From 0e56fe29a9afeee00e02e722496678df89d37d50 Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Tue, 17 Nov 2009 13:59:39 +0200 Subject: Complete the implementation of the option documentation Add the man page generator. Port CLI usage, HTML documentation and the man page to the auto-generated version. Update examples and documentation. --- doc/guide/index.xhtml | 284 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 257 insertions(+), 27 deletions(-) (limited to 'doc/guide') diff --git a/doc/guide/index.xhtml b/doc/guide/index.xhtml index 24d76fa..a7ae6e7 100644 --- a/doc/guide/index.xhtml +++ b/doc/guide/index.xhtml @@ -125,6 +125,17 @@ padding : 0em 0 0em 0.7em; text-align : left; } + + /* Sample options documentation. */ + .options dt { + padding-top : 0.4em; + } + + .options dd { + padding-top : 0.1em; + padding-bottom : 0.4em; + padding-left : 1.4em; + } @@ -168,6 +179,7 @@ 2.2Translating CLI Definitions to C++ 2.3Implementing Application Logic 2.4Compiling and Running + 2.5Adding Documentation @@ -177,8 +189,9 @@ - - + + +
3.1Options Class Definition
3.2Option Definition
3.3Include Directive
3.4Namespace Definition
3.3Option Documentation
3.4Include Directive
3.5Namespace Definition
@@ -332,10 +345,9 @@ using namespace std; void usage () { - cerr << "usage: driver <options> <names>" << endl - << " [--help]" << endl - << " [--greeting <string>]" << endl - << " [--exclamations <integer>]" << endl; + cerr << "usage: driver [options] <names>" << endl + << "options:" << endl; + options::print_usage (cerr); } int @@ -411,19 +423,110 @@ Hi, Jane!!! 
 $ ./driver -n 3 Jane
 unknown option '-n'
-usage: driver <options> <names>
-  [--help]
-  [--greeting <string>]
-  [--exclamations <integer>]
+usage: driver [options] <names>
+options:
+--help
+--greeting <arg>
+--exclamations <arg>
 
 $ ./driver --exclamations abc Jane
 invalid value 'abc' for option '--exclamations'
-usage: driver <options> <names>
-  [--help]
-  [--greeting <string>]
-  [--exclamations <integer>]
+usage: driver [options] <names>
+options:
+--help
+--greeting <arg>
+--exclamations <arg>
+
+ +

2.5 Adding Documentation

+ +

As we have seen in the previous sections, the options + C++ class provides the print_usage() function which we + can use to display the application usage information. Right now this + information is very basic and does not include any description of + the purpose of each option:

+ + 
+$ ./driver --help
+usage: driver [options] <names>
+options:
+--help
+--greeting <arg>
+--exclamations <arg>
+
+ +

To make the usage information more descriptive we can document each + option in the command line interface definition. This information can + also be used to automatically generate program documentation in various + formats, such as HTML and man page. For example:

+ + 
+include <string>;
+
+class options
+{
+  bool --help {"Print usage information and exit."};
+
+  std::string --greeting = "Hello"
+  {
+    "<text>",
+    "Use <text> as a greeting phrase instead of the default \"Hello\"."
+  };
+
+  unsigned int --exclamations = 1
+  {
+    "<num>",
+    "Print <num> exclamation marks instead of 1 by default."
+  };
+};
+

If we now save this updated command line interface to + hello.cli and recompile our application, the usage + information printed by the program will look like this:

+ + 
+usage: driver [options] <names>
+options:
+--help               Print usage information and exit.
+--greeting <text>    Use <text> as a greeting phrase instead of the
+                     default "Hello".
+--exclamations <num> Print <num> exclamation marks instead of 1 by
+                     default.
+
+ +

We can also generate the program documentation in the HTML + (--generate-html CLI option) and man page + (--generate-man CLI option) formats. For example:

+ + 
+$ cli --generate-html hello.cli
+
+ +

The resulting hello.html file contains the following + documentation:

+ +
+
--help
+
Print usage information and exit.
+ +
--greeting text
+
Use text as a greeting phrase instead of the default "Hello".
+ +
--exclamations num
+
Print num exclamation marks instead of 1 by default.
+ +
+ +

This HTML fragment can be combined with custom prologue and epilogue + to create a complete program documentation + (--html-prologue/--html-epilogue options for the HTML + output, --man-prologue/--man-epilogue options for the + man page output). For an example of such complete documentation see + the CLI + Compiler Command Line Manual and the cli(1) man + page. For more information on the option documentation syntax, + see Section 3.3, Option Documentation.

@@ -431,8 +534,8 @@ usage: driver <options> <names>

3 CLI Language

This chapter describes the CLI language and its mapping to C++. - A CLI file consists of zero or more Include - Directives followed by one or more Namespace Definitions + A CLI file consists of zero or more Include + Directives followed by one or more Namespace Definitions or Option Class Definitions. C and C++-style comments can be used anywhere in the CLI file except in character and string literals.

@@ -488,6 +591,10 @@ public: operator= (const options&); public: + static void + print_usage (std::ostream&); + +public: bool help () const; @@ -500,7 +607,10 @@ public:

An option class is mapped to a C++ class with the same name. The C++ class defines a set of public overloaded constructors, a public copy constructor and an assignment operator, as well as a set of public - accessor functions corresponding to option definitions.

