public IExpression Parse(Parser parser, Token token)
{
var condition = parser.ParseExpression(1);
var ifBlock = parser.ParseExpression(1);
if (ifBlock == null)
{
ErrorManager.CreateError("If statement is missing a body! ({ ... })", ErrorType.Error, token.Line, token.Column);
return(null);
}
var elseIfBlocks = new List <ElseIfExpression>();
if (parser.TokenStream.Peek().Type == TokenType.ELSEIF)
{
while (parser.TokenStream.Peek().Type == TokenType.ELSEIF)
{
var elseIfExpr = parser.ParseExpression(1);
elseIfBlocks.Add((ElseIfExpression)elseIfExpr);
}
}
ElseExpression elseExpr = null;
if (parser.TokenStream.Peek().Type == TokenType.ELSE)
{
elseExpr = parser.ParseExpression(1) as ElseExpression;
}
return(new IfExpression(token.Line, token.Column, (BlockExpression)ifBlock, condition, elseIfBlocks, elseExpr));
}
private ElseExpression ParseElseExpression()
{
var result = new ElseExpression();
_scanner.ReadNextToken();
ExpectTokenType(TokenType.PointyBracketClose);
result.Instructions = ParseInstructionsTillTagClose();
ExpectSequenceOfTokens(new TokenType[] { TokenType.TagClose, TokenType.Else, TokenType.PointyBracketClose });
return(result);
}
public override int GetHashCode()
{
unchecked
{
var hashCode = 10 + Condition.GetHashCode();
hashCode = (hashCode * 397) ^ ThenExpression.GetHashCode();
hashCode = (hashCode * 397) ^ ElseExpression.GetHashCode();
return(hashCode);
}
}
public static Result Run(ConditionalBlockExpression block, Scope scope)
{
foreach (BaseIfExpression if_expr in block.Ifs)
{
Result if_condition_result = Interpreters.Execute(if_expr.Condition, scope);
if (if_condition_result.IsTrue())
{
Result if_body_result = Interpreters.Execute(if_expr.Body, scope);
return(if_body_result);
}
}
ElseExpression else_expr = block.Else;
if (else_expr != null)
{
Result else_body_result = Interpreters.Execute(else_expr.Body, scope);
return(else_body_result);
}
return(Result.NULL);
}
private static ConditionalBlockExpression ToConditionalBlockExpression(IfStmt e)
{
ImmutableArray <BaseIfExpression> if_expr = ImmutableArray <BaseIfExpression> .Empty;
ElseExpression else_expr = null;
foreach (var c in e.Conditions)
{
if (c.Condition == null)
{
if (else_expr == null)
{
else_expr = ToElseExpression(c);
}
else
{
throw new ArgumentOutOfRangeException($"Multiple else expressions ???");
}
}
else
{
if (if_expr.Length == 0)
{
if_expr = if_expr.Add(ToIfExpression(c));
}
else
{
if_expr = if_expr.Add(ToElseIfExpression(c));
}
}
}
return(new ConditionalBlockExpression(
if_expr,
else_expr
));
}
private IfInstruction PopulateIfCondition(ScopePrototype scope, IfExpression ifExpression, ElseExpression elseExpression)
{
var ifInstruction = new IfInstruction(scope, ifExpression);
PopulateInstructions(ifExpression.Instructions, ifInstruction.IfBlock, scope);
if (elseExpression != null)
{
PopulateInstructions(elseExpression.Instructions, ifInstruction.ElseBlock, scope);
}
return(ifInstruction);
}
public ConditionalBlockExpression(ImmutableArray <BaseIfExpression> if_exprs, ElseExpression else_expr)
{
Ifs = if_exprs;
Else = else_expr;
}