Stream based serialisation of AST nodes (can write arbitrarily large expressions without chewing memory).

git-svn-id: http://svn.drobilla.net/resp/tuplr@75 ad02d1e2-f140-0410-9f75-f8b11f17cedd

1 files changed, 55 insertions, 0 deletions

diff --git a/write.cpp b/write.cpp
new file mode 100644
index 0000000..b5784ab
--- /dev/null
+++ b/write.cpp
@@ -0,0 +1,55 @@
+/* Tuplr Serialisation
+ * Copyright (C) 2008-2009 David Robillard <dave@drobilla.net>
+ *
+ * Tuplr is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Affero General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * Tuplr is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Tuplr.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tuplr.hpp"
+
+ostream&
+operator<<(ostream& out, const AST* ast)
+{
+#define TRY_WRITE_LITERAL(T) \
+	const ASTLiteral<T>* lit ## T = dynamic_cast<const ASTLiteral<T>*>(ast); \
+	if (lit ## T) \
+		return out << (lit ## T)->val;
+
+	TRY_WRITE_LITERAL(int32_t);
+	TRY_WRITE_LITERAL(float);
+	TRY_WRITE_LITERAL(bool);
+
+	const ASTSymbol* sym = dynamic_cast<const ASTSymbol*>(ast);
+	if (sym)
+		return out << sym->cppstr;
+	
+	const AType* type = dynamic_cast<const AType*>(ast);
+	if (type) {
+		switch (type->kind) {
+		case AType::VAR:  return out << "?" << type->id;
+		case AType::PRIM: return out << type->at(0);
+		case AType::EXPR: break; // will catch Tuple case below
+		}
+	}
+	
+	const ASTTuple* tup = dynamic_cast<const ASTTuple*>(ast);
+	if (tup) {
+		out << "(";
+		for (size_t i = 0; i != tup->size(); ++i)
+			out << tup->at(i) << ((i != tup->size() - 1) ? " " : "");
+		return out << ")";
+	}
+	
+	return out << "?";
+}
+