> map = new Dictionary<string,string> ();
+		int repeat = 1;
+
+		OptionSet p = new DemoOptionSet () {
+			{ "n|name=",    v => names.Add (v) },
+			{ "r|repeat:",  (int v) => repeat = v },
+			{ "m|map=",     (k,v) => map.Add (k, v) },
+		};
+
+		List<string> extra;
+		try {
+			extra = p.Parse (args);
+		}
+		catch (OptionException e) {
+			Console.Write ("subclass: ");
+			Console.WriteLine (e.Message);
+			return;
+		}
+
+		string message;
+		if (extra.Count > 0) {
+			message = string.Join (" ", extra.ToArray ());
+		}
+		else {
+			message = "Hello {0}!";
+		}
+
+		foreach (string name in names) {
+			for (int i = 0; i < repeat; ++i)
+				Console.WriteLine (message, name);
+		}
+		List<string> keys = new List<string>(map.Keys);
+		keys.Sort ();
+		foreach (string key in keys) {
+			Console.WriteLine ("Key: {0}={1}", key, map [key]);
+		}
+	}
+}
+

mcs/class/Mono.Options/Documentation/en/examples/subclass.in

@@ -0,0 +1,9 @@
+mono Documentation/en/examples/subclass.exe -n A -Name=B --NAME=C /nAMe D
+
+mono Documentation/en/examples/subclass.exe --Repeat -name A
+
+mono Documentation/en/examples/subclass.exe -Name --Repeat 3
+
+mono Documentation/en/examples/subclass.exe --Map a b -mAp c=d /maP=e=f
+
+mono Documentation/en/examples/subclass.exe --map 'a\\' 'b\\' c 'd\\' 'e\\' f

mcs/class/Mono.Options/Documentation/en/examples/subclass.txt

@@ -0,0 +1,18 @@
+$ mono subclass.exe -n A -Name=B --NAME=C /nAMe D
+Hello A!
+Hello B!
+Hello C!
+Hello D!
+
+$ mono subclass.exe --Repeat -name A
+
+$ mono subclass.exe -Name --Repeat 3
+subclass: Found option `--Repeat' as value for option `-name'.
+
+$ mono subclass.exe --Map a b -mAp c=d /maP=e=f
+Key: a=b
+Key: c=d
+Key: e=f
+
+$ mono subclass.exe --map 'a\' 'b\' c 'd\' 'e\' f
+Key: a\b\c=d\e\f