Add megaType procs

src/preserves/private/preserves_schema_nim.nim

@@ -349,14 +349,15 @@ proc generateNimFile*(scm: Schema; path: string) =
     knownTypes: TypeTable
     typeSection = newNode nkTypeSection
     procs: seq[PNode]
+    megaType: PNode
   if scm.embeddedType == "":
     typeSection.add nn(nkTypeDef,
-      ident"EmbeddedType",
+      exportIdent"EmbeddedType",
       newEmpty(),
       ident"void")
   else:
     typeSection.add nn(nkTypeDef,
-      ident"EmbeddedType",
+      exportIdent"EmbeddedType",
       newEmpty(),
       scm.embeddedType.ident)
     typeSection.add nn(nkTypeDef,
@@ -371,6 +372,11 @@ proc generateNimFile*(scm: Schema; path: string) =
     else:
       var name = name
       name[0] = name[0].toUpperAscii
+      if megaType.isNil:
+        megaType = ident(name)
+      else:
+        megaType = nn(nkInfix,
+          ident"|", megaType, ident(name))
       let t = nimTypeOf(scm, knownTypes, def, name)
       t.comment = "``" & $def & "``"
       case def.kind
@@ -417,6 +423,34 @@ proc generateNimFile*(scm: Schema; path: string) =
     ident"std/typetraits",
     ident"preserves")
   collectRefImports(imports, scm)
+  procs.add nn(nkProcDef,
+      "$".ident.accQuote.toExport,
+      newEmpty(),
+      newEmpty(),
+      nn(nkFormalParams,
+        ident"string",
+        nn(nkIdentDefs,
+          ident"x",
+          megaType,
+          newEmpty())),
+      newEmpty(),
+      newEmpty(),
+      nn(nkStmtList,
+        nn(nkCall, ident"$", nn(nkCall, ident"toPreserve", ident"x", ident"EmbeddedType"))))
+  procs.add nn(nkProcDef,
+      "encode".ident.accQuote.toExport,
+      newEmpty(),
+      newEmpty(),
+      nn(nkFormalParams,
+        nn(nkBracketExpr, ident"seq", ident"byte"),
+        nn(nkIdentDefs,
+          ident"x",
+          megaType,
+          newEmpty())),
+      newEmpty(),
+      newEmpty(),
+      nn(nkStmtList,
+        nn(nkCall, ident"encode", nn(nkCall, ident"toPreserve", ident"x", ident"EmbeddedType"))))
   var module = newNode(nkStmtList).add(
       imports,
       typeSection