| // Copyright 2019 The LUCI Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package lucicfg |
| |
| import ( |
| "go.starlark.net/starlark" |
| ) |
| |
| // sequences is a mapping "name -> int", mutable via `sequence_next()` calls. |
| type sequences struct { |
| s map[string]int |
| } |
| |
| // next returns the next number in the given sequence. |
| // |
| // Sequences start with 1. |
| func (s *sequences) next(seq string) int { |
| if s.s == nil { |
| s.s = make(map[string]int, 1) |
| } |
| v := s.s[seq] + 1 |
| s.s[seq] = v |
| return v |
| } |
| |
| func init() { |
| // sequence_next(name) returns a next integer in the sequence. |
| declNative("sequence_next", func(call nativeCall) (starlark.Value, error) { |
| var name starlark.String |
| if err := call.unpack(1, &name); err != nil { |
| return nil, err |
| } |
| return starlark.MakeInt(call.State.seq.next(name.GoString())), nil |
| }) |
| } |