9 The Metaprogramming System Libraries

The metaprogramming system consists of a number of fragments: astlevel, applgram, findgrammar, property, metagrammarcfl and metagramsemAtt:

• astlevel.bet contains the metaprogramming interface to the ASTs and fragments, as described above.
• applgram.bet contains one single pattern (subpattern of treelevel), which defines the proper initializations etc. for utilizing the treelevel interface for any given grammar.
• findgrammar.bet contains the grammarFinder used in the Mjølner BETA System (i.e. findgrammar seeks for grammars the places where the Mjølner BETA System locates its grammars).
• metagrammarcfl.bet contains the context-free level interface for the metagrammar, thus defining the interface to any grammar information, maintained by the Mjølner BETA System. metagrammarcfl is used by tools that needs to know about the structure of the grammar for the ASTs they are working on (e.g. the metaGrammarcfl interface is used by the Sif editor to find out about the valid derivations of a given nonterminal).
• metagramsematt.bet contains the semantic level interface for the metagrammar, and defines the interface to the available semantic information for grammars (e.g. options).