//todo nullability
// type checking
// language consts (WORLD,SELF,SCRIPT)
// scope
/// <summary>
/// Parses a variable declaration
/// </summary>
/// <param name="at">position to start parsing in the ast</param>
/// <returns>Declaration node</returns>
private bool ParseVarDeclaration(ref int at)
{
DeclarationNode dNode = new DeclarationNode();
//at 0 is always Signature.TYPENAME
dNode.Variable.ValueNodeType = ValueNodeType.VARIABLE;
string declTypeName = Ast[at].Word;
at++;
if (Ast[at].Signature != Signature.IDENTIFIER)
{
return(false);
}
//Search tree for existing declaration
var varDecl = SeekVariableDeclarationWithName(Ast[at].Word, true);
if (varDecl != null)
{
_logger.LogFatal("Redeclaration of variable");
return(false);
}
dNode.Variable.VarName = Ast[at].Word;
at++;
if (Ast[at].Signature != Signature.OP_ASSIGN)
{
//not assignation case;
_logger.LogFatal("Variable declaration without assignation");
return(false);
}
//Right side value
at++;
switch (Ast[at].Signature)
{
case Signature.IDENTIFIER:
//Search tree for existing declaration
var r_varDecl = SeekVariableDeclarationWithName(Ast[at].Word);
if (r_varDecl == null)
{
_logger.LogFatal("No declaration of right side identifier");
goto default;
}
string varName = dNode.Variable.VarName;
dNode.Variable = r_varDecl.Variable;
dNode.Variable.VarName = varName;
break;
case Signature.I_CONST:
case Signature.F_CONST:
case Signature.STRINGLITTERAL:
dNode.Variable.ValueNodeType = ValueNodeType.CONSTLITERAL;
dNode.Variable.IsNull = false;
bool badTypeflag = false;
if (Ast[at].Signature == Signature.I_CONST)
{
if (int.TryParse(Ast[at].Word, out int intValue) &&
declTypeName == "int")
{
dNode.Variable.Value = intValue;
dNode.Variable.ValueType = TypesEnum.INT;
}
else
{
badTypeflag = true;
}
}
else if (Ast[at].Signature == Signature.F_CONST)
{
if (float.TryParse(Ast[at].Word, out float floatValue) &&
declTypeName == "float")
{
dNode.Variable.Value = floatValue;
dNode.Variable.ValueType = TypesEnum.FLOAT;
}
else
{
badTypeflag = true;
}
}
else /*STRINGLITTERAL*/ {
{
dNode.Variable.Value = Ast[at].Word;
dNode.Variable.ValueType = TypesEnum.STRING;
}
}
if (badTypeflag)
{
_logger.LogFatal("Mismatched type");
}
break;
case Signature.KW_TRUE:
case Signature.KW_FALSE:
dNode.Variable.ValueNodeType = ValueNodeType.CONSTLITERAL;
dNode.Variable.IsNull = false;
dNode.Variable.ValueType = TypesEnum.BOOL;
if (Ast[at].Signature == Signature.KW_TRUE)
{
dNode.Variable.Value = true;
}
else if (Ast[at].Signature == Signature.KW_FALSE)
{
dNode.Variable.Value = false;
}
break;
case Signature.CONST_SELF:
case Signature.CONST_WORLD:
case Signature.CONST_SCRIPT:
//Todo verify that the accessed const returns the valid type
dNode.Variable.ValueNodeType = ValueNodeType.VARIABLE;
dNode.Variable.IsNull = true;
break;
case Signature.KW_NULL:
dNode.Variable.ValueNodeType = ValueNodeType.CONSTLITERAL;
dNode.Variable.IsNull = true;
dNode.Variable.ValueType = TypesEnum.VOID;
dNode.Variable.Value = null;
break;
default:
return(false);
}
at++;
if (Ast[at].Signature != Signature.END)
{
return(false);
}
Tree.Current.AddChild(dNode);
//TODO not best way of doing that
Tree.VariableStack.Add(dNode);
//TODO check that we return a valid position in the AST
return(true);
}
private void ExtractTokens()
{
if (string.IsNullOrEmpty(Script))
{
Logger.LogFatal("Invalid Script file");
return;
}
if (!AreOpenCloseStatementsPaired())
{
return;
}
for (int i = 0; i < Script.Length; i++)
{
switch (Script[i])
{
case ' ':
case '\r':
case '\n':
case '\t':
break;
case '(':
Tokens.Add(new Token()
{
Signature = Signature.LPAREN
});
break;
case ')':
Tokens.Add(new Token()
{
Signature = Signature.RPAREN
});
break;
case '{':
Tokens.Add(new Token()
{
Signature = Signature.LBRACE
});
break;
case '}':
Tokens.Add(new Token()
{
