//Compile conditional if-then-else operator
private void CompileConditionalOperator(ElaCondition s, LabelMap map, Hints hints)
{
AddLinePragma(s);
CompileExpression(s.Condition, map, Hints.Scope, s);
var falseLab = cw.DefineLabel();
cw.Emit(Op.Brfalse, falseLab);
//Both the True and False parts may be the tail expressions
//Also this whole operator can be used as a statement. Or can be compiled
//in a situation when some of the referenced names are not initialized (Lazy)
var left = (hints & Hints.Left) == Hints.Left ? Hints.Left : Hints.None;
var tail = (hints & Hints.Tail) == Hints.Tail ? Hints.Tail : Hints.None;
if (s.True != null)
CompileExpression(s.True, map, left | tail | Hints.Scope, s);
if (s.False != null)
{
var skipLabel = cw.DefineLabel();
cw.Emit(Op.Br, skipLabel);
cw.MarkLabel(falseLab);
CompileExpression(s.False, map, left | tail | Hints.Scope, s);
cw.MarkLabel(skipLabel);
cw.Emit(Op.Nop);
}
else
{
AddError(ElaCompilerError.ElseMissing, s.True);
AddHint(ElaCompilerHint.AddElse, s.True);
}
}
void LambdaGuard(out ElaExpression exp)
{
var ifExp = new ElaCondition(t);
exp = ifExp;
var cond = default(ElaExpression);
var trueExp = default(ElaExpression);
var falseExp = default(ElaExpression);
Expr(out cond);
ifExp.Condition = cond;
Expect(24);
Expr(out trueExp);
ifExp.True = trueExp;
Expect(23);
if (la.kind == 36) {
Get();
Expect(24);
Expr(out falseExp);
} else if (StartOf(3)) {
LambdaGuard(out falseExp);
} else SynErr(100);
ifExp.False = falseExp;
}
void IfExpr(out ElaExpression exp)
{
Expect(35);
var cond = new ElaCondition(t);
var cexp = default(ElaExpression);
exp = cond;
Expr(out cexp);
cond.Condition = cexp;
Expect(37);
Expr(out cexp);
cond.True = cexp;
ExpectWeak(36, 5);
Expr(out cexp);
cond.False = cexp;
}