/// <summary>
/// Creates a rule - metadata that allows invocation of a function on
/// </summary>
private void RuleDeclaration()
{
if (_EnclosingCompiler != null)
{
throw new CompilerException(Tokens.Peek(), "Rules must be globally scoped.");
}
Token triggerName = Tokens.Consume(IDENTIFIER, "Rule declarations must begin with a named trigger.");
List <RuleCondition> conditions = new List <RuleCondition>();
// rule conditions
while (!Tokens.Match(RIGHT_BRACKET))
{
Token contextVariableName = Tokens.Consume(IDENTIFIER, "Rule must contain list of comparison expressions (missing identifier).");
Token comparisonOperation = Tokens.Advance(); // we will check validity of this token after consuming the value
Token contextVariableValue = Tokens.Consume(NUMBER, "Rule must contain list of comparison expressions (missing value)");
switch (comparisonOperation.Type)
{
case BANG_EQUAL:
// conditions.Add(RuleCondition.ConditionNotEquals(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
throw new CompilerException(Tokens.Peek(), "Rule must contain list of comparison expressions (can't use != operator).");
case EQUAL:
case EQUAL_EQUAL:
conditions.Add(RuleCondition.ConditionEquals(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
break;
case GREATER:
conditions.Add(RuleCondition.ConditionGreaterThan(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
break;
case GREATER_EQUAL:
conditions.Add(RuleCondition.ConditionGreaterThanOrEqual(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
break;
case LESS:
conditions.Add(RuleCondition.ConditionLessThan(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
break;
case LESS_EQUAL:
conditions.Add(RuleCondition.ConditionLessThanOrEqual(contextVariableName.Lexeme, contextVariableValue.LiteralAsNumber));
break;
default:
throw new CompilerException(Tokens.Peek(), "Rule must contain list of comparison expressions (missing operator).");
}
}
if (Tokens.Peek().Type == FUNCTION && Tokens.Peek(1).Type == IDENTIFIER)
{
string functionName = Tokens.Peek(1).Lexeme;
_Rules.Add(new Rule(BitString.GetBitStr(triggerName.Lexeme), BitString.GetBitStr(functionName), conditions.ToArray()));
}
else
{
throw new CompilerException(Tokens.Peek(), "Rule declaration must be followed by function.");
}
}
