EBCompiler 0.1.3

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

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.