# Square Root Calculator
# by Martin del Rio
# https://www.ldpl-lang.org/ 
# Created for LDPL 1.0

DATA:
# Square-root sub-procedure
sqrt/radicand is number
sqrt/result is number
sqrt/aux is number
sqrt/last-value is number

PROCEDURE:
# Ask for a number
display "Enter a number: "
accept sqrt/radicand

# Declare square root subprocedure
# Calculates the square root of a radicand using the babylonian method
# Input parameter:
# - sqrt/radicand: the number to be square-rooted (preserved)
# Output parameter:
# - sqrt/result: the square root of the given number
sub-procedure square-root
    if sqrt/radicand is equal to 0 then
        store 0 in sqrt/result
        return
    end if
    store 0 in sqrt/last-value
    store 1 in sqrt/result
    while 1 is equal to 1 do
        in sqrt/aux solve sqrt/radicand / sqrt/result
        in sqrt/result solve sqrt/aux + sqrt/result
        in sqrt/result solve sqrt/result / 2
        if sqrt/result is not equal to sqrt/last-value then
            store sqrt/result in sqrt/last-value
        else
            break
        end if
    repeat
end sub-procedure

# Calculate square root of the entered number
call sub-procedure square-root
display "sqrt(" sqrt/radicand ") = " sqrt/result crlf