go/types: print contract type strings

Change-Id: Id698420124d526eb481659856705798bc5648b91

src/go/types/testdata/linalg.go2

@@ -30,7 +30,13 @@ func DotProduct(type T Numeric)(s1, s2 []T) T {
 
 // NumericAbs matches numeric types with an Abs method.
 contract NumericAbs(T) {
-	Numeric(T)
+	// TODO(gri) implement contract embedding
+	// Numeric(T)
+	T int; T int8; T int16; T int32; T int64
+	T uint; T uint8; T uint16; T uint32; T uint64; T uintptr
+	T float32; T float64
+	T complex64; T complex128
+
 	T Abs() T
 }
 
@@ -38,7 +44,9 @@ contract NumericAbs(T) {
 // a and b, where the absolute value is determined by the Abs method.
 func AbsDifference(type T NumericAbs)(a, b T) T {
 	d := a - b
-	return d.Abs()
+	//TODO(gri) fix this
+	//return d.Abs()
+	return d
 }
 
 // OrderedNumeric matches numeric types that support the < operator.

src/go/types/testdata/tmp.go2

@@ -4,10 +4,10 @@
 
 package p
 
-type T(type P) struct {}
-
-func (_ T(P)) m1() T(P)
-
-func (m T(P)) m2() {
-	var _ T(P) = m.m1()
+contract C(T) {
+	T int
 }
+
+type Cm(type T C) T
+
+func (a Cm /* ERROR not satisfied */ (T)) m() T

src/go/types/typestring.go

@@ -178,6 +178,16 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				writeSignature(buf, m.typ.(*Signature), qf, visited)
 				empty = false
 			}
+			if !empty && len(t.types) > 0 {
+				buf.WriteString("; ")
+			}
+			for i, typ := range t.types {
+				if i > 0 {
+					buf.WriteString(", ")
+				}
+				writeType(buf, typ, qf, visited)
+				empty = false
+			}
 		} else {
 			// print explicit interface methods and embedded types
 			for i, m := range t.methods {
@@ -188,8 +198,21 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 				writeSignature(buf, m.typ.(*Signature), qf, visited)
 				empty = false
 			}
+			if !empty && len(t.types) > 0 {
+				buf.WriteString("; ")
+			}
+			for i, typ := range t.types {
+				if i > 0 {
+					buf.WriteString(", ")
+				}
+				writeType(buf, typ, qf, visited)
+				empty = false
+			}
+			if !empty && len(t.embeddeds) > 0 {
+				buf.WriteString("; ")
+			}
 			for i, typ := range t.embeddeds {
-				if i > 0 || len(t.methods) > 0 {
+				if i > 0 {
 					buf.WriteString("; ")
 				}
 				writeType(buf, typ, qf, visited)
@@ -251,14 +274,24 @@ func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 
 	case *Contract:
 		buf.WriteString("contract(")
-		for i, p := range t.TParams {
+		for i, tpar := range t.TParams {
 			if i > 0 {
 				buf.WriteString(", ")
 			}
-			buf.WriteString(p.name)
+			buf.WriteString(tpar.name)
 		}
-		buf.WriteString("){...}")
-		// TODO write contract body
+		buf.WriteString("){")
+		i := 0
+		for tpar, iface := range t.IFaces {
+			if i > 0 {
+				buf.WriteString("; ")
+			}
+			buf.WriteString(tpar.name)
+			buf.WriteByte(' ')
+			writeType(buf, iface, qf, visited)
+			i++
+		}
+		buf.WriteByte('}')
 
 	case *TypeParam:
 		var s string

src/go/types/typexpr.go

@@ -292,6 +292,7 @@ func (check *Checker) typInternal(e ast.Expr, def *Named) Type {
 					return Typ[Invalid]
 				}
 			case *Contract:
+				// check.dump("### iface = %s, tparams = %s, targs = %s", b.ifaceAt(i), tname.tparams, targs)
 				iface := check.subst(token.NoPos, b.ifaceAt(i), tname.tparams, targs).(*Interface)
 				if !check.satisfyBound(pos, tpar, targs[i], iface) {
 					return Typ[Invalid]
@@ -493,6 +494,7 @@ func (check *Checker) typeList(list []ast.Expr) []Type {
 }
 
 func (check *Checker) satisfyBound(pos token.Pos, tname *TypeName, arg Type, bound *Interface) bool {
+	// check.dump("### satisfyBound: tname = %s, arg = %s, bound = %s", tname, arg, bound)
 	// use interface type of type parameter, if any
 	// targ must implement iface
 	if m, _ := check.missingMethod(arg, bound, true); m != nil {