Cello · High Level C

#include "Cello.h"

int main(int argc, char** argv) {

  /* Stack objects are created using "$" */
  var i0 = $(Int, 5);
  var i1 = $(Int, 3);
  var i2 = $(Int, 4);

  /* Heap objects are created using "new" */
  var items = new(Array, Int, i0, i1, i2);

  /* Collections can be looped over */
  foreach (item in items) {
    print("Object %$ is of type %$\n",
      item, type_of(item));
  }

  /* Heap objects destructed via Garbage Collection */
  return 0;
}

Cello is a library that brings higher level programming to C.

By acting as a modern, powerful runtime system Cello makes many things easy that were previously impractical or awkward in C such as:

• Generic Data Structures
• Polymorphic Functions
• Interfaces / Type Classes
• Constructors / Destructors
• Optional Garbage Collection
• Exceptions
• Reflection

And because Cello works seamlessly alongside standard C you get all the other benefits such as great performance, powerful tooling, and extensive libraries.

---

#include "Cello.h"

int main(int argc, char** argv) {

  /* Shorthand $ can be used for basic types */
  var prices = new(Table, String, Int);
  set(prices, $S("Apple"),  $I(12)); 
  set(prices, $S("Banana"), $I( 6)); 
  set(prices, $S("Pear"),   $I(55));

  /* Tables also support iteration */
  foreach (key in prices) {
    var val = get(prices, key);
    print("Price of %$ is %$\n", key, val);
  }

  return 0;
}

Articles

Learning Resources.

• Installation
• Cello World
• Quickstart
• Common Queries / Pitfalls

Articles about its creation and internal workings.

• Hacking C for fun and Learning (30 min talk)
• Best Improvements of Cello 2.0
• A Fat Pointer Library
• Cello vs C++ vs ObjC
• Benchmarks
• Garbage Collection

---

#include "Cello.h"

int main(int argc, char** argv) {

  var items = new(Array, Int, 
    $I( 8), $I( 5), $I(20), 
    $I(15), $I(16), $I(98));

  /* Iterate over indices using "range" */
  foreach (i in range($I(len(items)))) {
    print("Item Range %i is %i\n", i, get(items, i));
  }

  /* Iterate over every other item with "slice" */ 
  foreach (item in slice(items, _, _, $I(2))) {
    print("Item Slice %i\n", item);
  }

  return 0;
}

---

#include "Cello.h"

/* Define a normal C structure */
struct Point {
  float x, y;
};

/* Make it compatible with Cello */
var Point = Cello(Point);

int main(int argc, char** argv) {

  /* Create on Stack or Heap */
  var p0 = $(Point, 0.0, 1.0);
  var p1 = new(Point, $(Point, 0.0, 2.0));

  /* It can be shown, compared, hashed, etc...
  **
  ** p0: <'Point' At 0x000000000022FC58>
  ** p1: <'Point' At 0x00000000004C7CC8>
  ** cmp: 1
  ** hash: 2849275892l
  */ 
  print("p0: %$\np1: %$\ncmp: %i\nhash: %ul\n",
    p0, p1, $I(cmp(p0, p1)), $I(hash(p0)));

  /* And collected by the GC when out of scope */
  return 0;
}