Snippet Zone

Concatenative JavaScript

```
const vars = {}
```
```
 
```
```
const as = s => v => vars[s] = v
```
```
 
```
```
const def = s => v => {
```
```
  vars[s] = v
```
```
}
```
```
 
```
```
const set = (last, prop, val) => {
```
```
  last[prop] = val
```
```
}
```
```
 
```
```
const put = (last, prop, val) => {
```
```
  last[prop] = val
```
```
  return last
```
```
}
```
```
 
```
```
const of = k => run.last[k]
```
```
const $ = k => () => vars[k]
```
```
 
```
```
const run = (prog, log) => {
```
```
  run.stack = []
```
```
  let curr
```

  for (let i = 0; i < prog.length; i++) {

```
    let val = prog[i]
```
```
    if (val != null && val === $) { 
```
```
      run.stack.push(val())
```

    } else if (typeof val === 'function') {

```
      let ctx = null
```
```
      if (document.body[val.name]) { 
```
```
        ctx = document.body 
```
```
        val = val.bind(ctx)
```
```
      } else if (document[val.name]) { 
```
```
        ctx = document
```
```
        val = val.bind(ctx)
```
```
      } 
```
```
 
```
```
      if (log) console.log('exec', 
```

        val.name == 'bound ' ? '\u03BB' : val.name, run.stack)

```
 
```
```
      curr = val.apply(ctx, run.stack)
```
```
      if (curr != run.stack) { 
```

        run.stack = curr != null ? [curr] : []

```
        if (typeof curr === 'object') {
```
```
          run.last = curr
```
```
        }
```
```
      }
```
```
    } else {
```

      if (val != null) run.stack.push(val)

```
    }
```
```
  }
```
```
}
```
```
 
```
```
const showStack = () => {
```
```
  console.log('- stack:', run.stack)
```

  console.log('  -> last object', run.last)

```
  return run.stack
```
```
}
```
```
 
```
```
const _ = new Proxy({}, { 
```
```
  get: (o, key) => (() => (...a) => 
```
```
    run.last[key].apply(run.last, a)
```
```
  )()
```
```
})
```
```
 
```
```
// try it out
```
```
 
```
```
run( 
```
```
  [ 'div', 
```
```
    document.createElement, 
```
```
    document.body.appendChild, 
```
```
    as`myDiv`,
```

    'innerHTML', 'mini <b>concatenative</b>', set,

```
    'style', of, 'color', 'green', set,
```
```
 
```

    'just logging the element', $`myDiv`, console.log,

```
 
```
```
    'canvas', document.createElement, 
```
```
    document.body.appendChild, 
```
```
    'width', 500, put,
```
```
    'height', 500, put,
```
```
    def`myCanvas`,
```
```
 
```
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    '2d',
```
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    _.getContext,
```
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    'fillStyle', 'red', set,
```
```
    100, 30, _.translate,
```
```
    0, 0, 10, 100, _.fillRect,
```
```
    20, 0, 10, 100, _.fillRect,
```
```
    .2, _.rotate,
```
```
    -30, 25, 100, 10, _.fillRect,
```
```
    -20, 55, 100, 10, _.fillRect,
```
```
 
```
```
    {}, 
```
```
    'name', 'zevan', put,
```
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    'age', 82, put,
```
```
    JSON.stringify,
```
```
    as`person`,
```
```
 
```
```
    showStack
```
```
  ]
```
```
)
```
```
console.log(vars);
```

I recently spent some time reading about and playing with the FORTH language. I keep finding myself creating weird vaguely FORTH inspired snippets now… This one processes an array that’s in a concatenative format like this:


[ 'hello world', Date.now(), console.log ]

Arguments are collected on a stack and passed to a function when a function is hit in the array. There are some odd helper functions for setting properties, setting nested properties, running functions with a specific context etc…

Here is GPT4’s mostly correct explanation of what it does

This is a rather unusual piece of JavaScript code that creates a simple “programming language” based on the concept of a stack machine, and runs a “program” in this language. It resembles some sort of DSL (domain-specific language) or script-like construct.

