hack.py

@sender("arcadia")
def arcadia_sender(repl, text, view):
    # call (load-string) instead of just writing the string so
    # that syntax errors are caught and thrown back immediately
    text = '(load-string "' + text.strip().replace('"', r'\"') + '")'

    # find the first non-commented statement from the start of the file
    namespacedecl = view.find(r"^[^;]*?\(", 0)

    # if it's a namespace declaration, go search for the namespace name
    if namespacedecl and view.scope_name(namespacedecl.end()-1).startswith("source.arcadia meta.function.namespace.clojure"):
        namespacedecl = view.extract_scope(namespacedecl.end()-1)

        # we're looking for the first symbol within the declaration that
        # looks like a namespace and isn't metadata, a comment, etc.
        pos = namespacedecl.begin() + 3
        while pos < namespacedecl.end():
            # see http://clojure.org/reader for a description of valid
            # namespace names. the inital } or whitespace make sure we're
            # not matching on keywords etc.
            namespace = view.find(r"[\}\s][A-Za-z\_!\?\*\+\-][\w!\?\*\+\-:]*(\.[\w!\?\*\+\-:]+)*", pos)

            if not namespace:
                # couldn't find the namespace name within the declaration. suspicious.
                break
            elif view.scope_name(namespace.begin() + 1).startswith("source.arcadia meta.function.namespace.clojure entity.name.namespace.clojure"):
                # looks alright, we've got our namespace!
                # switch to namespace before executing command

                # we could do this explicitly by calling (ns), (in-ns) etc:
                # text = "(ns " + view.substr(namespace)[1:] + ") " + text
                # but this would not only result in an extra return value
                # printed to the user, the repl would also remain in that
                # namespace after execution, so instead we do the same thing
                # that swank-clojure does:
                text = "(binding [*ns* (or (find-ns '" + view.substr(namespace)[1:] + ") (find-ns 'user))] " + text + ')'
                # i.e. we temporarily switch to the namespace if it has already
                # been created, otherwise we execute it in 'user. the most
                # elegant option for this would probably be:
                # text = "(binding [*ns* (create-ns '" + view.substr(namespace)[1:] + ")] " + text + ')'
                # but this can lead to problems because of newly created
                # namespaces not automatically referring to clojure.core
                # (see https://groups.google.com/forum/?fromgroups=#!topic/clojure/Th-Bqq68hfo)
                break
            else:
                # false alarm (metadata or a comment), keep looking
                pos = namespace.end()
    return default_sender(repl, text + repl.cmd_postfix, view)