Consider full statement signature when dealing with auxiliary loaders

[libs/datafile.git] / source / loader.cpp

diff --git a/source/loader.cpp b/source/loader.cpp
index 8111f54c94a26d9e7d61f195881aff607c67e418..bffa9fd31c6ccf5018535139aa119f859d3c36b0 100644 (file)
--- a/source/loader.cpp
+++ b/source/loader.cpp
@@ -1,4 +1,5 @@
-#include <msp/strings/formatter.h>
+#include <msp/strings/format.h>
+#include "dataerror.h"
 #include "loader.h"
 #include "type.h"
 
@@ -6,6 +7,16 @@ using namespace std;
 
 namespace {
 
+template<typename T>
+struct Set
+{
+       T &ref;
+       T orig;
+
+       Set(T &r, const T &v): ref(r), orig(r) { r = v; }
+       ~Set() { ref = orig; }
+};
+
 bool signature_match(char s, char a)
 {
        if(s==a)
@@ -41,18 +52,40 @@ bool signature_match(const string &st_sig, const string &act_sig)
 
 }
 
+
 namespace Msp {
 namespace DataFile {
 
+class unknown_keyword: public runtime_error
+{
+public:
+       unknown_keyword(const std::string &k):
+               runtime_error(k)
+       { }
+
+       virtual ~unknown_keyword() throw() { }
+};
+
+
+class invalid_signature: public runtime_error
+{
+public:
+       invalid_signature(const std::string &k, const std::string &s):
+               runtime_error(format("%s %s", k, s))
+       { }
+
+       virtual ~invalid_signature() throw() { }
+};
+
+
 Loader::Loader():
        cur_st(0),
-       allow_pointer_reload(true),
        check_sub_loads(false)
 { }
 
 Loader::~Loader()
 {
-       for(ActionMap::iterator i = actions.begin(); i!=actions.end(); ++i)
+       for(ActionMap::iterator i=actions.begin(); i!=actions.end(); ++i)
                delete i->second;
 }
 
@@ -69,42 +102,49 @@ void Loader::load(Parser &p)
 
 void Loader::load(const Statement &st)
 {
-       for(list<Statement>::const_iterator i = st.sub.begin(); i!=st.sub.end(); ++i)
+       for(list<Statement>::const_iterator i=st.sub.begin(); i!=st.sub.end(); ++i)
                load_statement(*i);
        finish();
 }
 
 void Loader::load_statement(const Statement &st)
 {
-       cur_st = &st;
+       Set<const Statement *> set_cst(cur_st, &st);
 
        try
        {
-               LoaderAction *act = find_action(ActionKey(st.keyword, st.get_signature()));
+               ActionKey key(st.keyword, st.get_signature());
+
+               if(!aux_loaders.empty() && !has_action(key))
+               {
+                       for(list<Loader *>::const_iterator i=aux_loaders.begin(); i!=aux_loaders.end(); ++i)
+                               if((*i)->has_action(key))
+                                       return (*i)->load_statement(st);
+               }
+
+               LoaderAction *act = find_action(key);
                if(act)
                {
                        sub_loaded = false;
                        act->execute(*this, st);
                        if(check_sub_loads && !st.sub.empty() && !sub_loaded)
-                               throw Exception("Substatements were not loaded");
+                               throw logic_error("substatements ignored");
                }
        }
-       catch(Exception &e)
+       catch(const data_error &)
        {
-               cur_st = 0;
-               if(!e.where()[0])
-                       e.at(st.get_location());
-
                throw;
        }
-
-       cur_st = 0;
+       catch(const exception &e)
+       {
+               throw data_error(st.source, st.line, e);
+       }
 }
 
 void Loader::load_sub_with(Loader &ldr)
 {
        if(!cur_st)
-               throw InvalidState("load_sub called without current statement");
+               throw logic_error("no current statement");
 
        ldr.load(*cur_st);
        sub_loaded = true;
@@ -123,19 +163,40 @@ void Loader::add(const string &kwd, LoaderAction *act)
                actions[key] = act;
 }
 
+void Loader::add_auxiliary_loader(Loader &ldr)
+{
+       aux_loaders.push_back(&ldr);
+}
+
+bool Loader::has_action(const ActionKey &key) const
+{
+       ActionMap::const_iterator i = actions.lower_bound(ActionKey(key.keyword, string()));
+       for(; (i!=actions.end() && i->first.keyword==key.keyword); ++i)
+               if(signature_match(key.signature, i->first.signature))
+                       return true;
+       return false;
+}
+
 LoaderAction *Loader::find_action(const ActionKey &key) const
 {
        ActionMap::const_iterator begin = actions.lower_bound(ActionKey(key.keyword, string()));
        ActionMap::const_iterator end = actions.upper_bound(ActionKey(key.keyword, "~"));
 
        if(begin==end)
-               throw KeyError("Unknown keyword", key.keyword);
+               throw unknown_keyword(key.keyword);
 
        for(ActionMap::const_iterator i=begin; i!=end; ++i)
                if(signature_match(key.signature, i->first.signature))
                        return i->second;
 
-       throw KeyError(format("Keyword '%s' does not accept signature '%s'", key.keyword, key.signature));
+       throw invalid_signature(key.keyword, key.signature);
+}
+
+const string &Loader::get_source() const
+{
+       if(!cur_st)
+               throw logic_error("no current statement");
+       return cur_st->source;
 }