> Julia breaks down the second wall — the wall between your high-level code and native assembly [...] you can take a peek behind the curtain of any function int

> Julia breaks down the second wall — the wall between your high-level code and native assembly [...] you can take a peek behind the curtain of any function into its LLVM Intermediate Representation as well as its generated assembly code — all within the REPL While I agree with the author in "betting on Julia", I do not think inspecting LLVM IR or assembly of individual functions in the REPL is as useful as a feature as the author thinks, because it gives an inaccurate picture of what the actual output will be. Peeking at the code at the level of functions means a non-inlined version of the function must be produced at the REPL, and anywhere else this function is used in your actual code, it will probably be inlined (the author's example certainly will) so it can be further optimized/eliminated by later passes. Furthermore, for a non-trivial function's dump, fundamental optimizations that increase code size (inlining, unrolling loops etc) would make the output confusing to compare with the Julia equivalents. Thus, I imagine a lower optimization level is used to produce readable REPL dumps. For a performance minded person (the only type of person who would care about ASM/LLVM dumps at a REPL) even this is not helpful.