void ValueBindingPattern(out PatternConstruct pattern)
{
VariableInitializer init; var modifier = ExpressoModifiers.None;
if (la.kind == 27) {
Get();
modifier = ExpressoModifiers.Immutable;
} else if (la.kind == 28) {
Get();
} else SynErr(132);
var inits = new List<VariableInitializer>();
PatternVarDef(out init);
inits.Add(init);
while (la.kind == 12) {
Get();
PatternVarDef(out init);
inits.Add(init);
}
pattern = PatternConstruct.MakeValueBindingPattern(inits, modifier);
}
void WildcardPattern(out PatternConstruct pattern)
{
Expect(77);
pattern = PatternConstruct.MakeWildcardPattern();
}
void PatternItem(out PatternConstruct pattern)
{
pattern = PatternConstruct.Null;
if (StartOf(15)) {
ExpressionPattern(out pattern);
} else if (la.kind == 14) {
IdentifierPattern(out pattern);
} else SynErr(137);
}
void TuplePattern(out PatternConstruct pattern)
{
var inners = new List<PatternConstruct>();
Expect(8);
while (StartOf(18)) {
if (StartOf(16)) {
LhsPattern(out pattern);
} else {
ExpressionPattern(out pattern);
}
inners.Add(pattern);
Expect(12);
}
Expect(10);
pattern = PatternConstruct.MakeTuplePattern(inners);
}
void Pattern(out PatternConstruct pattern)
{
pattern = null;
if (la.kind == 77) {
WildcardPattern(out pattern);
} else if (la.kind == 8) {
TuplePattern(out pattern);
} else if (IsDestructuringPattern()) {
DestructuringPattern(out pattern);
} else if (StartOf(15)) {
ExpressionPattern(out pattern);
} else SynErr(135);
}
void LhsPattern(out PatternConstruct pattern)
{
pattern = PatternConstruct.Null;
if (la.kind == 77) {
WildcardPattern(out pattern);
} else if (la.kind == 27 || la.kind == 28) {
ValueBindingPattern(out pattern);
} else if (IsIdentifierPattern()) {
IdentifierPattern(out pattern);
} else if (la.kind == 8) {
TuplePattern(out pattern);
} else if (la.kind == 9 || la.kind == 14) {
DestructuringPattern(out pattern);
} else SynErr(133);
}
void IdentifierPattern(out PatternConstruct pattern)
{
PatternConstruct inner = null; string name; AstType type = new PlaceholderType(TextLocation.Empty);
Expect(14);
name = t.val;
var ident = AstNode.MakeIdentifier(name, type, CurrentLocation);
Symbols.AddSymbol(name, ident);
if (la.kind == 78) {
Get();
LhsPattern(out inner);
}
pattern = PatternConstruct.MakeIdentifierPattern(ident, inner);
}
void ExpressionPattern(out PatternConstruct pattern)
{
Expression expr;
PatternOrTest(out expr);
pattern = PatternConstruct.MakeExpressionPattern(expr);
}
void DestructuringPattern(out PatternConstruct pattern)
{
pattern = PatternConstruct.Null; AstType type_path;
var patterns = new List<PatternConstruct>(); bool is_vector = false;
if (la.kind == 14) {
TypePathExpression(out type_path);
Expect(7);
if (StartOf(15)) {
PatternItem(out pattern);
patterns.Add(pattern);
}
while (la.kind == 12) {
Get();
PatternItem(out pattern);
patterns.Add(pattern);
}
Expect(11);
pattern = PatternConstruct.MakeDestructuringPattern(type_path, patterns);
} else if (la.kind == 9) {
Get();
if (StartOf(15)) {
PatternItem(out pattern);
patterns.Add(pattern);
}
while (NotFinalComma()) {
ExpectWeak(12, 19);
PatternItem(out pattern);
patterns.Add(pattern);
}
if (la.kind == 12) {
Get();
Expect(2);
is_vector = true;
}
Expect(3);
pattern = PatternConstruct.MakeCollectionPattern(patterns, is_vector);
} else SynErr(136);
}
