This section provides a comprehensive, systematic catalog of all language features in LFE. It serves as a reference for understanding what constructs are available, their syntax, semantics, and usage patterns.
LFE is a Lisp-2 with:
Separate namespaces for functions and variablesS-expression syntax (homoiconic)Erlang semantics (immutable data, process-oriented, pattern matching)Full Erlang interoperability (zero-overhead FFI)Powerful macro system (compile-time code transformation)Multiple paradigm support (functional, concurrent, actor-based)
Language Characteristics :
Aspect Description
Type System Dynamically typed with optional Dialyzer specs Evaluation Eager/strict evaluation (call-by-value) Scoping Lexical scoping with environment-based bindings Closures Full closure support with lambda lifting Tail Calls Tail call optimization (via Erlang/BEAM) Concurrency Actor model (Erlang processes) Persistence All data structures immutable Memory Model Garbage collected, per-process heaps
quote cons car cdr list tuple binary map
lambda match-lambda
let let* letrec let-function letrec-function let-macro
progn if case receive try catch
call funcall function
defmodule defun defmacro defrecord defstruct
cond when unless do
let* flet fletrec flet*
lc bc qlc
caar cadr cdar cddr ... (c*r family)
list* != === !==
atom integer float string binary boolean
list tuple map record struct
function pid port reference
Arithmetic: + - * / div rem abs
Comparison: == /= =:= =/= < > =< >=
Boolean: not and or andalso orelse xor
Bitwise: band bor bxor bnot bsl bsr
Feature LFE Common Lisp Notes
Namespaces Lisp-2 Lisp-2 Separate function/variable namespaces Evaluation Eager Eager Call-by-value Typing Dynamic Dynamic Runtime type checking Macros Unhygienic Unhygienic Both support quasiquotation CLOS No Yes LFE uses Erlang behaviors instead Tail calls Yes (BEAM) Yes Proper TCO Concurrency Actors (processes) Threads Different models Mutability Immutable Mutable Erlang semantics
Feature LFE Scheme Notes
Namespaces Lisp-2 Lisp-1 LFE has separate namespaces Evaluation Eager Eager Both call-by-value Macros Unhygienic Hygienic (syntax-rules) LFE has unhygienic macros Continuations No Yes (call/cc) BEAM doesn't support Tail calls Yes Yes Both have proper TCO Numbers Erlang types Scheme numbers Different numeric tower
Feature LFE Clojure Notes
Platform BEAM/Erlang JVM Different VMs Namespaces Lisp-2 Lisp-1 Different conventions Data structures Erlang types Persistent collections Both immutable Concurrency Actors Agents/Atoms/STM Different models Macros Traditional Hygienic-ish Clojure has syntax-quote Typing Dynamic Dynamic Both with optional specs Performance BEAM-level JVM-level Different characteristics