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Comment by robin_reala | Hacker News Reader

As a commenter points out, that’d make programming a difficult pastime. Can’t think of a non-esolang without if and for apart from Brainfuck, and that’s got an f in the name.

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Easy in Common Lisp without sacrificing ergonomics or getting stuck in a Turing tarpit.

We'd make a small preamble to define new names for things like DEFUN, Lisp's operator to define new functions. No F's needed to do that either. We can do this by taking advantage of read-time evaluation.

First we get references to the symbols DEFMACRO and DEFUN.

    (eval-when (:compile-toplevel :load-toplevel :execute)
      (setq de*un (intern (map 'string 'code-char '(68 69 70 85 78))))
      (setq de*macro (intern (map 'string 'code-char '(68 69 70 77 65 67 82 79)))))

This technique can be used to access any symbol in Common Lisp that may have an F in it.

Now, to make life-without-F easy, we define new names for DEFMACRO (mac) and DEFUN (proc) without actually lexically referring to the F-infected symbols:

    (#.de*macro mac (&body r) `(,de*macro ,@r))
    
    (mac proc (&body r) `(,de*un ,@r))

Now we can define functions with PROC instead of DEFUN. Here's the Fibonacci function, with the F censored out. Note that we don't need IF since Lisp has the superior COND:

    (proc *ib (n)
      (cond
        ((= 0 n) 0)
        ((= 1 n) 1)
        (t (+ (*ib (- n 1)) (*ib (- n 2))))))

Test it:

    > (print (*ib 10))
    55

This is excellent! I was playing around with a lisp (hy) recently, and hadn't really used macros before then. It's amazing how much you can reengineer lisp from within to meet your needs, even if they're as small as "I don't want to use F".

I haven't seen any non-lisp languages that give you that kind of power, for better or worse.

I think that's cheating. 70 is just F with a different hat on.

Would it be better for you if we took the Nth symbol in alphabetical order from the list of 978 standard symbols? You could do that.

How about searching for all symbols with the letters DEMACRO that are 8 letters long? We could do that too.

The technique works so long as you can uniquely determine the symbol through some combination of standard Lisp functions that don't contain F. Lisp has a big library, so it's not tough.

"70" isn't a number that is associated to F in any common person's understanding, and the pronunciation of the number "70" in English has no objectionable F sounds, so I don't agree it's cheating. :)

A garbage reddit post produces this great comment - only on HN! :)

And somehow, my reply managed to avoid using that letter ...

With Rust you could get by with "match bool { true => ..., _ => ... }" and "loop { ... break }" I think.

Yeah, using a language with pattern matching should do the trick. Maybe OCaml or even F#.

rimshot

`unsafe` code is a little bit tough since the keyword have an F, unless there's another way to create unsound code by abusing rustc.

But you would not be able to define functions.

I infer from the wording in your comment that you consider Brainfuck to be a non-esolang. Your mind must operate on a different plane to mine!

It’s the most well known of the esolangs at least.

In Lil[0], avoiding "F" is doable, but not very convenient.

The if/elseif keywords are off the table, but you still have both explicit looping constructs and function declarations:

    while x ... end
    each x y z in w ... end
    on name x y do ... end

There are five primitive operators with "F": typeof (rarely needed), floor (inconvenient to work around but at least you still have % for modulo), first (can be replaced with indexing), flip (transpose a matrix/table; this could be replaced (slowly) with a user-defined function), fuse (join a list of strings into a single string; very difficult to do without, since Lil doesn't have a vanilla string-concat operator), format (string formatting; this removes tons of functionality and the easiest ways of working around not having fuse).

Most of the query forms (select, extract, and update expressions) would be OK, but they all need a "from" clause to specify the source table, so no dice.

What you're left with is still very much Turing-Complete, but much less ergonomic.

[0] http://beyondloom.com/tools/trylil.html

https://en.cppreference.com/w/cpp/language/charset:

“Mapping from source file (other than a UTF-8 source file)(since C++23) characters to the basic character set(until C++23)translation character set(since C++23) during translation phase 1 is implementation-defined, so an implementation is required to document how the basic source characters are represented in source files.”*

⇒ pre C++23, you could have a C++ compiler that used an Unicode “Pile of poo” (https://www.unicode.org/L2/L2017/17407-frowning-poo.pdf) instead of the letter F.

    if (x) { y; } → while (x) { y; break; }
    for (a; b; c) { d; } → a; while (b) { d; c; }

JavaScript gives you the ternary operator (?/:) to handle conditionals plus switch/case. Plus you get map/reduce methods on iterables, and you can write procedures with “const thing = ()=> {}”

I think I could write an arbitrarily complex program without major issue.

You could do a lot in assembly (which uses instructions like JNZ for "if"), as long as you don't need any floating point math.

I guess you can (at least in C ) use && where you would use “if” and a convoluted while where you could write a “for”.

    #include <stdio.h>

    int main() {
            int a = 1;
        
            switch(a) case 1: puts("there's always this");
    }

Switch accepts a statement. It does not have to be compound.

When you're dedicated and don't have to work in a large team:

ihatetheletterf.h:

    #define cond if
    #define loop for
    #define otherwise default
    #define untrue false
    #define real float

And when you work in a (large) team, they won't likely accept weird constructions just to avoid a letter anyway.

You just used the letter f 13 times to make that file, though.

> and a convoluted while where you could write a “for”

What's convoluted about it? A `for` is about as simple as syntactic sugar gets.

    for( a; b; c ) {
    }

is exactly equivalent to

    a;
    while( b ) {
      c;
    }

(OK, a variable declared in `a` will remain in scope after the while loop terminates, but the only way for this to have an effect on anything is if you intentionally refer to it afterwards, in which case you needed to predeclare it for the for loop too.)

happenstance x > 0:

per x in y:

You might be able to get by in Haskell if you avoid case expressions.

Unless and Each, in ruby?

whitespace

Definitely an esolang

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