Transpilation: PatLang to idiomatic Ruby

A self-hosted Ruby transpiler (lib/transpile_ruby.patlang) walking the PRE-LOWERING AST directly (real if/while/def already present, unlike the flattened jump-based IR the ordinary compiler produces) to emit idiomatic Ruby — not an embedded PatLang VM ported to Ruby. Unsupported constructs (networking, the facts/logic engine, contracts, meta-compilation) fail the transpile with a named error rather than emitting silently-broken output. Reflection (lib/reflect.patlang, source → AST → JSON) is built the same way, reusing the existing self-hosted lexer/parser.

PatLang source:

make a function called fib takes n returns r
  if n < 2 then
    return n
  else
    return fib(n - 1) + fib(n - 2)
  end
end
let i = 0
while i < 8 do
  print(fib(i))
  let i = i + 1
end
print(10 / 3)
print(sqrt(-4))
new("Counter", "c1")
send("c1", "set", "v", 5)
print(get("c1", "v"))

Transpiled Ruby:

#!/usr/bin/env ruby
# Auto-generated by PatLang's self-hosted Ruby transpiler
# (self_hosting/lib/transpile_ruby.patlang). Do not edit by hand.
require_relative "patlang_runtime"

def fib(n)
  if (n < 2)
    return n
  else
    return (fib((n - 1)) + fib((n - 2)))
  end
end
i = 0
while (i < 8)
  puts(PL.display(fib(i)))
  i = (i + 1)
end
puts(PL.display(PL.div(10, 3)))
puts(PL.display(PL.sqrt((-4))))
PL.new_obj("Counter", "c1")
PL.send_obj("c1", "set", "v", 5)
puts(PL.display(PL.get_obj("c1", "v")))

Native run on the build machine (via a real `ruby` subprocess, output byte-identical to the interpreter's own):