1 2 sparse (spärs), adj,., spars-er, spars-est. 3 1. thinly scattered or distributed; "a sparse population" 4 2. thin; not thick or dense: "sparse hair" 5 3. scanty; meager. 6 4. semantic parse 7 [ from Latin: spars(us) scattered, past participle of 8 spargere 'to sparge' ] 9 10 Antonym: abundant 11 12Sparse is a semantic parser of source files: it's neither a compiler 13(although it could be used as a front-end for one) nor is it a 14preprocessor (although it contains as a part of it a preprocessing 15phase). 16 17It is meant to be a small - and simple - library. Scanty and meager, 18and partly because of that easy to use. It has one mission in life: 19create a semantic parse tree for some arbitrary user for further 20analysis. It's not a tokenizer, nor is it some generic context-free 21parser. In fact, context (semantics) is what it's all about - figuring 22out not just what the grouping of tokens are, but what the _types_ are 23that the grouping implies. 24 25And no, it doesn't use lex and yacc (or flex and bison). In my personal 26opinion, the result of using lex/yacc tends to end up just having to 27fight the assumptions the tools make. 28 29The parsing is done in five phases: 30 31 - full-file tokenization 32 - pre-processing (which can cause another tokenization phase of another 33 file) 34 - semantic parsing. 35 - lazy type evaluation 36 - inline function expansion and tree simplification 37 38Note the "full file" part. Partly for efficiency, but mostly for ease of 39use, there are no "partial results". The library completely parses one 40whole source file, and builds up the _complete_ parse tree in memory. 41 42Also note the "lazy" in the type evaluation. The semantic parsing 43itself will know which symbols are typedefines (required for parsing C 44correctly), but it will not have calculated what the details of the 45different types are. That will be done only on demand, as the back-end 46requires the information. 47 48This means that a user of the library will literally just need to do 49 50 struct string_list *filelist = NULL; 51 char *file; 52 53 action(sparse_initialize(argc, argv, filelist)); 54 55 FOR_EACH_PTR_NOTAG(filelist, file) { 56 action(sparse(file)); 57 } END_FOR_EACH_PTR_NOTAG(file); 58 59and he is now done - having a full C parse of the file he opened. The 60library doesn't need any more setup, and once done does not impose any 61more requirements. The user is free to do whatever he wants with the 62parse tree that got built up, and needs not worry about the library ever 63again. There is no extra state, there are no parser callbacks, there is 64only the parse tree that is described by the header files. The action 65funtion takes a pointer to a symbol_list and does whatever it likes with it. 66 67The library also contains (as an example user) a few clients that do the 68preprocessing, parsing and type evaluation and just print out the 69results. These clients were done to verify and debug the library, and 70also as trivial examples of what you can do with the parse tree once it 71is formed, so that users can see how the tree is organized. 72