EBCompiler 0.1.3

Existential Boolean Compiler

Compiles simple statements of existence and boolean truth into valid SQL (i.e. for check constraints).

Example

Input:

(!is_dled && file_size!?) || (is_dled && file_size?)

Output:

(is_dled IS FALSE AND file_size IS NULL) OR (is_dled IS TRUE AND file_size IS NOT NULL)

Syntax

A name (i.e. variable or column name) can have a variety of unary operators applied to it. A name can only start with a letter but can otherwise contain letters, numbers and underscores.

• no operator is interpreted IS TRUE

• ! becomes IS FALSE

• ? becomes IS NOT NULL

• !? becomes IS NULL

Other than that, you may use logical binary operators (&&, ||) and parenthesis ((, )).

If your input doesn’t follow these rules, there is no guarantee valid SQL will be generated.

Why?

Because I wanted to play around with writing a simple lexer. Also, it allows for writing SQL check constraints more easily.

Q: Wait, that’s really not that sophisticed is it? A: Nope. Pretty trivial.