/// <summary>
/// Reads a prefix-expression from the input.
/// </summary>
/// <param name="input">Where to read input from.</param>
/// <param name="token">The token to append the total token onto.</param>
/// <returns>The expression that was read.</returns>
protected virtual IParseExp ReadPrefixExp(ITokenizer input, ref Token token)
{
Stack<UnaryInfo> ex = new Stack<UnaryInfo>();
IParseExp o = null;
Token last, debug = input.Peek();
debug.Value = "";
// check for unary operators
last = input.Peek();
while (last.Value == "-" || last.Value == "not" || last.Value == "#")
{
Read(input, ref debug);
if (last.Value == "-")
{
ex.Push(new UnaryInfo(1, last.StartPos, last.StartLine));
}
else if (last.Value == "not")
{
ex.Push(new UnaryInfo(2, last.StartPos, last.StartLine));
}
else
{
Contract.Assert(last.Value == "#");
ex.Push(new UnaryInfo(3, last.StartPos, last.StartLine));
}
last = input.Peek();
}
// check for literals
last = input.Peek();
int over = -1;
if (last.Value != null)
{
NumberFormatInfo ni = CultureInfo.CurrentCulture.NumberFormat;
if (last.Value != "..." && (char.IsNumber(last.Value, 0) || last.Value.StartsWith(ni.NumberDecimalSeparator, StringComparison.CurrentCulture)))
{
Read(input, ref debug); // read the number.
try
{
o = new LiteralItem(double.Parse(last.Value, CultureInfo.CurrentCulture)) { Debug = last };
}
catch (FormatException e)
{
throw new SyntaxException(Resources.BadNumberFormat, input.Name, last, e);
}
}
else if (last.Value.StartsWith("&", StringComparison.Ordinal))
{
Read(input, ref debug);
try
{
o = new LiteralItem(Convert.ToDouble(long.Parse(last.Value.Substring(1),
NumberStyles.AllowHexSpecifier, CultureInfo.CurrentCulture))) { Debug = last };
}
catch (FormatException e)
{
throw new SyntaxException(Resources.BadNumberFormat, input.Name, last, e);
}
}
else if (last.Value.StartsWith("\"", StringComparison.Ordinal))
{
Read(input, ref debug);
o = new LiteralItem(last.Value.Substring(1)) { Debug = last };
}
else if (last.Value.StartsWith("{", StringComparison.Ordinal))
{
o = ReadTable(input, ref debug);
}
else if (last.Value == "(")
{
Read(input, ref debug);
o = ReadExp(input, ref debug);
last = Read(input, ref debug);
if (last.Value != ")")
throw new SyntaxException(string.Format(Resources.TokenInvalidExpecting, last.Value, "expression", ")"),
input.Name, last);
}
else if (last.Value == "true")
{
Read(input, ref debug);
o = new LiteralItem(true) { Debug = last };
}
else if (last.Value == "false")
{
Read(input, ref debug);
o = new LiteralItem(false) { Debug = last };
}
else if (last.Value == "nil")
{
Read(input, ref debug);
o = new LiteralItem(null) { Debug = last };
}
else if (last.Value == "function")
{
o = ReadFunctionHelper(input, ref debug, false, false);
}
else
{
// allow for specifying overloads on global variables
if (last.Value.IndexOf('`') != -1)
{
if (!int.TryParse(last.Value.Substring(last.Value.IndexOf('`') + 1), out over))
throw new InvalidOperationException(Resources.OnlyNumbersInOverload);
last.Value = last.Value.Substring(0, last.Value.IndexOf('`'));
}
Read(input, ref debug);
o = new NameItem(last.Value) { Debug = last };
}
}
// read function calls and indexers
{
string inst = null;
bool cont = true;
while (cont)
{
last = input.Peek();
last.Value = last.Value ?? "";
if (last.Value == ".")
