/// <summary>
/// Determines if the specified variables ID refers to a read-only variable.
/// </summary>
/// <param name="varId">ID of the variable to check.</param>
/// <returns>If true, the variable is read-only.</returns>
internal bool IsReadOnly(int varId)
{
if (ByteCodes.IsGlobalVariable(varId))
{
return(Variables[ByteCodes.GetVariableIndex(varId)].CompilerFlags.HasFlag(CompilerFlag.ReadOnly));
}
return(false);
}
private void ParseVar(Token token)
{
// Get variable name
token = Lexer.GetNext();
if (token.Type != TokenType.Symbol)
{
Error(ErrorCode.ExpectedSymbol, token);
return;
}
// Check if variable already exists
int varId = GetVariableId(token.Value, false);
if (varId != -1)
{
Error(ErrorCode.VariableAlreadyDefined, token);
NextLine();
return;
}
if (InHeader)
{
// Create global variable
varId = GetVariableId(token.Value);
Debug.Assert(((ByteCodeVariableFlag)varId).HasFlag(ByteCodeVariableFlag.Global));
// Process any assignment
if (Lexer.PeekNext().Type == TokenType.Equal)
{
// Consume equal sign
Lexer.GetNext();
// Parse value (only literal value allowed here)
if (!ParseLiteral(out Variable variable))
{
return;
}
// Assign value to variable
Variables[ByteCodes.GetVariableIndex(varId)] = variable;
}
}
else
{
// Create local variable
varId = GetVariableId(token.Value);
// Process any assignment
if (Lexer.PeekNext().Type == TokenType.Equal)
{
// Consume equal sign
Lexer.GetNext();
Writer.Write(ByteCode.Assign, varId);
if (!ParseExpression())
{
return;
}
}
}
}
private Variable GetVariable(int varId)
{
if (ByteCodes.IsGlobalVariable(varId))
{
return(Variables[ByteCodes.GetVariableIndex(varId)]);
}
var context = GetFunctionContext();
if (ByteCodes.IsLocalVariable(varId))
{
return(context.Variables[ByteCodes.GetVariableIndex(varId)]);
}
// Function parameter
return(context.Parameters[ByteCodes.GetVariableIndex(varId)]);
}