  We present a C-language implementation of the lambda-pi calculus by extending
the (call-by-need) stack machine of Ariola, Chang and Felleisen to hold types,
using a typeless- tagless- final interpreter strategy. It has the advantage of
expressing all operations as folds over terms, including by-need evaluation,
recovery of the initial syntax-tree encoding for any term, and eliminating most
garbage-collection tasks. These are made possible by a disciplined approach to
handling the spine of each term, along with a robust stack-based API. Type
inference is not covered in this work, but also derives several advantages from
the present stack transformation. Timing and maximum stack space usage results
for executing benchmark problems are presented. We discuss how the design
choices for this interpreter allow the language to be used as a high-level
scripting language for automatic distributed parallel execution of common
scientific computing workflows.
