This is a sequence of calculators which can be used to dive into ANTLR.

## calc

Write down the grammar. (source code)

## calc 1.5

Add the main subroutine to use generated lexer and parser. (source code)

## calc 2

Add actions and returns to actually calculate. (source code)

## calc 3

Move from int to double. (source code)

## calc 4

Add custom error reporting. (source code)

## calc 5

Generate AST and then use TreeWalker. (source code)

## calc 6

Replace System.out.println with string templates. (source code)