Using the language server for a language

In order to highlight a language, the language server expects that the reader for the language returns a FileReader for the given file when the readFile function is called. This happens automatically if the FilePkgReader class is used to read the language. The language server then calls the createParser function of the FileReader to create a parser containing the syntax of the language. If it is enough to call the constructor of the parser, it is possible to override the rootRule function to only specify the root rule to use while parsing.

Reading a simple language can be implemented as follows: 

use lang:bs:macro; // for named{}

PkgReader reader(Url[] files, Package pkg) on Compiler {
    FilePkgReader(files, pkg, &createFile(FileInfo));
}

FileReader createFile(FileInfo info) on Compiler {
    FooFile(info);
}

class FooFile extends FileReader {
    init(FileInfo info) {
        init(info) {}
    }

    void readSyntaxRules() {}
    void readSyntaxProductions() {}
    void readTypes() {}
    void resolveTypes() {}
    void readFunctions() {}
    void resolveFunctions() {}

    // Either override this function...
    Rule rootRule() {
        named{SFile};
    }

    // ...or this function.
    InfoParser createParser() {
        InfoParser parser(named{SFile});
        // Add any additional syntax here.
        parser;
    }
}