Mkdirs/simpleton

Simple scripting language

Simpleton

Simpleton is a basic scripting language I made for fun.
It can run simple CLI programs.

Getting Started

• VSCode Extension
• Variable Declaration
• Variable Assignment
• Operations
• Control Structures
• Functions
• Example

VSCode Extension

If you want syntax highlighting in VSCode go here and follow the instructions.

Variable Declaration

When declaring a variable your line must match the following syntax:
let name:type

Where type is either int, float, string, char or bool.

NOTE: You can also give a value when declaring a variable.
let name:type = value

When doing so, the type can be inferred.
let name = value

WARNING: The language cannot infer the value null since it has no real type.
let name = null

Variable Assignment

As you may have seen, assigning a value to a variable is pretty simple:
name = value

Of course, name must be declared beforehand.
Also, value must either be null or match the type of name.

Operations

The operations supported on the types are:

• + Plus

  • string + string returns the concatenation of two strings.
  • int + int
  • float + float
  • int + float (or float + int) will always return a float.

• - Minus

  • int - int
  • float - float
  • int - float (or float - int) will always return a float.
  • -int (or -float)

• * Star

  • int * int
  • float * float
  • int * float (or float * int)

• / Divide

  • int / int will return the integer part of the result.
  • float / float
  • int / float (or float / int)

• % Modulo

  • int % int will return the remainder of the division between two integer.

• && And

  • bool && bool

• || Or

  • bool || bool

• ! Not

  • !bool

• == Equality

  • string == string
  • char == char
  • int == int
  • float == float
  • bool == bool

• != Inequality

  • string != string
  • char != char
  • int != int
  • float != float
  • bool != bool

• > Greater Than

  • int > int
  • float > float
  • char > char returns if the first char comes after the second.

• >= Greater Than Or Equals To

  • int >= int
  • float >= float
  • char >= char

• < Lower Than

  • int < int
  • float < float
  • char < char returns if the first char comes before the second.

• <= Lower Than Or Equals To

  • int <= int
  • float <= float
  • char <= char

Control Structures

• If branch

The syntax for if block is simple:

if(expression) then {
  ...
  code
  ...
}

• Else branch

Add an else branch to your if like this:

if(expression) then {
  ...
  code
  ...
}else do{
  ...
  code
  ...
}

• Else-If branch

There is no keyword or special way to make else-if branches.
The way to simulate that is to nest an if branch in an else branch:

if(expression) then{
  ...
  code
  ...
} else do{
  if(expression) then {
    ...
    code
    ...
  }
}

• While loop

The syntax is also very simple:

while(expression) do {
  ...
  code
  ...
}

• For loop

for (initialization, condition, statement) do {
  ...
  code
  ...
}

Example: printing n times "Hello world"

def function spam(n:int) : void do {
  for(let i = 0, i < n, i = i+1) do {
    print("Hello world")
  }
}

spam(100)

Functions

To declare a function you must follow this syntax:

def function name(param1:type, param2:type...) : return_type do {
  ...
  code
  ...
  return value
}

If your function returns nothing, put void as the return type.

Example: a function that compares 2 integers.

def function compare(a:int, b:int) : int do{
  if(a < b) then{
    return -1
  }else{
    if(a > b) then {
      return 1
    }else{
      return 0
    }
  }
}

Use the syntax below to call a function:
name(arg1, arg2, ..., argn)

Example:
compare(10, 20)

Some built-in functions are provided:

print(expression)
This will print the value of expression on the standard output.

input(prompt)
This will print prompt on the standard output and return a value from the standard input.

NOTE:
prompt is a string and the function returns a string.

Examples

Hello world program

print("Hello world")

Greet the user

let name = input("What is your name?: ")
let greeting : string = "Hello "+name+" !"
print(greeting)

FizzBuzz

let number = 1
let msg:string
while(number <= 10) do{
  msg = ""
  
  if(number % 3 == 0) then {
    msg = "Fizz"
  }else do{
    if(number % 5 == 0) then {
      msg = "Buzz"
    }
  }

  if(number % 15 == 0) then {
    msg = "FizzBuzz"
  }

  if(msg == "") then {
    print(number)
  }else do {
    print(msg)
  }

  number = number+1
}