Allow overloading keywords with different signatures

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

diff --git a/source/loader.cpp b/source/loader.cpp
index 655514e5057c57a3c062317241abeeff5f9a08bb..6da8599ba550e373828ea96af9bd81942216180c 100644 (file)
--- a/source/loader.cpp
+++ b/source/loader.cpp
@@ -1,14 +1,53 @@
 /* $Id$
 
 This file is part of libmspdatafile
-Copyright © 2006-2008  Mikko Rasa, Mikkosoft Productions
+Copyright © 2006-2008, 2010  Mikko Rasa, Mikkosoft Productions
 Distributed under the LGPL
 */
 
+#include <msp/strings/formatter.h>
 #include "loader.h"
+#include "type.h"
 
 using namespace std;
 
+namespace {
+
+bool signature_match(char s, char a)
+{
+       if(s==a)
+               return true;
+       if(s==Msp::DataFile::IntType::signature && a==Msp::DataFile::FloatType::signature)
+               return true;
+       return false;
+}
+
+bool signature_match(const string &st_sig, const string &act_sig)
+{
+       if(act_sig=="*")
+               return true;
+       else if(act_sig.size()==2 && act_sig[1]=='*')
+       {
+               for(string::const_iterator i=st_sig.begin(); i!=st_sig.end(); ++i)
+                       if(*i!=act_sig[0])
+                               return false;
+
+               return true;
+       }
+       else if(st_sig.size()==act_sig.size())
+       {
+               for(unsigned i=0; i<st_sig.size(); ++i)
+                       if(!signature_match(st_sig[i], act_sig[i]))
+                               return false;
+
+               return true;
+       }
+       else
+               return false;
+}
+
+}
+
 namespace Msp {
 namespace DataFile {
 
@@ -39,22 +78,22 @@ void Loader::load(const Statement &st)
 void Loader::load_statement(const Statement &st)
 {
        cur_st = &st;
-       ActionMap::iterator j = actions.find(st.keyword);
-       if(j==actions.end())
-               throw_at(KeyError("Unknown keyword", st.keyword), st.get_location());
-       if(j->second)
+
+       try
+       {
+               LoaderAction *act = find_action(ActionKey(st.keyword, st.get_signature()));
+               if(act)
+                       act->execute(*this, st);
+       }
+       catch(Exception &e)
        {
-               try
-               {
-                       j->second->execute(*this, st);
-               }
-               catch(Exception &e)
-               {
-                       if(!e.where()[0])
-                               e.at(st.get_location());
-                       throw;
-               }
+               cur_st = 0;
+               if(!e.where()[0])
+                       e.at(st.get_location());
+
+               throw;
        }
+
        cur_st = 0;
 }
 
@@ -66,16 +105,45 @@ void Loader::load_sub_with(Loader &ldr)
        ldr.load(*cur_st);
 }
 
-void Loader::add(const string &k, LoaderAction *a)
+void Loader::add(const string &kwd, LoaderAction *act)
 {
-       ActionMap::iterator i = actions.find(k);
+       ActionKey key(kwd, act->get_signature());
+       ActionMap::iterator i = actions.find(key);
        if(i!=actions.end())
        {
                delete i->second;
-               i->second = a;
+               i->second = act;
        }
        else
-               actions[k] = a;
+               actions[key] = act;
+}
+
+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);
+
+       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));
+}
+
+
+Loader::ActionKey::ActionKey(const string &k, const string &s):
+       keyword(k),
+       signature(s)
+{ }
+
+bool Loader::ActionKey::operator<(const ActionKey &other) const
+{
+       if(keyword!=other.keyword)
+               return keyword<other.keyword;
+       return signature<other.signature;
 }
 
 } // namespace DataFile