+ accessor functions corresponding to option definitions. It also + defines a public static print_usage() function that + can be used to print the usage information for the options + defined by the class.

The argc/argv arguments in the overloaded constructors are used to pass the command line arguments array, normally as passed @@ -654,12 +764,12 @@ namespace cli

3.2 Option Definition

-

An option definition consists of there components: type, - name, and default value. An option type can be any - C++ type as long as its string representation can be parsed using - the std::istream interface. If the option type is - user-defined then you will need to include its declaration using - the Include Directive.

+

An option definition consists of four components: type, + name, default value, and documentation. + An option type can be any C++ type as long as its string representation + can be parsed using the std::istream interface. If the option + type is user-defined then you will need to include its declaration using + the Include Directive.

An option of a type other than bool is expected to have a value. An option of type bool is treated as @@ -672,7 +782,7 @@ namespace cli by |. The C++ accessor function name is derived from the first name by removing any leading special characters, such as -, /, etc., and replacing special characters - in other places with underscore. For example, the following option + in other places with underscores. For example, the following option definition:

@@ -705,7 +815,7 @@ class options
 };
-

The final component of the option definition is the optional default +

The following component of the option definition is the optional default value. If the default value is not specified, then the option is initialized with the default constructor. In particular, this means that a bool option will be initialized to false, @@ -797,7 +907,127 @@ class options -m =B (key is an empty string), -m c= (value is an empty string), or -m d (same as -m d=).

-

3.3 Include Directive

+

The last component in the option definition is optional documentation. + It is discussed in the next section.

+ +

3.3 Option Documentation

+ +

Option documentation mimics C++ string array initialization: + it is enclosed in {} and consists of one or more + documentation strings separated by a comma, for example:

+ + 
+class options
+{
+  int --compression = 5
+  {
+    "<level>",
+    "Set compression to <level> instead of 5 by default.
+
+     With the higher compression levels the program may produce a
+     smaller output but may also take longer and use more memory."
+  };
+};
+
+ +

The option documentation consists of a maximum of three documentation + strings. The first string is the value documentation string. + It describes the option value and is only applicable to options + with types other than bool (options of type + bool are flags and don't have an explicit value). + The second string (or the first string for options of type + bool) is the short documentation string. It + provides a brief description of the option. The last entry + in the option documentation is the long documentation string. + It provides a detailed description of the option. The short + documentation string is optional. If only two strings are + present in the option documentation (one string for options + of type bool), then the second (first) string is + assumed to be the long documentation string.

+ +

Option documentation is used to print the usage information + as well as to generate program documentation in the HTML and + man page formats. For usage information the short documentation + string is used if provided. If only the long string is available, + then, by default, only the first sentence from the long string + is used. You can override this behavior and include the complete + long string in the usage information by specifying the + --long-usage CLI compiler option. When generating + the program documentation, the long documentation strings are + always used.

+ +

The value documentation string can contain text enclosed in + <> which is automatically recognized by the CLI + compiler and typeset according to the selected output in all three + documentation strings. For example, in usage the level + value for the --compression option presented above + will be displayed as <level> while in the HTML and + man page output it will be typeset in italic as + level. Here is another example using the + std::map type:

+ + 
+include <map>;
+include <string>;
+
+class options
+{
+  std::map<std::string, std::string> --map
+  {
+    "<key>=<value>",
+    "Add the <key>, <value> pair to the map."
+  };
+};
+
+ +

The resulting HTML output for this option would look like this:

+ +
+
--map key=value
+
Add the key, value pair to the map.
+
+ +

As you might have noticed from the examples presented so far, the + documentation strings can span multiple lines which is not possible + in C++. Also, all three documentation strings support the following + basic formatting mechanisms. The start of a new paragraph is indicated + by a blank line. A fragment of text can be typeset in monospace font + (normally used for code fragments) by enclosing it in the + \c{} block. Similarly, text can be typeset in bold or + italic fonts using the \b{} and \i{} blocks, + respectively. You can also combine several font properties in a single + block, for example, \cb{bold code}. If you need to include + literal } in a formatting block, you can use the + \} escape sequence, for example, + \c{int a[] = {1, 2\}}. The following example shows how we + can use these mechanisms:

+ + 
+class options
+{
+  int --compression = 5
+  {
+    "<level>",
+    "Set compression to <level> instead of 5 by default.
+
+     With the higher compression levels the program \i{may}
+     produce a smaller output but may also \b{take longer}
+     and \b{use more memory}."
+  };
+};
+
+ +

The resulting HTML output for this option would look like this:

+ +
+
--compression level
+
Set compression to level instead of 5 by default. + +

With the higher compression levels the program may produce a + smaller output but may also take longer and use more memory.

+
+ +

3.4 Include Directive

If you are using user-defined types in your option definitions, you will need to include their declarations with the include @@ -843,7 +1073,7 @@ class options and name_type types in the options class would be undeclared and result in compilation errors.

-

3.4 Namespace Definition

+

3.5 Namespace Definition

Option classes can be placed into namespaces which are translated directly to C++ namespaces. For example:

-- cgit v1.1