Added project summary to readme

README.md

@@ -1,4 +1,115 @@
 # Klang - The Kaiser language
 This is the project for Klang - the Kaiser language.
 
-0 is false
+# Authors
+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`
+
+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 buildy the compiler
+- `make clean` cleans up all generated output
+- `make` generated 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;
+}
+
+```
+