The Ape Programming Language
Try Ape in your browser on Ape Playground.
About
Ape is an easy to use programming language and library written in C. It's an offspring of Monkey language (from Writing An Interpreter In Go and Writing A Compiler In Go books by Thorsten Ball), but it evolved to be more procedural with variables, loops, operator overloading, modules, and more.
Current state
It's under development so everything in the language and the api might change.
Example
fn contains_item(to_find, items) {
for (item in items) {
if (item == to_find) {
return true
}
}
return false
}
const cities = ["Warszawa", "Rabka", "Szczecin"]
const city = "Warszawa"
if (contains_item(city, cities)) {
println(`found ${city}!`)
}Embedding
Add ape.h and ape.c to your project and compile ape.c with a C compiler before linking.
#include "ape.h"
int main() {
ape_t *ape = ape_make();
ape_execute(ape, "println(\"hello world\")");
ape_destroy(ape);
return 0;
}An example that shows how to call Ape functions from C code and vice versa can be found here.
Language
Ape is a dynamically typed language with mark and sweep garbage collection. It's compiled to bytecode and executed on internal VM. It's fairly fast for simple numeric operations and not very heavy on allocations (custom allocators can be configured). More documentation can be found here.
Basic types
bool, string, number (double precision float), array, map, function, error
Operators
Math:
+ - * / %
Binary:
^ | & << >>
Logical:
! < > <= >= == != && ||
Assignment:
= += -= *= /= %= ^= |= &= <<= >>=
Defining constants and variables
const constant = 2
constant = 1 // fail
var variable = 3
variable = 7 // okStrings
const str1 = "a string"
const str2 = 'also a string'
const str3 = `a template string, it can contain expressions: ${2 + 2}, ${str1}`Arrays
const arr = [1, 2, 3]
arr[0] // -> 1Maps
const map = {"lorem": 1, 'ipsum': 2, dolor: 3}
map.lorem // -> 1, dot is a syntactic sugar for [""]
map["ipsum"] // -> 2
map['dolor'] // -> 3Conditional statements
if (a) {
// a
} else if (b) {
// b
} else {
// c
}Loops
while (true) {
// body
}
var items = [1, 2, 3]
for (item in items) {
if (item == 2) {
break
} else {
continue
}
}
for (var i = 0; i < 10; i++) {
// body
}Functions
const add_1 = fn(a, b) { return a + b }
fn add_2(a, b) {
return a + b
}
fn map_items(items, map_fn) {
const res = []
for (item in items) {
append(res, map_fn(item))
}
return res
}
map_items([1, 2, 3], fn(x){ return x + 1 })
fn make_person(name) {
return {
name: name,
greet: fn() {
println(`Hello, I'm ${this.name}`)
},
}
}Errors
const err = error("something bad happened")
if (is_error(err)) {
println(err)
}
fn() {
recover (e) { // e is a runtime error wrapped in error
return null
}
crash("something bad happened") // crashes are recovered with "recover" statement
}Modules
import "foo" // import "foo.ape" and load global symbols prefixed with foo::
foo::bar()
import "bar/baz" // import "bar/baz.ape" and load global symbols prefixed with baz::
baz::foo()Operator overloading
fn vec2(x, y) {
return {
x: x,
y: y,
__operator_add__: fn(a, b) { return vec2(a.x + b.x, a.y + b.y)},
__operator_sub__: fn(a, b) { return vec2(a.x - b.x, a.y - b.y)},
__operator_minus__: fn(a) { return vec2(-a.x, -a.y) },
__operator_mul__: fn(a, b) {
if (is_number(a)) {
return vec2(b.x * a, b.y * a)
} else if (is_number(b)) {
return vec2(a.x * b, a.y * b)
} else {
return vec2(a.x * b.x, a.y * b.y)
}
},
}
}Splitting and joining
ape.c can be split into separate files by running utils/split.py:
python3 utils/split.py --input ape.c --output-path ape
It can be joined back into a single file with utils/join.py:
python3 utils/join.py --template utils/ape.c.templ --path ape --output ape.c
Visual Studio Code extension
A Visual Studio Code extension can be found here.
My other projects
- parson - JSON library
- kgflags - command-line flag parsing library
- agnes - header-only NES emulation library