// isCompatible reports whether t and u are of compatible types.
func isCompatible(t, u types.Type) bool {
if types.Equal(t, u) {
return true
}
if t, ok := t.(types.Numerical); ok {
if u, ok := u.(types.Numerical); ok {
// TODO: Check for other compatible types (e.g. pointers, array names,
// strings).
return t.IsNumerical() && u.IsNumerical()
}
}
return false
}
// isCompatibleArg reports whether the given call argument and function
// parameter types are compatible.
func isCompatibleArg(arg, param types.Type) bool {
if isCompatible(arg, param) {
return true
}
if arg, ok := arg.(*types.Array); ok {
if param, ok := param.(*types.Array); ok {
// TODO: Check for other compatible types (e.g. pointers, array names,
// strings).
if param.Len != 0 {
return false
}
return types.Equal(arg.Elem, param.Elem)
}
}
return false
}
// Insert inserts the given declaration into the current scope.
func (s *Scope) Insert(decl ast.Decl) error {
// Early return for first-time declarations.
ident := decl.Name()
if ident == nil {
// Anonymous function parameter declaration.
return nil
}
name := ident.String()
prev, ok := s.Decls[name]
if !ok {
s.Decls[name] = decl
return nil
}
prevIdent := prev.Name()
if prevIdent.NamePos == ident.NamePos {
// Identifier already added to scope.
return nil
}
// Previously declared.
if !types.Equal(prev.Type(), decl.Type()) {
return errors.Newf(ident.Start(), "redefinition of %q with type %q instead of %q", name, decl.Type(), prev.Type())
}
// The last tentative definition becomes the definition, unless defined
// explicitly (e.g. having an initializer or function body).
if !s.IsDef(prev) {
s.Decls[name] = decl
return nil
}
// Definition already present in scope.
if s.IsDef(decl) {
// TODO: Consider adding support for multiple errors (and potentially
// warnings and notifications).
//
// If support for notifications are added, add a note of the previous declaration.
// errors.Notef(prevIdent.Start(), "previous definition of %q", name)
return errors.Newf(ident.Start(), "redefinition of %q", name)
}
// Declaration of previously declared identifier.
return nil
}