/
stacks.go
91 lines (75 loc) · 2.32 KB
/
stacks.go
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// Copyright 2019 Google LLC
//
// 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 transpiler
import (
mpb "github.com/Lakshmi-Priya-Ramisetty/healthcare-data-harmonization/mapping_engine/proto" /* copybara-comment: mapping_go_proto */
)
// Welcome to a language with no generics :'(
type valueStack []*mpb.ValueSource
func (s *valueStack) push(v *mpb.ValueSource) *mpb.ValueSource {
*s = append(*s, v)
return v
}
func (s *valueStack) peek() *mpb.ValueSource {
return (*s)[len(*s)-1]
}
func (s *valueStack) pop() *mpb.ValueSource {
p := s.peek()
*s = (*s)[:len(*s)-1]
return p
}
// and creates a ValueSource from this valueStack, along with any other ValueSources, by passing
// them all through _And. This requires all sources in the stack and arguments to be boolean.
func (s *valueStack) and(others ...*mpb.ValueSource) *mpb.ValueSource {
if len(*s) == 0 && len(others) == 0 {
return nil
}
if len(*s) == 1 && len(others) == 0 {
return s.peek()
}
if len(*s) == 0 && len(others) == 1 {
return others[0]
}
vs := &mpb.ValueSource{
Projector: "$And",
}
addArgs(vs, *s...)
addArgs(vs, others...)
return vs
}
// addArgs adds the given args to the given ValueSource, as sources. The first arg will go into
// Source, while the rest will become additionalArgs. Does not overwrite existing sources/args,
// appends everything.
func addArgs(vs *mpb.ValueSource, arg ...*mpb.ValueSource) {
for _, a := range arg {
if vs.Source == nil {
if a.Projector == "" {
vs.Source = a.Source
} else {
vs.Source = &mpb.ValueSource_ProjectedValue{
ProjectedValue: a,
}
}
} else {
vs.AdditionalArg = append(vs.AdditionalArg, a)
}
}
}
func projectAndSimplify(projector string, args ...*mpb.ValueSource) *mpb.ValueSource {
vs := &mpb.ValueSource{
Projector: projector,
}
addArgs(vs, args...)
return vs
}