Signature = Signature.RBRACE
});
break;
case '[':
Tokens.Add(new Token()
{
Signature = Signature.LBRACKET
});
break;
case ']':
Tokens.Add(new Token()
{
Signature = Signature.RBRACKET
});
break;
case ',':
Tokens.Add(new Token()
{
Signature = Signature.COMMA
});
break;
case '#':
Tokens.Add(new Token()
{
Signature = Signature.PREPROCESSOR
});
break;
case ';':
Tokens.Add(new Token()
{
Signature = Signature.END
});
break;
case '.':
Tokens.Add(new Token()
{
Signature = Signature.OP_DOT
});
break;
case '>':
if (Script[i + 1] == '=')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_GREATER_THAN_OR_EQUALS
});
i += 2;
}
else
{
Tokens.Add(new Token()
{
Signature = Signature.OP_GREATER_THAN
});
}
break;
case '<':
if (IsNextIndexValid(i))
{
if (Script[i + 1] == '=')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_LESS_THAN_OR_EQUALS
});
i += 2;
}
else
{
Tokens.Add(new Token()
{
Signature = Signature.OP_LESS_THAN
});
}
}
break;
case '/':
if (IsNextIndexValid(i))
{
switch (Script[i + 1])
{
case '=':
Tokens.Add(new Token()
{
Signature = Signature.OP_DIVIDE_ASSIGN
});
i += 1;
break;
default:
Tokens.Add(new Token()
{
Signature = Signature.OP_DIVIDE
});
break;
}
}
break;
case '*':
if (IsNextIndexValid(i))
{
switch (Script[i + 1])
{
case '=':
Tokens.Add(new Token()
{
Signature = Signature.OP_MUL_ASSIGN
});
i += 1;
break;
default:
Tokens.Add(new Token()
{
Signature = Signature.OP_MUL
});
break;
}
}
break;
case '+':
if (IsNextIndexValid(i))
{
switch (Script[i + 1])
{
case '+':
Tokens.Add(new Token()
{
Signature = Signature.OP_INCREMENT
});
i += 1;
break;
case '=':
Tokens.Add(new Token()
{
Signature = Signature.OP_PLUS_ASSIGN
});
i += 1;
break;
default:
Tokens.Add(new Token()
{
Signature = Signature.OP_PLUS
});
break;
}
}
break;
case '-':
if (IsNextIndexValid(i))
{
switch (Script[i + 1])
{
case '-':
Tokens.Add(new Token()
{
Signature = Signature.OP_DECREMENT
});
i += 1;
break;
case '=':
Tokens.Add(new Token()
{
Signature = Signature.OP_MINUS_ASSIGN
});
i += 1;
break;
default:
Tokens.Add(new Token()
{
Signature = Signature.OP_MINUS
});
break;
}
}
break;
case '=':
if (IsNextIndexValid(i))
{
if (Script[i + 1] == '=')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_EQUALS
});
i += 1;
if (IsNextIndexValid(i))
{
if (char.IsWhiteSpace(Script[i + 1]))
{
i += 1;
}
}
break;
}
else
{
Tokens.Add(new Token()
{
Signature = Signature.OP_ASSIGN
});
}
}
break;
case '!':
if (IsNextIndexValid(i))
{
if (Script[i + 1] == '=')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_NOTEQUALS
});
i += 1;
break;
}
else
{
Tokens.Add(new Token()
{
Signature = Signature.OP_NOT
});
}
}
break;
case '&':
if (IsNextIndexValid(i))
{
if (Script[i + 1] == '&')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_AND
});
Console.WriteLine("returns at: " + (i + 2) + " char: " + Script[i + 2]);
i += 1;
break;
}
else
{
Logger.LogFatal("Invalid symbol");
return;
}
}
break;
case '|':
if (IsNextIndexValid(i))
{
if (Script[i + 1] == '|')
{
Tokens.Add(new Token()
{
Signature = Signature.OP_OR
});
i += 1;
break;
}
else
{
Logger.LogFatal("Invalid symbol");
return;
}
}
break;
case '"':
var word = new StringBuilder();
for (int j = i + 1; j < Script.Length; j++)
{
if (Script[j] == '"')
{
i = j;
break;
}
else
{
word.Append(Script[j]);
}
}
Tokens.Add(new Token()
{
Word = word.ToString(),
Signature = Signature.STRINGLITTERAL
});
break;
default:
if (char.IsDigit(Script[i]))
{
int numberScanResult = ScanNumber(i);
if (numberScanResult >= Script.Length ||
numberScanResult == -1)
{
return;
}
else
{
i = numberScanResult;
}
}
else if (char.IsLetter(Script[i]))
{
int identifierScanResult = ScanIdentifier(i);
if (identifierScanResult >= Script.Length)
{
return;
}
else
{
i = identifierScanResult;
}
}
else
{
Logger.LogFatal("Illegal char: " + Script[i]);
return;
}
break;
}
}
}