Philip-code(TM)

Philip-code(TM) or just pcode, is my own dialect of pseudo-code which I use for the “Computer programming — and so can you!” series.

It has the standard operators +,-,*,/ and so on.

Apart from those it consists of:

• var: a variable declation, consists of var [name] : [typename]
• <=: variable assignment. For example: x <= 10. Assign 10 to x.
• {} : defines a list. For example {1,2,3} is the list containing 1,2 and 3.
• If … then … else … end if: If a condition is true execute the code after then, if not, execute the code after else. For example:
  If i > 2 then
print(“I was greater than 2”)
else
print("I was less than or equal to 2")
End if
• For: A for loop which assigns a variable and every time the loop runs it increments that variable. The loop runs for as long as a condition is true. For example For i <= 0, i<10, i<=i+1 … End For. This assigns the variable the value 0, runs as long as i < 10, and every time the loop runs it assigns i the value i+1.
• mod The modulo operator, returns the remainder after integer division. For example: 5 mod 2 = 1 because 5/2=2 (integer division).
• (…) The n-tuple. For example (1,2) is a 2-tuple consisting of 1,2 (a pair). The idea of a pair can be extended to the n-tuple, for example (4,3,6,3,30) is a 5-tuple. Is declared as var t : Tuple<int,int,int,int,in>. To get an item out of a tuple index it like a list: t[2]. A tuple is just a collection of variables that always go together.
• Func: Declares a function. For example: Func f(i : int, s : string) :String is a function taking two arguments/parameters called i of type integer and s of type string and the return type is a string. To return a value from a function, use the return keyword.

An example of pcode which is meant to be self-explanatory (with the comments).

# Philip-code(TM) - This is a comment, which is ignored
var i : Integer # Declares a variable i of the type Integer
var s : String # Declares a variable s of the type String
var j : Integer
var list : List<Integer> # List of integers
s <= "Hello" # <= is the assignment operator. It assigns "Hello" to             
             # s in this case.
i <= 10      # Assigns 10 to i
list = {10,20,30,40,50,60,70,80,90,100}
# This is a for loop where j starts at 0,it runs as long as j<10, 
# and every time the loop reaches the end j is increased by 1 
# (incremented).
For j <= 0, j < 10, j<=j+1 
  print("J is: ")                                                                
  print(j)
  
  # mod is the modulo operator giving the remainder of division. 
  # sometimes written as %
  
  if j mod 2 = 0 then 
    print("j is even")
  else 
    print("j is odd") 
  end if
  print("List at this position: ")
  print(list[j])
End For
Func addNumbers(i : int, j : int) : int
  return i + j
End func