This code was in equal parts developed by Dennis Kaiser and Marvin Kaiser at the RheinMain University of Applied Sciences for the Compilers course.

Usage

Pass source code via stdin

example call to print help java -cp target/klang-1.0-jar-with-dependencies.jar de.hsrm.compiler.Klang.Klang -h

Arguments:

-h Print this help
--evaluate: Evaluates the given source code
--pretty: Pretty print the given source code
--no-compile: Do not compile the source code
--no-main: Do not generate main function, will be generated as 'start'. Useful for testing

The makefile can be used to perform various functions more easily:

make build simply builds the compiler
make clean cleans up all generated output
make generates code.s from code.k in root folder
make pretty prettifies code.k and writes to pretty.k
make eval evaluates code.k
make test runs tests from src/test/
make cleanTests cleans files generated from tests

Functionality

The KLang compiler supports generation of AMD64 assembly code, as well as prettifying and evaluating the KLang code.

Data Types

Integer

Simple Expressions

The following simple expressions are supported. Expressions need to be put in paranthesis. When using comparison operators, the expressions evaluate to 0 for false and 1 for true.

Addition (+)
Subtraction (-)
Multiplication (*)
Division (/)
Modulo (%)
Equality (==)
Less Than (<)
Less Than Or Equal (<=)
Greater Than (>)
Greater Than Or Equal (>=)
Number Negation (-)

Examples:

(5 + 4)
(8 % 2)
(8 == 0)

Functions

Functions can be defined and called. A function call can be used like any other expression. Recusion is supported

Examples

function fun(x, y, z) {
  return x;
}

fun(1, 2, 3);

Statements

Several statements are supported:

if
variable declaration
variable assignment
return
while
do while
for

Examples

function example(x, y, z) {
  let a;
  let b = 0;
  if ((x == y)) {
    a = y;
  } else if ((x == z)) {
    a = z;
  } else {
    return b;
  } 
  return a;
}

function whileExample(end) {
  let x = 0;
  while ((x < end)) {
    x = (x + 1);
  }
  return x;
}

function doWhileExample(end) {
  let x = 0;
  do {
    x = (x + 1);
  } while((x < end));
}

function forExample(end) {
  let x = 0;
  for (let i = 0; (i < end); i = (i + 1)) {
    x = (x + 1);
  }
  return x;
}