λ☶ (pronounced Lambda Mountain) is a typed macro assembler that provides a relatively clean implementation of System F<: with Specialization.
Despite being an assembler, LM provides
- self-hosting (LM is written in LM)
- algebraic data types
- parameterized code and data
- hygienic macros
- platform agnostic standard libraries
LM is currently about 4000 lines of code. LM solves an N by M Problem with language frontends vs language backends. The LM project might interface with larger codebases that define frontends or backends, but the core LM Calculus can stay small.
An assembler takes pieces of data and sticks them together. Assemblers don't always understand the meaning of what they do, they just do it.
A fragment is a Key-Value Map of Strings to S-Expressions. This data structure permits more detailed manipulation of code than a typical assembler.