/// <summary>Given the contents of case statement like `matchCode` or
/// `switch`, this method gets a list of the cases.</summary>
/// <returns>The first item in each pair is a list of the cases associated
/// with a single handler (for `default:`, the list is empty). The second
/// item is the handler code.</returns>
static internal VList <Pair <VList <LNode>, VList <LNode> > > GetCases(VList <LNode> body, IMessageSink sink)
{
var pairs = VList <Pair <VList <LNode>, VList <LNode> > > .Empty;
for (int i = 0; i < body.Count; i++)
{
bool isDefault;
if (body[i].Calls(S.Lambda, 2))
{
var alts = body[i][0].WithoutOuterParens().AsList(S.Tuple).SmartSelect(AutoStripBraces);
pairs.Add(Pair.Create(alts, body[i][1].AsList(S.Braces)));
}
else
if ((isDefault = IsDefaultLabel(body[i])) || body[i].CallsMin(S.Case, 1))
{
var alts = isDefault ? VList <LNode> .Empty : body[i].Args.SmartSelect(AutoStripBraces);
int bodyStart = ++i;
for (; i < body.Count && !IsDefaultLabel(body[i]) && !body[i].CallsMin(S.Case, 1); i++)
{
}
var handler = new VList <LNode>(body.Slice(bodyStart, i - bodyStart));
pairs.Add(Pair.Create(alts, handler));
i--; // counteract i++ when loop repeats (redo)
}
else
{
Reject(sink, body[i], "expected 'case _:' or '_ => _'");
break;
}
}
return(pairs);
}
static bool CaptureGroup(ref int c, ref int p, VList <LNode> cArgs, VList <LNode> pArgs, ref MMap <Symbol, LNode> captures, ref VList <LNode> attrs)
{
Debug.Assert(IsParamsCapture(pArgs[p]));
// The goal now is to find a sequence of nodes in cArgs that matches
// the sequence pArgs[p+1 .. p+x] where x is the maximum value such
// that none of the nodes in the sequence are $(params caps).
int saved_p = p, saved_c = c;
var savedCaptures = captures.AsImmutable();
var savedAttrs = attrs;
int captureSize = 0;
for (;; captureSize++)
{
for (p++, c += captureSize; ; c++, p++)
{
// If we run out of pArgs, great, we're done; if we run out
// of cArgs, the match fails, unless all remaining pArgs are
// $(params caps).
if (p >= pArgs.Count || IsParamsCapture(pArgs[p]))
{
goto done_group;
}
else
{
if (c >= cArgs.Count)
{
return(false);
}
if (!MatchesPatternNested(cArgs[c], pArgs[p], ref captures, ref attrs))
{
goto continue_group;
}
}
}
continue_group :;
p = saved_p;
c = saved_c;
attrs = savedAttrs;
captures = savedCaptures.AsMutable();
}
done_group:
AddCapture(captures, pArgs[saved_p], cArgs.Slice(saved_c, captureSize));
return(true);
}
static VList <Pair <VList <LNode>, LNode> > GetCases(VList <LNode> body, IMessageSink sink)
{
var pairs = VList <Pair <VList <LNode>, LNode> > .Empty;
for (int i = 0; i < body.Count; i++)
{
bool isDefault;
if (body[i].Calls(S.Lambda, 2))
{
var key = new VList <LNode>(body[i][0].WithoutOuterParens());
pairs.Add(Pair.Create(key, AutoStripBraces(body[i][1])));
}
else if ((isDefault = IsDefaultLabel(body[i])) || body[i].CallsMin(S.Case, 1))
{
var alts = isDefault ? VList <LNode> .Empty : body[i].Args.SmartSelect(pat => AutoStripBraces(pat));
int bodyStart = ++i;
for (; i < body.Count && !IsDefaultLabel(body[i]) && !body[i].CallsMin(S.Case, 1); i++)
{
}
LNode handler;
if (i == bodyStart + 1)
{
handler = body[bodyStart];
}
else
{
handler = F.Braces(body.Slice(bodyStart, i - bodyStart));
}
pairs.Add(Pair.Create(alts, handler));
i--;
}
else
{
Reject(sink, body[i], "expected 'case _:' or '_ => _'");
break;
}
}
return(pairs);
}
static bool CaptureGroup(ref int c, ref int p, VList<LNode> cArgs, VList<LNode> pArgs, ref MMap<Symbol, LNode> captures, ref VList<LNode> attrs)
{
Debug.Assert(IsParamsCapture(pArgs[p]));
// The goal now is to find a sequence of nodes in cArgs that matches
// the sequence pArgs[p+1 .. p+x] where x is the maximum value such
// that none of the nodes in the sequence are $(params caps).
