public Context From(string source)
{
var stream = new ANTLRStringStream(source);
var lexer = new MessageContractsLexer(stream);
var tokens = new CommonTokenStream(lexer);
var parser = new MessageContractsParser(tokens);
var program = parser.GetProgram();
var commonTree = (CommonTree) program.Tree;
var node = commonTree as CommonErrorNode;
if (node != null)
{
throw new InvalidOperationException(node.ToString());
}
var ctx = new Context();
foreach (var child in commonTree.Children)
{
WalkDeclarations(child, ctx);
}
return ctx;
}