Skip to content

Instantly share code, notes, and snippets.

View philzook58's full-sized avatar

Philip Zucker philzook58

View GitHub Profile
@philzook58
philzook58 / README.md
Last active January 1, 2022 22:56
js_of_ocaml custom directory
dune build main.bc.js --release
node _build/default/main.bc.js

Returns

$node _build/default/main.bc.js
/home/philip/Documents/ocaml/bapjs2/jsoo_crash/_build/default/main.bc.js:3937
 {r += exn[1][1];
@philzook58
philzook58 / README.md
Last active December 31, 2021 13:21
Bap Stack overflow error in js_of_ocaml

Build with dune build main.bc.js --release Demonstrates stack overflow on dynlinking the bap_c library.

Troubleshooting is difficult. Unfortunately the overflow error is being caught and translated in a way that obscures the original cause. To find what I believe is an accurate stack trace do the following: Go into _build/default/main.bc.js. Add Error.stackTraceLimit = Infinity; to the top. Grep for RangeError. Add in console.log(e.stack); into the exception handler like so

     {if(e instanceof Array)return e;
      if
       (joo_global_object.RangeError
 &&
@philzook58
philzook58 / bapjs.ml
Created November 5, 2021 03:55
Attempting to js_of_ocaml bap
(*
ocamlfind ocamlc -package bap -package core_kernel -linkpkg -linkall baptest.ml
js_of_ocaml +dynlink.js +toplevel.js +zarith_stubs_js/runtime.js +zarith_stubs_js/biginteger.js \
+base/base_internalhash_types/runtime.js +base/runtime.js +time_now/runtime.js +bin_prot/runtime.js \
+ppx_expect/collector/runtime.js +base_bigstring/runtime.js +core_kernel/strftime.js +core_kernel/runtime.js \
+bigstringaf/runtime.js --linkall --extern-fs --toplevel a.out
*)
open Core_kernel
open Bap.Std
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#define FLAG_BUFFER 128
#define MAX_SYM_LEN 4
typedef struct Stonks {
int shares;
@philzook58
philzook58 / z3kanren.py
Created May 22, 2021 15:03
A Kanren abusing Z3 to full extent
import operator
from z3 import *
def lift(z3assert):
def res(s):
s.push()
s.add(z3assert)
if s.is_good():
yield
s.pop()
(*|
A data structure that I've been more and more interested in recently is the disjoint set datastructure or union-find.
https://en.wikipedia.org/wiki/Disjoint-set_data_structure It's used in egraphs, unification, prolog, and graph connectivity.
I realized a cute representation that is easy to use and prover stuff about, although very inefficient compared to the usual version of disjoint set. It uses a simple functional representation based off the observation that the preimages of a function form disjoint sets. This representation is somewhat analogous to using functions to represent Maps in Coq like in Software Foundations. https://softwarefoundations.cis.upenn.edu/lf-current/Maps.html
The nice thing about this is that it really avoids any termination stickiness. Termination of the `find_root` operation of a union find in an explicit array or tree is not at all obvious and requires side proof or a refined type.
The termination ultimately comes from the fact that you used a finite number of unions to cons
@philzook58
philzook58 / IntDisjointMap.jl
Created March 30, 2021 18:08
disjoint set map in julia
struct IntDisjointMap
parents::Vector{Int64}
values::Vector{Any}
merge_fun
end
IntDisjointMap(merge_fun) = IntDisjointMap(Vector{Int64}[], [], merge_fun)
Base.length(x::IntDisjointMap) = length(x.parents)
@philzook58
philzook58 / cat.rs
Created March 14, 2021 04:07
Egg categories
use egg::{*, rewrite as rw};
use wasm_bindgen::prelude::*;
use std::time::Duration;
define_language! {
enum CatLanguage {
// string variant with no children
"id" = IdMorph(Id),
"om" = OTimesM([Id; 2]),
"oo" = OTimesO([Id; 2]),
@philzook58
philzook58 / Instructions.md
Last active March 7, 2021 21:56
Generate Egg programs from Metatheory.jl
@philzook58
philzook58 / cat.jl
Last active March 7, 2021 21:32
type tagged Category theor in metatheory.,jly
using Pkg
Pkg.activate("metatheory")
Pkg.add(url="https://github.com/0x0f0f0f/Metatheory.jl.git")
using Metatheory
using Metatheory.EGraphs
cat_theory = @theory begin
hom(hom(f, ob(a), ob(b)) ⋅ hom(id(ob(b)), ob(b), ob(b)), ob(a), ob(b)) == hom(f, ob(a), ob(b))
hom(hom(id(ob(a)), ob(a), ob(a)) ⋅ hom(f, ob(a), ob(b)), ob(a), ob(b)) == hom(f, ob(a), ob(b))
hom(hom(f, ob(a), ob(b)) ⋅ hom(hom(g, ob(b), ob(c)) ⋅ hom(h, ob(c), ob(d)), ob(b), ob(d)), ob(a), ob(d)) == hom(hom(hom(f, ob(a), ob(b)) ⋅ hom(g, ob(b), ob(c)), ob(a), ob(c)) ⋅ hom(h, ob(c), ob(d)), ob(a), ob(d))