Here are what the main components do:

vars: This is a dictionary that stores variables defined in the program.

as: This is a function that takes a string s and returns a function that takes a value v, storing v in vars under the key s.

def: Similar to as, it defines a variable in vars.

set: This function is used to set the property of an object. It takes the object last, the property name prop, and the value val, and assigns val to the property prop of the object last.

put: Similar to set, it sets the property of an object and returns the updated object.

of: This function gets the property with name k of the last object returned by the program.

$: This function is a getter for variables in vars.

run: This is the main function that runs the program. The program is an array of actions, where an action can be a function, an object with a name of ‘get’ (which pushes the result of calling the function onto the stack), or a value (which is pushed onto the stack).

showStack: This function logs the current state of the stack and the last object returned.

_: This creates a new Proxy object that allows arbitrary methods to be called on the last object returned by the program.

The run function is then called with a list of actions to perform. The actions include creating a div and canvas element, appending them to the body of the document, setting their properties, and drawing on the canvas. It also creates an object with a name and age, converts it to JSON, and stores it in a variable. Finally, it shows the state of the stack and logs all the variables.

July 23, 2023

// arrays // hacks // humor // javascript // meta // obfuscation // oldschool // proxies // speed-coded // speedcoding

Little Trading Program

```
let id = 0;
```
```
function person(startValue = 100) {
```
```
  const props = {
```
```
    id: id++, 
```
```
    el: document.body.appendChild(
```
```
      Object.assign(
```
```
        document.createElement`b`, { 
```
```
          innerText: startValue,
```
```
          style: 'padding: 1em'
```
```
      })
```
```
    ),
```
```
    value: startValue,
```
```
    trade(other) {
```
```
      if (props.value <= 0) return;
```
```
      other.value += 1;
```
```
      props.value -= 1;
```
```
      other.el.innerText = other.value
```
```
      props.el.innerText = props.value
```
```
    }
```
```
  }
```
```
  return props
```
```
}
```
```
 
```
```
 
```
```
const NUM = 4
```

const people = Array.from({ length: NUM }, person)

```
 
```
```
setInterval(() => {
```

  const a = people[~~(Math.random() * people.length)]

  const b = people[~~(Math.random() * people.length)]

```
 
```
```
  if (a.id != b.id) a.trade(b)
```
```
}, 1)
```

4 “people” randomly trade…

I asked Chat GPT to describe this… funny response…

The trading program you provided is essentially an example of a random walk or “drunkard’s walk” problem. In such problems, each individual (in this case, the ‘people’) make random moves (in this case, trades), and we observe the resulting dynamics of the system as a whole. In this particular case, each trade involves one individual giving one unit of value to another individual. Since each trade is random, there’s a possibility that over time, all the value might get concentrated in one individual. This isn’t guaranteed, but given enough time, it’s likely. You could compare it to the idea that given enough time, a group of monkeys randomly typing on a keyboard would eventually type out the complete works of Shakespeare. It’s also worth noting that this concentration of value becomes more likely because the individuals with no value left cannot trade anymore, so they are essentially removed from the trading pool. This progressively reduces the number of individuals that can gain value and increases the probability of the remaining individuals gaining more value. This is a simple model of economic transactions and it illustrates how wealth can concentrate over time even if all the transactions are fair and random. Of course, it’s a very simplified model, and real-world economics are much more complex.

July 18, 2023

// arrays // humor // javascript // math // speed-coded // speedcoding

Other Gates from NAND

```
const nand = ([a, b]) => +!(a & b)
```
```
 
```
```
const not = ([a]) => nand([a, a])
```
```
 
```

const and = ([a, b]) => nand([nand([a, b]), nand([a, b])])

```
 
```

const or = ([a, b]) => nand([nand([a, a]), nand([b, b])])

```
 
```
```
const nor = ([a, b]) => 
```
```
  nand([ 
```

    nand([nand([a, a]), nand([b, b])]),

```
    nand([nand([a, a]), nand([b, b])])
```
```
  ])
```
```
 
```
```
const xor = ([a, b]) =>
```
```
  nand([
```
```
    nand([a, nand([a, b])]),
```
```
    nand([b, nand([a, b])])
```
```
  ])
```
```
 
