Scripting language

A simple scripting language writing in F# with FsLexYacc. Main features are:

• Collections
• Boolean algabra
• Controlflow: if, if-else, foreach
• Lexial scoping

Variables

Variables are created with the let keyword:

let x = 5

Variables are mutable:

let x = 5
x = 6

String, bool and int are the supported primitive datatypes:

let string = "a string"
let int = 1
let bool = true

Scoping

This language uses lexial scoping. This will print 4 and 2:

let x = 1
if true then {
  x = 2
  let x = 3
  x = 4
  echo x
}
echo x

Echo

with echo you can print any variable:

let x = 1
echo x
echo "hi"

Collections

Collections are implemented as F# lists. They are created with [ and ]

let col = [1,2,3]

You can mix types in one collection:

let col = [1, "1", true]

Items are accesed by index:

let col = [1,2,3]
let snd = x[1]
x[1] = 5

Iterations

Lists can be iterated with the foreach keyword:

let col = [1,2,3]
foreach item in col {
  echo item
}

Comparision

Values can be compared with !=, ==, < en >. You can only compare variables with the same types. Types will not chance at runtime. Boolean algabra is implemented with || and &&

Conditions

Flowcontrol is implemented with if-statements and if-else-statements. For example:

if 5 == 4 then {
  echo "shouldn't happed"
}

if 5 == 4 then {
  echo "shouldn't happed"
} else {
  echo "should happen"
}