protected virtual void CheckForIndentStyleMismatch(UString indent1, UString indent2, Token next)
{
int common = System.Math.Min(indent1.Length, indent2.Length);
indent1 = indent1.Substring(0, common);
indent2 = indent2.Substring(0, common);
if (!indent1.Equals(indent2))
{
ErrorSink.Write(Severity.Warning, IndexToMsgContext(next), "Indentation style changed on this line from {0} to {1}",
Les2Printer.PrintLiteral(indent1.ToString()),
Les2Printer.PrintLiteral(indent2.ToString()));
}
}
void GetPatternComponents(LNode pattern, out LNode varBinding, out bool refExistingVar, out LNode cmpExpr, out LNode isType, out LNode inRange, out VList <LNode> subPatterns, out VList <LNode> conditions)
{
// Here's a typical pattern (case expr):
// is Shape(ShapeType.Circle, ref size, Location: p is Point<int>(x, y)):
// When there is an arg list, we decode its Target and return the args.
//
// The caller is in charge of stripping out "Property:" prefix, if any,
// so the most complex pattern that this method considers is something
// like `(expr is Type in Range)(subPatterns) && conds` where `expr` is
// a varName or $varName to deconstruct, or some expression to test for
// equality. Assuming it's an equality test, the output will be
//
// varBinding = null
// refExistingVar = false
// cmpExpr = quote(expr);
// isType = quote(Type);
// inRange = quote(Range);
// conds will have "conds" pushed to the front.
//
bool haveSubPatterns = false;
subPatterns = VList <LNode> .Empty;
refExistingVar = pattern.AttrNamed(S.Ref) != null;
// First, look for "pattern && condition"
conditions = VList <LNode> .Empty;
while (pattern.Calls(S.And, 2))
{
conditions.Add(pattern.Args.Last);
pattern = pattern.Args[0];
}
LNode cmpExprOrBinding = null;
varBinding = cmpExpr = isType = inRange = null;
// Now decode the expression. Use three passes, each of which decodes
// an "outer" layer such as A is B, A in B, or expr(args). Since you
// can combine these operators, we may need multiple passes (e.g.
// "X is T in R" and "X in R is T" are equivalent), and keep in mind
// that operator trees like "A in B" are nearly identical to prefix-
// calls like "foo(A, B)" except for the call target and the `BaseStyle`.
for (int pass = 1; pass <= 3; pass++)
{
LNode inRange2 = inRange, isType2 = isType;
{
LNode patternL;
if (pattern.Calls(CodeSymbols.In, 2) && (patternL = pattern.Args[0]) != null && (inRange = pattern.Args[1]) != null || pattern.Calls((Symbol)"in", 2) && (patternL = pattern.Args[0]) != null && (inRange = pattern.Args[1]) != null)
{
pattern = patternL;
if (inRange2 != null)
{
_context.Sink.Error(inRange2, "match-case does not support multiple 'in' operators");
}
}
else if (pattern.Calls(CodeSymbols.Is, 2) && (cmpExprOrBinding = pattern.Args[0]) != null && (isType = pattern.Args[1]) != null || pattern.Calls((Symbol)"is", 2) && (cmpExprOrBinding = pattern.Args[0]) != null && (isType = pattern.Args[1]) != null)
{
pattern = cmpExprOrBinding;
if (isType2 != null)
{
_context.Sink.Error(isType2, "match-case does not support multiple 'is' operators");
}
}
else if (pattern.Calls(CodeSymbols.Is, 1) && (isType = pattern.Args[0]) != null || pattern.Calls((Symbol)"is", 1) && (isType = pattern.Args[0]) != null)
{
if (isType2 != null)
{
_context.Sink.Error(isType2, "match-case does not support multiple 'is' operators");
}
goto doneAnalysis;
}
else if (pattern.Calls(CodeSymbols.DotDotDot, 2) || pattern.Calls(CodeSymbols.DotDot, 2) || pattern.Calls(CodeSymbols.DotDotDot, 1) || pattern.Calls(CodeSymbols.DotDot, 1))
{
inRange = pattern;
goto doneAnalysis;
}
else if (pattern.Calls(CodeSymbols.Tuple))
{
subPatterns = pattern.Args;
cmpExprOrBinding = null;
}
else
{
// It's very tempting to detect NodeStyle.PrefixNotation to distinguish,
// say, A.B<C> from id(A, B, C), but I'm reluctant to do so. BaseStyle
// is by convention "unsemantic" and not guaranteed to be preserved
// across serializations or supported the same way by different parsers.
// So instead of asking "is this in PrefixNotation?" I ask "does the
// target appear to be a normal identifier?"
LNode target = pattern.Target;
if (!haveSubPatterns && pattern.IsCall && (!target.IsId || target.AttrNamed(S.TriviaInParens) != null || (!target.HasSpecialName && Les2Printer.IsNormalIdentifier(target.Name)))
)
{
haveSubPatterns = true;
subPatterns = pattern.Args;
pattern = pattern.Target;
}
else
{
cmpExprOrBinding = pattern;
}
}
}
}
doneAnalysis:
if (cmpExprOrBinding != null)
{
if (cmpExprOrBinding.Calls(S.Substitute, 1))
{
varBinding = cmpExprOrBinding[0];
}
else if (refExistingVar)
{
varBinding = cmpExprOrBinding;
}
else if ((varBinding ?? cmpExprOrBinding).IsIdNamed(__))
{
cmpExprOrBinding = varBinding = null;
}
// Originally a plain identifier would be a binding, like $identifier
//if (cmpExprOrBinding.IsId && cmpExprOrBinding.AttrNamed(S.TriviaInParens) == null)
// varBinding = cmpExprOrBinding;
if (varBinding != null)
{
if (varBinding.AttrNamed(S.Ref) != null)
{
refExistingVar = true;
varBinding = varBinding.WithoutAttrs();
}
if (!varBinding.IsId)
{
_context.Sink.Error(varBinding, "Invalid variable name in match-case: {0}", varBinding);
varBinding = null;
}
}
if (varBinding == null)
{
cmpExpr = cmpExprOrBinding;
}
}
if (refExistingVar && varBinding == null)
{
refExistingVar = false;
var got = cmpExprOrBinding ?? pattern;
_context.Sink.Warning(got, "'ref' expected a variable name (got `{0}`)", got);
}
}