```
```
const xnor = ([a, b]) => 
```
```
  nand([ 
```
```
    nand([nand([a, a]), nand([b, b])]),
```
```
    nand([a, b])
```
```
  ])
```
```
 
```
```
 
```
```
const inputs = [
```
```
  [0, 0],
```
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  [0, 1],
```
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  [1, 0],
```
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  [1, 1]
```
```
]
```
```
 
```

const testGate = ({ gate, truth, result }) => console.log(

```
  gate + ' matches truth? ', 
```
```
  truth+'' === result+'' ? 
```

    'yes :D' : `nope :( ${truth} ${result}`

```
)
```
```
 
```
```
testGate({
```
```
  gate: 'NAND',
```
```
  truth: [1, 1, 1, 0],
```
```
  result: inputs.map(nand)
```
```
})
```
```
 
```
```
testGate({
```
```
  gate: 'NOT',
```
```
  truth: [0, 1],
```
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  result: [[1], [0]].map(not)
```
```
})
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```
 
```
```
testGate({
```
```
  gate: 'AND',
```
```
  truth: [0, 0, 0, 1],
```
```
  result: inputs.map(and)
```
```
})
```
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```
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testGate({
```
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  gate: 'OR',
```
```
  truth: [0, 1, 1, 1],
```
```
  result: inputs.map(or)
```
```
})
```
```
 
```
```
testGate({
```
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  gate: 'NOR',
```
```
  truth: [1, 0, 0, 0],
```
```
  result: inputs.map(nor)
```
```
})
```
```
 
```
```
testGate({
```
```
  gate: 'XOR',
```
```
  truth: [0, 1, 1, 0],
```
```
  result: inputs.map(xor)
```
```
})
```
```
 
```
```
testGate({
```
```
  gate: 'XNOR',
```
```
  truth: [1, 0, 0, 1],
```
```
  result: inputs.map(xnor)
```
```
})
```

Use NAND to create a bunch of other gates 😀 – I used this wikipedia article for reference

July 16, 2023

// arrays // golfed // humor // javascript // math

Object Key Order and Reflect.ownKeys

const obj = { 11: 'eleven', 23: 'twenty-three', 1: 'one', 2: 'two', '-1': 'negative 1' };

```
 
```
```
console.log(Reflect.ownKeys(obj))
```

I noticed that for in.. over an object was giving me weirdly consistent results across all browsers the other day and stumbled upon this.

Great news, but it’s Reflect.ownKeys for me… now that IE11 is dying/dead.

February 13, 2022

// arrays // objects // oldschool

Step Between Two Numbers

const stepBetweenA = (min, max, steps) =>

  Array(steps).fill(0).reduce((prev, curr, i) => {

    prev.push(min + ((max - min) / (steps - 1)) * i)

```
    return prev
```
```
  }, [])
```
```
 
```
```
 
```

const stepBetweenB = (min, max, steps) => {

```
  steps -= 1
```
```
  const diff = (max - min) / steps
```
```
  const result = [min]
```
```
  for (let i = 0; i < steps; i++) {
```
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    result.push(min += diff)
```
```
  }
```
```
  return result
```
```
}
```
```
 
```

console.log('a', stepBetweenA(10, 110, 4))

console.log('b', stepBetweenB(10, 110, 4))

```
 
```
```
const ITER = 10000
```
```
 
```
```
console.time('a')
```
```
for (let i = 0; i < ITER; i++) {
```
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  stepBetweenA(10, 110, 4)
```
```
}
```
```
console.timeEnd('a')
```
```
 
```
```
  console.time('b')
```
```
for (let i = 0; i < ITER; i++) {
```
```
  stepBetweenB(10, 110, 4)
```
```
}
```
```
console.timeEnd('b')
```

Two messy implementations for stepping between two numbers… I am not sure it’s possible to make console.time work well with the snippet zone quick editor – so if you want to see the times… open your console.

February 5, 2022

// arrays // javascript // math // speedcoding

Older Posts

Concatenative JavaScript

Here is GPT4’s mostly correct explanation of what it does

Little Trading Program

Other Gates from NAND

Object Key Order and Reflect.ownKeys

Step Between Two Numbers

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