execute.md

run code-blocks in markdown files and insert the results immediately below, like a home-brewed jupyter notebook.

• basic functionality
• additional languages
• matplotlib support (TODO)

Usage:

Either

1. execute with ./execute_md.py [SOURCE] [DEST] or ./execute_md.py [SOURCE] (which will print results to stdout), or

2. use it through python (or whatever you want to FFI that to)

from execute_md import execute_md
open('dest.md', 'w').writelines(execute_md(open('src.md', 'r'))) 

---

Test Cases

A standard, unflagged codeblock

This'll be ignored

A codeblock designed to be run

The following block starts with

'''python#run

def f(x):
  if x <= 1: return 1
  return x * f(x-1)

print([f(x) for x in range(6)])

[1, 1, 2, 6, 24, 120]

The #run tag is stripped from the final output, leaving us with just a codeblock starting with '''python, followed by a second codeblock with output.

Shared interpreter demo

Again, just done with '''python#run.

print(f(10))

3628800

A new interpreter instance

This one uses one additional tag, now looking like '''python#run#new. Snazzy.

print(f(11))

Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'f' is not defined

Unboxed output

'''python#run#unboxed

print('This is a test of *various* **markdown** ~~features~~.')

This is a test of various markdown features.

Hidden input-field with #hide

The source code block here looks like the following:

'''python#run#hide
print(1+2)
'''

However that gets dropped from the file, leaving us with just

3

Inverted output order

This one uses '''python#run#output_first:

7

print(3+4)

These tags can, of course, be combined. Just look at this very sentence in README_src.md 😉

Languages

🦀 rust 🦀

fn main() {
    let x = 2;
    let y = 3;
    println!("{}", x + y);
}

5

fn main() {
    this is a syntax error
}

error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `is`
 --> <anon>:2:10
  |
2 |     this is a syntax error
  |          ^^ expected one of 8 possible tokens

error: aborting due to previous error

🐍 python 🐍

print(2+2)

4

c

#include <stdio.h>
#include <math.h>
int main() {
    float x = 5.0;
    float y = 0.4;
    printf("%f\n", sqrt(x*y));
    return 0;
}

1.414214

c++

#include <iostream>
#include <cmath>
int main() {
    float x = 1.;
    float y = 2.;
    std::cout << sqrt(-1) << std::endl;
    return 0;
}

nan

bash 🐚

# print the first few prime numbers separated by dashes
for ((i=2; i<37; i++)); do
    for ((j=2; j<i; j++)); do
        if (($i % $j == 0)); then break; fi
    done
    if (($i == $j)); then echo -n $i"-"; fi
done

# then finish off a few more with awk
awk 'BEGIN { RS = " "; ORS = "|" } {
    for (i=2; i<$1; i++) {
        if ($1 % i == 0) break
        if ($1 == i+1) print $1
    }
} END { ORS = "\n"; print "" }' <<< $(seq 37 100)

2-3-5-7-11-13-17-19-23-29-31-37|41|43|47|53|59|61|67|71|73|79|83|89|97|

go

package main
import "fmt"

func main() {
    fmt.Println("go" + "lang")
}

golang

JS 🟨

const x = '7'
const y = 1
console.log(x - y)
console.log(x + y)

6
71

Lua

local a = {1, nil, "test"}

for key, value in pairs(a) do
  local b = value and print(value)
end

1
test

Kotlin

import kotlin.math.*

infix fun Int.greaterThanExp(x: Int) = this > exp(x.toFloat())

fun factorial(x: Int): Int = when (x) {
    0    -> 1
    else -> x * factorial(x - 1)
}

println(factorial(5) greaterThanExp 6)
println(factorial(6) greaterThanExp 7)
println(factorial(7) greaterThanExp 8)

false
false
true

---

Haskell

main = (putStrLn . reverse) "!dlrow olleh"

hello world!

Nim 👑

proc factorial(x: int): int =
    if x <= 0: 1
    else: x * factorial(x - 1)
  
echo "10! = ", factorial(10)

10! = 3628800

Haxe

class Main {
    static public function main() {
        trace("hello world");
    }
}

Main.hx:3: hello world

OCaml 🐫

print_string "hello world\n"

hello world

Java ☕

class Main{
    public static void main(String[] args){
        System.out.println("hello world!");
    }
}

hello world!

Zsh

echo "hello world!"

hello world!

Brainfuck

(example sourced from Wikipedia)

++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>
---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.

Hello World!