Convert WHILE/GOTO/LOOP programs to C

This 'transpiler' will convert WHILE/GOTO/LOOP programs to C source code. It systematically replaces the keywords with the corresponding C syntax and adds some additional checks.

It is meant for demonstration and educational purposes only.

Limitations:

• It will NOT check for any syntactical errors and assumes that the source file is valid according to the syntax below
• The result of the subtraction operation cannot be negative. subtract(5, 7) = max(0, (5-7))
• Variables can overflow. If this happens, the program execution stops.

Syntax:

where n of xn,Mn is a natural number; c is an integer constant

WHILE xn =/= 0 DO <program> END
LOOP xn DO <program> END
IF xn = c THEN GOTO Mj
<program> ; <program>
xn := xm + c
xn := xm - c
Mn: <program>    ---    Markers can be placed at the beginning of lines, however they optional.
# <Comment>

When the program halts, it will output the value of the variable x0. You can mix WHILE, LOOP, GOTO as you like.

Usage

Put your WHILE/GOTO/LOOP program code in a text file.

./wgl.sh <input-file>
gcc <input-file>.c -o out
./out

See the Makefile for usage details.

The program works with the GNU version of sed. It has not been tested with other versions of sed (eg. BSD).

Examples

See examples folder for code examples.