the makefile format

In standard makefiles, the commands that provide a recipe for creating or satisfying a target are prefixed with a TAB character. Comment lines are prefixed with a '#'. These very simplistic rules produce a standard makefile from an input file that contains makefile commands in a subset of the mediawiki text format.

getting started

The following cases arise:

mediawiki text annotations must be non-blank in column 1
empty lines - special treatment as an empty buffer generates null
indented by less than 4 spaces - treat as makefile text
indented by more than 4 spaces - treat as makefile command
already prefixed by a tab - treat as makefile command

Ideally, the annotation should go into the makefile as comments - this is easily done - but possibly the resulting long lines would need special handling - an exercise for the reader.

As an alternative to indentation, one could use a bracket convention - but that would require an understanding of the possible ways in which the chosen brackets might occur within the commands themselves, including the ways in which they be quoted or appear in escape sequences.

 .makefile()
   -                      skip              <- eof - ;
   '\n'                                     <- eof - generate           '\n' eot;          
   ' '   line :X                            <- eof - generate      X    '\n' eot;
   '\t'  var Text; spaces text              <- eof - generate '\t' Text '\n' eot;

rules to generate output

   generate output                          <- eof - ;

   - out                                    <- output -;
   eot                                      <- output;

detail

We have a line to be interpreted as significant in the makefile - decide if it is a command or something else. In either case, strip leading spaces, then prefix commands with a TAB.

   -       var Text; spaces text            <- line :Text;
   '    '  var Text; spaces text            <- line :{ '\t' Text };
   '\t'    var Text; spaces text            <- line :{ '\t' Text };

Grab everything up to the end of the line and put it into the variable called Text, which we are treating as the output buffer for this context:

   - (Text)                                 <- text - ;
   '\n'                                     <- text   ;
   eof                                      <- text - '\n' eof;

Skip everything up to the end of the line:

   - anything                               <- skip - ;
   '\n'                                     <- skip   ;
   eof                                      <- skip - '\n' eof;

Strip spaces, but treat an empty line as containing one space - again because empty buffers generate null (this is either a bug or a feature).

   '\n'                                     <- spaces ' \n';
   ' '                                      <- spaces - ;
   -                                        <- spaces;