move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/gen/_template/interface_slice.tmpl

@@ -0,0 +1,94 @@
+{{- /*gotype: go.mau.fi/mautrix-telegram/pkg/gotd/gen.interfaceDef*/ -}}
+{{ define "interface_slice" }}{{ $f := . }}
+{{ template "slice" $f }}
+
+{{ range $field := sortableFields ($f.SharedFields.Common) }}
+{{ template "slice_sort_by" concat ($f) ($field) }}
+{{ end }}
+
+{{ range $s := $f.Constructors }}{{ if $s.Fields }}
+{{ range $field := mapCollectableFields ($f.SharedFields.Common) }}
+{{ template "slice_collect_to_map" concat ($f) ($field) ($s.Name) }}
+{{ end }}
+
+// As{{ $s.Name }} returns copy with only {{ $s.Name }} constructors.
+func (s {{ template "slice_name" $f }}) As{{ $s.Name }}() (to {{ template "slice_name" $s }}) {
+    for _, elem := range s {
+        value, ok := elem.(*{{ $s.Name }})
+        if !ok {
+            continue
+        }
+        to = append(to, *value)
+    }
+
+    return to
+}
+{{- end }}{{- end }}
+
+{{ range $mapping := $f.Mappings }}{{- if (not $mapping.Constructor) }}
+
+{{- range $field := mapCollectableFields (index ($f.SharedFields) ($mapping.MapperName)) }}
+{{- /*gotype: go.mau.fi/mautrix-telegram/pkg/gotd/gen.fieldDef*/ -}}
+// Fill{{ $mapping.MapperName }}Map fills only {{ $mapping.MapperName }} constructors to given map.
+func (s {{ template "slice_name" $f }}) Fill{{ $mapping.MapperName }}{{ template "map_collector_name" $field }}Map(to map[{{ $field.Type }}]{{ template "print_mapper_type" $mapping }}) {
+    for _, elem := range s {
+        value, ok := elem.As{{ $mapping.MapperName }}()
+        if !ok {
+            continue
+        }
+        to[value.Get{{ $field.Name }}()] = value
+    }
+}
+
+// {{ $mapping.MapperName }}ToMap collects only {{ $mapping.MapperName }} constructors to map.
+func (s {{ template "slice_name" $f }}) {{ $mapping.MapperName }}To{{ template "map_collector_name" $field }}Map() map[{{ $field.Type }}]{{ template "print_mapper_type" $mapping }} {
+    r := make(map[{{ $field.Type }}]{{ template "print_mapper_type" $mapping }}, len(s))
+    s.Fill{{ $mapping.MapperName }}{{ template "map_collector_name" $field }}Map(r)
+    return r
+}
+{{ end }}
+
+// AppendOnly{{ $mapping.MapperName }} appends only {{ $mapping.MapperName }} constructors to
+// given slice.
+func (s {{ template "slice_name" $f }}) AppendOnly{{ $mapping.MapperName }}(to []{{ template "print_mapper_type" $mapping }}) []{{ template "print_mapper_type" $mapping }} {
+    for _, elem := range s {
+        value, ok := elem.As{{ $mapping.MapperName }}()
+        if !ok {
+            continue
+        }
+        to = append(to, value)
+    }
+
+    return to
+}
+
+// As{{ $mapping.MapperName }} returns copy with only {{ $mapping.MapperName }} constructors.
+func (s {{ template "slice_name" $f }}) As{{ $mapping.MapperName }}() (to []{{ template "print_mapper_type" $mapping }}) {
+    return s.AppendOnly{{ $mapping.MapperName }}(to)
+}
+
+{{- range $method := concat ("First") ("Last") }}
+// {{ $method }}As{{ $mapping.MapperName }} returns {{ lower $method }} element of slice (if exists).
+func (s {{ template "slice_name" $f }}) {{ $method }}As{{ $mapping.MapperName }}() (v {{ template "print_mapper_type" $mapping }}, ok bool) {
+    value, ok := s.{{ $method }}()
+    if !ok {
+        return
+    }
+    return value.As{{ $mapping.MapperName }}()
+}
+{{- end }}
+
+{{- range $method := concat ("PopFirst") ("Pop") }}
+// {{ $method }}As{{ $mapping.MapperName }} returns element of slice (if exists).
+func (s *{{ template "slice_name" $f }}) {{ $method }}As{{ $mapping.MapperName }}() (v {{ template "print_mapper_type" $mapping }}, ok bool) {
+    value, ok := s.{{ $method }}()
+    if !ok {
+        return
+    }
+    return value.As{{ $mapping.MapperName }}()
+}
+{{ end }}
+
+{{- end }}{{- end }}
+
+{{- end }}