Transpiler from the Top programming language to javascript, written in python3.5.

The Top programming language, also known as Toplang is a functional, staticly-typed and procedural programming language. The language depends on hindley milner type inference to infer most types. Top is aimed at enabling reactive, reusable, reliable web apps running in the browser and the server using the same language.

1. Clone this repo
2. Cd into the downloaded clone
3. Call 'python3 setup.py install'

1. Open up terminal or command prompt`
2. Cd into the directory you wish to create the project folder in.
3. Execute topc new project HelloWorld, this will create a new top project in the current directory
4. Execute cd HelloWorld, this will go into the project directory
5. Execute topc new package main, this will create a new main package inside the src directory, which will contain a port.json file for configurations, the main package and it the entry point to your application
6. Execute topdev 8080, this will start a live reloading build server, that can be viewed at port 8080
7. Open up any web browser with the url 127.0.0.1:8080, the result should be a blank page
8. Create a new file called TopCompiler/main/main.top, then add the filename main to the port.json file in the package directory under the files property, the files property lists in which order the package files should be compiled in.

Like many functional programming languages, blocks in Top are delimited by whitespace. Indenting blocks are required to be with spaces and not tabs to facilitate platform independence. In addition, newlines end statements if the expression is not further indented and no unclosed parenthesis.

Function must called without parenthesis, the function call will then end following the normal statement ending rule

func 10, 5

While in javascript, this is perfectly normal

func(10,5) + 89

In top you should instead write, because otherwise you would be passing the tuple (10,5) plus 89 to func

(func 10, 5) + 80

Once the topdev server is running all you have to do recompile, is save the file. The web page you have open immediately update, however if the compiler catches a compile error a blue box with the error message will be shown below.

Integers are the same as in javascript, however they may contain underscores to make them more readable.

1_000_000

Their type signature is written as int.

Floats can have underscores as Integers and must have a dot in the middle or end with an f.

3.51296
9f

Float's type signature is float.

Boolean can only have two values: true or false.

Strings look the same as javascript strings and have the same methods.

"hello toplang"

However strings can also be interpolated with an expression inside the braces as long as they have a toString method.

"fib(20) = {6765}"

Their type signature is string

The none type is a type and a value none, it represents the absence of a value like void in java.

The syntax for defining functions is the def keyword followed by the function name and opening paranthesis then list the arguments followed by a colon and the argument type seperated by a comma, followed by a closing paranthesis the return type, if no return type is specified the return type of the function is none and then = or do.

Functions defined with = must be pure and cannot perform any side effects.

def add(a: int, b: int) int =
  a + b

Functions defined with do can perform side effects and are compiled into state machines, which won't block on async operations simmilar to async in C#. This means it is unneccesarry to use callback style for asynchronous operations.

import "http"

def getFile(name: string) string do
  http.get name //won't block main thread