adds simpler Nim's AST to/from NIF

compiler/icnif/icniftags.nim

@@ -0,0 +1,10 @@
+import "../../dist/nimony/src/lib" / [nifstreams]
+
+let
+  symIdTag* = registerTag("symId")
+  symTag* = registerTag("s")
+  typeIdTag* = registerTag("typeId")
+  typeTag* = registerTag("t")
+  sonsTag* = registerTag("sons")
+
+  modIdTag* = registerTag("modId")

compiler/icnif/nifbasics.nim

@@ -0,0 +1,19 @@
+import std/[tables]
+import ".." / [ast, lineinfos, msgs, options]
+import "../../dist/nimony/src/gear2" / modnames
+
+proc modname(moduleToNifSuffix: var Table[FileIndex, string]; module: PSym; conf: ConfigRef): string =
+  assert module.kind == skModule
+  let idx: FileIndex = module.position.FileIndex
+  # copied from ../nifgen.nim
+  result = moduleToNifSuffix.getOrDefault(idx)
+  if result.len == 0:
+    let fp = toFullPath(conf, idx)
+    result = moduleSuffix(fp, cast[seq[string]](conf.searchPaths))
+    moduleToNifSuffix[idx] = result
+    #echo result, " -> ", fp
+
+proc toNifSym*(sym: PSym; moduleToNifSuffix: var Table[FileIndex, string]; conf: ConfigRef): string =
+  let module = sym.originatingModule
+
+  result = sym.name.s & '.' & $sym.disamb & '.' & modname(moduleToNifSuffix, module, conf)