ralexstokes

Casper Purity Checker LLL Walk-through

WARNING: These are notes and are not complete, they may contain errors. They certainly contain awkward language (sorry).

These are my notes from reading the Casper LLL Purity Checker currently being reviewed here: ethereum/casper#143

Specifically, the casper/contracts/purity_checker.py file.

Preamble -- Contract creation

ralexstokes

(return 0 
    (lll 
        (with '__funid 
            (div (calldataload 0) 
                26959946667150639794667015087019630673637144422540572481103610249216
            )
            (seq
                (set 'mask 
                    57897811465722876096115075801844696845150819816717216876035649536196444422144
                )

ralexstokes

(ns spec-calculator.core
  (:require [clojure.spec.alpha :as s]))

(def ops {'+ +
          '- -
          '* *
          '/ /})

(defn op-for [op]
  (get ops op))

ralexstokes

Keybase proof

I hereby claim:

• I am ralexstokes on github.
• I am ralexstokes (https://keybase.io/ralexstokes) on keybase.
• I have a public key ASDMmUcmwR2mJyxznMUQgkpc-DrLbLvDckXhw6pw6bAm6go

To claim this, I am signing this object:

ralexstokes

fn foo() {
  let y = if true { 4 } else { 10 };
  println!("{}", y);
}

// fails; returns () from if expression, compiler suggests an else is missing
fn bar() {
  let y = if true { 5 };
  println!("{}", y);
}

ralexstokes

@@ -1033,8 +1033,15 @@ RedisClient.prototype.hmset = function (args, callback) {
          callback = null;
      }
  
 -    if (args.length === 2 && typeof args[0] === "string" && typeof args[1] === "object") {
 +    if (args.length === 2 && (typeof args[0] === "string" || typeof args[0] === "number") && typeof args[1] === "object") {
          // User does: client.hmset(key, {key1: val1, key2: val2})
 +        // assuming key is a string, i.e. email address
 +
 +        // if key is a number, i.e. timestamp, convert to string