}

// EmbeddedTerm = [ "~" ] Type .
func (p *parser) embeddedTerm() Expr {
	if trace {
		defer p.trace("embeddedTerm")()
	}

	if p.tok == _Operator && p.op == Tilde {
		t := new(Operation)
		t.pos = p.pos()
		t.Op = Tilde
		p.next()
		t.X = p.type_()
		return t
	}

	t := p.typeOrNil()
	if t == nil {
		t = p.badExpr()
		p.syntaxError("expected ~ term or type")

			// representable by each specific type in the type set of T.
			return Tp.is(func(t *term) bool {
				if t == nil {
					return false
				}
				// A term may be a tilde term but the underlying
				// type of an untyped value doesn't change so we
				// don't need to do anything special.
				newType, _, _ := check.implicitTypeAndValue(x, t.typ)
				return newType != nil

				// first function that got substituted => allocate new out slice
				// and copy all functions
				new := make([]*Term, len(in))
				copy(new, out)
				out = new
				copied = true
			}
			out[i] = NewTerm(t.tilde, u)
		}
	}
	return
}

// replaceRecvType updates any function receivers that have type old to have
// type new. It does not modify the input slice; if modifications are required,

			// representable by each specific type in the type set of T.
			return Tp.is(func(t *term) bool {
				if t == nil {
					return false
				}
				// A term may be a tilde term but the underlying
				// type of an untyped value doesn't change so we
				// don't need to do anything special.
				newType, _, _ := check.implicitTypeAndValue(x, t.typ)
				return newType != nil

				// first function that got substituted => allocate new out slice
				// and copy all functions
				new := make([]*Term, len(in))
				copy(new, out)
				out = new
				copied = true
			}
			out[i] = NewTerm(t.tilde, u)
		}
	}
	return
}

// replaceRecvType updates any function receivers that have type old to have
// type new. It does not modify the input slice; if modifications are required,

		{"!\"#$%&'()*+,-.／:;<=>?@[\\]^_`{|}~", true},
		{"␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏␐␑␒␓␔␕␖␗␘␙␚␛␜␝␞␟␡", true},
		{"trailing VT␋/trailing VT␋", true},
		{"␋leading VT/␋leading VT", true},
		{"~leading tilde", true},
		{"\rleading CR", true},
		{"\nleading LF", true},
		{"\tleading HT", true},
		{"trailing CR\r", true},
		{"trailing LF\n", true},
		{"trailing HT\t", true},
		// cases for which test should fail.

		var terms []*Term
		if !tp.is(func(t *term) bool {
			if t == nil {
				return false
			}
			if r := f(t.typ); r != nil {
				terms = append(terms, NewTerm(t.tilde, r))
				return true
			}
			return false
		}) {
			return nil
		}

		// We can type-check this fine but we're introducing a synthetic
		// type parameter for the result. It's not clear what the API

	// embed it in an implicit interface so that only interface type-checking
	// needs to take care of such type expressions.
	if op, _ := x.(*syntax.Operation); op != nil && (op.Op == syntax.Tilde || op.Op == syntax.Or) {
		t := check.typ(&syntax.InterfaceType{MethodList: []*syntax.Field{{Type: x}}})
		// mark t as implicit interface if all went well
		if t, _ := t.(*Interface); t != nil {
			t.implicit = true
		}

		var terms []*Term
		if !tp.is(func(t *term) bool {
			if t == nil {
				return false
			}
			if r := f(t.typ); r != nil {
				terms = append(terms, NewTerm(t.tilde, r))
				return true
			}
			return false
		}) {
			return nil
		}

		// We can type-check this fine but we're introducing a synthetic
		// type parameter for the result. It's not clear what the API

	// embed it in an implicit interface so that only interface type-checking
	// needs to take care of such type expressions.
	wrap := false
	switch op := x.(type) {
	case *ast.UnaryExpr:
		wrap = op.Op == token.TILDE
	case *ast.BinaryExpr:
		wrap = op.Op == token.OR
	}
	if wrap {
		x = &ast.InterfaceType{Methods: &ast.FieldList{List: []*ast.Field{{Type: x}}}}
		t := check.typ(x)