int saved_p = p, saved_c = c;
var savedCaptures = captures.AsImmutable();
var savedAttrs = attrs;
int captureSize = 0;
for (;; captureSize++) {
for (p++, c += captureSize; ; c++, p++) {
// If we run out of pArgs, great, we're done; if we run out
// of cArgs, the match fails, unless all remaining pArgs are
// $(params caps).
if (p >= pArgs.Count || IsParamsCapture(pArgs[p])) {
goto done_group;
} else {
if (c >= cArgs.Count)
return false;
if (!MatchesPatternNested(cArgs[c], pArgs[p], ref captures, ref attrs))
goto continue_group;
}
}
continue_group:;
p = saved_p;
c = saved_c;
attrs = savedAttrs;
captures = savedCaptures.AsMutable();
}
done_group:
AddCapture(captures, pArgs[saved_p], cArgs.Slice(saved_c, captureSize));
return true;
}
static VList<Pair<VList<LNode>,LNode>> GetCases(VList<LNode> body, IMessageSink sink)
{
var pairs = VList<Pair<VList<LNode>,LNode>>.Empty;
for (int i = 0; i < body.Count; i++) {
bool isDefault;
if (body[i].Calls(S.Lambda, 2)) {
var key = new VList<LNode>(body[i][0].WithoutOuterParens());
pairs.Add(Pair.Create(key, AutoStripBraces(body[i][1])));
} else if ((isDefault = IsDefaultLabel(body[i])) || body[i].CallsMin(S.Case, 1)) {
var alts = isDefault ? VList<LNode>.Empty : body[i].Args.SmartSelect(pat => AutoStripBraces(pat));
int bodyStart = ++i;
for (; i < body.Count && !IsDefaultLabel(body[i]) && !body[i].CallsMin(S.Case, 1); i++) {
}
LNode handler;
if (i == bodyStart + 1)
handler = body[bodyStart];
else
handler = F.Braces(body.Slice(bodyStart, i - bodyStart));
pairs.Add(Pair.Create(alts, handler));
i--;
} else {
Reject(sink, body[i], "expected 'case _:' or '_ => _'");
break;
}
}
return pairs;
}
/// <summary>Given the contents of case statement like `matchCode` or
/// `switch`, this method gets a list of the cases.</summary>
/// <returns>The first item in each pair is a list of the cases associated
/// with a single handler (for `default:`, the list is empty). The second
/// item is the handler code.</returns>
static internal VList<Pair<VList<LNode>, VList<LNode>>> GetCases(VList<LNode> body, IMessageSink sink)
{
var pairs = VList<Pair<VList<LNode>, VList<LNode>>>.Empty;
for (int i = 0; i < body.Count; i++)
{
bool isDefault;
if (body[i].Calls(S.Lambda, 2))
{
var alts = body[i][0].WithoutOuterParens().AsList(S.Tuple).SmartSelect(AutoStripBraces);
pairs.Add(Pair.Create(alts, body[i][1].AsList(S.Braces)));
} else
if ((isDefault = IsDefaultLabel(body[i])) || body[i].CallsMin(S.Case, 1))
{
var alts = isDefault ? VList<LNode>.Empty : body[i].Args.SmartSelect(AutoStripBraces);
int bodyStart = ++i;
for (; i < body.Count && !IsDefaultLabel(body[i]) && !body[i].CallsMin(S.Case, 1); i++) { }
var handler = new VList<LNode>(body.Slice(bodyStart, i - bodyStart));
pairs.Add(Pair.Create(alts, handler));
i--; // counteract i++ when loop repeats (redo)
} else
{
Reject(sink, body[i], "expected 'case _:' or '_ => _'");
break;
}
}
return pairs;
}