{
Read(input, ref debug);
if (over != -1)
throw new SyntaxException(Resources.FunctionCallAfterOverload, input.Name, last);
if (inst != null)
throw new SyntaxException(Resources.IndexerAfterInstance, input.Name, last);
last = Read(input, ref debug);
// allow for specifying an overload
if (last.Value.IndexOf('`') != -1)
{
if (!int.TryParse(last.Value.Substring(last.Value.IndexOf('`') + 1), out over))
throw new InvalidOperationException(Resources.OnlyNumbersInOverload);
last.Value = last.Value.Substring(0, last.Value.IndexOf('`'));
}
if (!IsName(last.Value))
throw new SyntaxException(string.Format(Resources.TokenNotAName, "indexer", last.Value),
input.Name, last);
if (!(o is IParsePrefixExp))
throw new SyntaxException(Resources.IndexAfterExpression, input.Name, last);
o = new IndexerItem(o, new LiteralItem(last.Value) { Debug = last }) { Debug = debug };
}
else if (last.Value == ":")
{
Read(input, ref debug);
if (over != -1)
throw new SyntaxException(Resources.FunctionCallAfterOverload, input.Name, last);
if (inst != null)
throw new SyntaxException(Resources.OneInstanceCall, input.Name, last);
inst = Read(input, ref debug).Value;
if (!IsName(inst))
throw new SyntaxException(string.Format(Resources.TokenNotAName, "indexer", last.Value),
input.Name, last);
}
else if (last.Value == "[")
{
Read(input, ref debug);
if (over != -1)
throw new SyntaxException(Resources.FunctionCallAfterOverload,
input.Name, last);
if (inst != null)
throw new SyntaxException(Resources.IndexerAfterInstance, input.Name, last);
var temp = ReadExp(input, ref debug);
last = Read(input, ref debug);
o = new IndexerItem(o, temp) { Debug = debug };
if (last.Value != "]")
throw new SyntaxException(
string.Format(Resources.TokenInvalidExpecting, last.Value, "indexer", "]"),
input.Name, last);
}
else if (last.Value.StartsWith("\"", StringComparison.Ordinal))
{
Read(input, ref debug);
FuncCallItem temp = new FuncCallItem(o, inst, over) { Debug = debug };
o = temp;
temp.AddItem(new LiteralItem(last.Value.Substring(1)), false);
inst = null;
over = -1;
}
else if (last.Value == "{")
{
var temp = ReadTable(input, ref debug);
FuncCallItem func = new FuncCallItem(o, inst, over) { Debug = debug };
o = func;
func.AddItem(temp, false);
inst = null;
over = -1;
}
else if (last.Value == "(")
{
Read(input, ref debug);
FuncCallItem func = new FuncCallItem(o, inst, over);
o = func;
inst = null;
over = -1;
while (input.Peek().Value != ")" && input.Peek().Value != null)
{
bool? byRef = null;
if (input.Peek().Value == "@")
{
byRef = false;
Read(input, ref debug);
}
else if (input.Peek().Value == "ref")
{
Read(input, ref debug);
if (input.Peek().Value == "(")
{
Read(input, ref debug);
byRef = true;
}
else
byRef = false;
}
var temp = ReadExp(input, ref debug);
if (byRef != null && !(temp is NameItem) && !(temp is IndexerItem))
throw new SyntaxException(Resources.OnlyVarByReference, input.Name, last);
if (temp == null)
throw new SyntaxException(string.Format(Resources.InvalidDefinition, "function call"),
input.Name, last);
func.AddItem(temp, byRef != null);
if (byRef == true && (last = input.Read()).Value != ")")
throw new SyntaxException(Resources.RefOneArgument,
input.Name, last);
if (input.Peek().Value == ",")
Read(input, ref debug);
else if (input.Peek().Value == ")")
break;
else
throw new SyntaxException(string.Format(Resources.TokenInvalidExpecting2, input.Peek().Value, "function call", ",", ")"), input.Name, last);
}
if (input.Peek() == null)
throw new SyntaxException(string.Format(Resources.UnexpectedEOF, "function call"),
input.Name, last);
Read(input, ref debug);
func.Debug = debug;
}
else
{
if (inst != null)
throw new SyntaxException(Resources.InstanceMissingArgs, input.Name, last);
if (over != -1)
throw new SyntaxException(Resources.OverloadMissingArgs, input.Name, last);
cont = false;
}
}
}
// read exponents
// HACK: This is needed here because the power operator has
// higher precedence than the unary operators. Rather than
// have unary operators handled in ReadExp, they are handled
// so exponents need to be handled before we apply the
// unary operators.
if (input.Peek().Value == "^")
{
Read(input, ref debug);
var temp = ReadPrefixExp(input, ref debug);
BinOpItem item = new BinOpItem(o, BinaryOperationType.Power, temp) { Debug = debug };
o = item;
}
// now apply the unary operators
while (ex.Count > 0)
{
var loc = ex.Pop();
Token tok = new Token(debug.Value, loc.StartPos, debug.EndPos, loc.StartLine, debug.EndLine);
switch (loc.Version)
{
case 1: // neg
if (o is LiteralItem)
{
object oo = (o as LiteralItem).Value;
if (!(oo is double))
throw new SyntaxException(Resources.InvalidUnary,
input.Name, debug);
o = new LiteralItem(-(double)oo) { Debug = tok };
}
else
o = new UnOpItem(o, UnaryOperationType.Minus) { Debug = tok };
break;
case 2: // not
o = new UnOpItem(o, UnaryOperationType.Not) { Debug = tok };
break;
case 3: // len
o = new UnOpItem(o, UnaryOperationType.Length) { Debug = tok };
break;
}
}
// finaly return
token.Append(debug);
return o;
}