Lasagna

Very small stack based language.

Read more here: https://pimpale.github.io/lasagna.html

Compiling

make

Running

This language is based entirely on the stack and string. Some examples:

hello world

(hello world) print

This prints hello world. Instead of ", ( and ) are used to represent strings, and can be nested. The string is pushed onto the stack character by character, with a leading and terminating null byte. printstr is one of a few built in functions defined in src/functions.c

comments

Comments go from a # to the end of the line, and can be defined anywhere (even in a string). To include a literal # in the string, use a backslash

(hello
# This is a comment
world) println

This code would print out:

hello
world

However, if we escape the hash, it would be:

(hello
\# This is a comment
world) println

This results in

hello
# This is a comment
world

if statement

1

( # If
  (if the following condition is true, this will print) println
)
( # Else
  (if not, this will) println
)
ifelse

The ifelse function takes 3 parameters, first a u8 number and two strings to be evaluated. The first string will be evaluated if the number is not equal to zero, and the second string will be evaluated if it was zero. Since strings can be nested, it's not a problem that we have another one inside. In this case, since the 1st parameter of ifelse is 1, the first string is evaluated. This pushes the string "if the following condition is true, this will print" to the stack and then prints it. There is also eval in addition to ifelse that evaluates unconditionally.

math

1 2 +u8 print8

This program pushes the bytes 1 and 2, sums them, and prints the result. The order is left to right. For the most part, math is pretty self explanatory. Numeric literals must be less than 255.

defining a function

In order to define a new word, you'll have to use the mkfun function

((hello) println) (say-hello) mkfun

Make sure that this file is in the current directory. The word definition is instantly available to you with no reload. Type

say-hello

within the interactive prompt. It should print out hello world.

loops

Loops loop forever as long as the value on the stack is not 0. They pop the value of the stack before executing the body.

To print a word 10 times:

10
(
  (a word) println
  1 -u8
  dupu8
) loop

Fizzbuzz:

100
1 ( # loop
  # Although the loop counts down, we must count up
  dupu8
  100 -u8

  dupu8 3 %u8 0 ==u8 dupu8 5 %u8 0 ==u8 &&u8 #if
  (
    (fizz buzz) println
  )
  # Else
  (
    dupu8 3 %u8 0 ==u8 #if
    (
      (fizz) println
    )
    # Else
    (
      dupu8 5 %u8 0 ==u8 #if
      (
        (buzz) println
      ) () ifelse
    ) ifelse
  ) ifelse

  dropu8 # Drop the 100 - version
  1 -u8  # Subtract 1 from counter
  dupu8  # Make copy for loop to consume
) loop