[pre.h] Preprocessing Facility

contents

   This module, [pre], realises a simple text processor. It supports the
   usage of macros which will be expanded during processing - by the result
   of the corresponding special replacement functions.

   The following rules describes the source text format:

   Text :: Literal
        :: "&&"
        :: "&" MacroName "&"
        :: "&" "IF" FlagName "&" Text
          ["&" "ELSE" "&" Text]
           "&" "FI" "&"
        :: Text Text

   Literal   :: Each printable ASCII-character beside "&", additionally "\n" und "\f".
   MacroName :: (Literal-"&"-" "-"\n"-"\f")+ .
                Beside that the reserved words "IF","ELSE","FI" are not allowed.
   FlagName  :: like MacroName; MacroName and FlagName must be disjunct sets.

   Now the interpretation can be specified as follows:

   A literal identifies itself, i.e. will be taken as is.

   '&&' will be expanded to '&'.

   '&MacroName&' forces the call of the corresponding evaluation function to output
   the replacement text for the macro. The left border is the column with the first "&".

   With the IF-THEN-ELSE-FI construction conditional generation becomes possible.
   FlagName refers to the corresponding boolean evaluation function. On true the text
   after '&IF FlagName& will be processed, otherwise the optional '&ELSE&'-part.

   Internally the following generalisation of the grammar will be used:

   Text :: Literal
        :: "&&"
        :: "&" MacroName "&"
        :: "&" KeyWord [FlagName] "&"
        :: Text Text

void PRE_dfnMacro(c_string MacroName, void (* Macro)())

void PRE_dfnFlag(c_string FlagName, int (* Flag)())

void PRE_Process(c_string environ, c_string file, c_string ext, FILE *fileout)

void PRE_init(void)

void PRE_quit(void)

int PRE_tColumnNo(void)