Initial work on pipelines

faststreams/pipelines.nim

@@ -0,0 +1,28 @@
+import
+  macros,
+  input_stream, output_stream
+
+export
+  input_stream, output_stream
+
+macro executePipeline*(start: InputStream, steps: varargs[untyped]) =
+  var input = start
+  result = newStmtList()
+
+  for i in 0 .. steps.len - 2:
+    var
+      step = steps[i]
+      outputVar = genSym(nskVar, "out")
+      output = if i == steps.len - 2: steps[^1]
+               else: newCall(bindSym"memoryOutput")
+
+    result.add quote do:
+      var `outputVar` = `output`
+      `step`(`input`, `outputVar`)
+
+    input = quote do:
+      memoryInput(getOutput(`outputVar`))
+
+  if defined(debugMacros) or defined(debugPipelines):
+    echo result.repr
+