Tomb/HACKING

Style guidelines
===============

Indentation
-----------
Code must be indented using four spaces.
In vim, this can be accomplished using

	set shiftwidth=4
	set expandtab

Naming
------

global variables should be `$UPPERCASE`.

local variables should be `$lowercase`, best if it can be written without underscores.
If you feel the need to name a variable `$longdescriptionofwhatthisisusefulfor`,
then you're allowed to use underscores. But do you really need?

functions should be lowercase+underscores: `do_this()`


Reporting to the user
---------------------

There are some nifty messaging functions to use. They all come with
shortcuts that you can use during development or for temporary
messages. The long name is to be used for translatable strings.

They display formatted messages, using colors when available.

DEBUG=1 make the _verbose messages visible.
QUIET=1 suppresses all messages (but the _verbose messages if DEBUG=1).

Here is the deal:

Name (Shortcut)  Return    When to use
=================================================================================
_failure (die)   exit 1    You want to exit the program with a fatal error.
                           You may pass a different exit code as second argument.

_warning (no)              You want to inform the user about an error condition.

_message (say)             You want to tell the user about what's going on.
                           You can pass -n (shortcut: act) for inline messages.

_verbose (xxx)             You need to check the current state of the program.

_success (yes)             You want to tell the user about a successful result.

All messaging function take a single "message" argument.
_failure takes an exit code as an optional second argument.

Examples:

    _verbose "Showing translatable debug message"
         xxx "This is temporary debug"
    _message "The program is doing something"
    _message -n "Inline messages "
    echo "are useful"
    _success "All is fine"
    _warning "Something's wrong"
    _failure "Fatal error: exiting with default exit code 1"
    _message "This is not reached, nor the next 'die' command"
         die "I am Jack's dead corpse." 127

Will display something like:

    tomb [D] Showing translatable debug message
    tomb [D] This is temporary debug
    tomb  .  The program is doing something
    tomb  >  Inline messages are useful
    tomb (*) All is fine
    tomb [W] Something's wrong
    tomb [E] Fatal error: exiting with default exit code 1