Main Bison cheat.

It is hard to test Bison without Flex, so they are used together.

Information on Flex is not given here.

This generates a simple C-like calculator which supports:

• print statement
• + - * /
• < > <= >= == !=
• variables
• if, while

The program takes output from stdin, and outputs printed results to stdout.

Sample input:

i = 0;
while (i < 3) {
    print i;
    i = i + 1;
}

Output:

0
1
2

Many input examples can be found in the test file.

Possible outputs:

• interpreter
• assembler
• visual ASCII syntax tree

Missing features:

• integers arithmetic only
• functions
• strings

This was taken this from a very good intro source:

Tom Niemann - Lex & Yacc Tutorial

and only minor modifications were made, mostly annotations to explain what lines are doing.