public bool TryParse(
TokenReader reader,
out ProgramUnit result)
{
result = null;
Token tok = reader.Peek();
ProgramUnit programUnit = new ProgramUnit(tok);
if (tok.Is(Keyword.Namespace))
{
reader.Read();
string namespaceDecl = null;
if (!this.ParseFullNameDeclaration(reader, out namespaceDecl))
{
return false;
}
if (!this.Expect(reader, Keyword.SemiColon))
{
return false;
}
programUnit.Namespace = namespaceDecl;
}
tok = reader.Peek();
if (tok.Is(Keyword.Uses))
{
reader.Read();
string usesRef = null;
if (!this.ParseFullNameDeclaration(reader, out usesRef))
{
return false;
}
programUnit.AddUses(usesRef);
tok = reader.Peek();
while (tok.Is(Keyword.Comma))
{
reader.Read();
if (!this.ParseFullNameDeclaration(reader, out usesRef))
{
return false;
}
programUnit.AddUses(usesRef);
tok = reader.Peek();
}
if (!this.Expect(reader, Keyword.SemiColon))
{
return false;
}
}
tok = reader.Peek();
if (tok.Is(Keyword.Type))
{
if (!this.ParseTypeBlock(reader, programUnit))
{
return false;
}
}
tok = reader.Peek();
if (tok.Is(Keyword.Var))
{
VarBlock globalVars = null;
if (!this.ParseVarBlock(reader, true, out globalVars))
{
return false;
}
programUnit.Variables = globalVars;
}
tok = reader.Peek();
while (
tok.Is(Keyword.Function) ||
tok.Is(Keyword.Procedure) ||
tok.Is(Keyword.Constructor) ||
tok.Is(Keyword.Destructor))
{
MethodDefinition methodDef = null;
if (!this.ParseMethodDefinition(reader, out methodDef))
{
return false;
}
programUnit.AddMethod(methodDef);
if (!this.Expect(reader, Keyword.SemiColon))
{
return false;
}
tok = reader.Peek();
}
bool passed = ExpectEndOfFile(reader);
if (passed)
{
result = programUnit;
}
return passed;
}
