substructural-types on Mature Pessimizations - A programming blog by Theodoros Chatzigiannakis

Applications of substructural typing

Mon, 06 Mar 2017 20:00:00 +0300

In a previous writing, we mentioned a family of types called substructural types. A type is substructural if it disallows any of the three structural rules: contraction (the ability to use a variable more than once), weakening (the ability to leave a variable unused), and exchange (the ability to reorder usages of two variables with respect to their declaration order).

In this writing, we will look at several problems that substructural type systems can help us solve at compile time, in ways that common unrestricted type systems are simply unable to do.

Structural rules and substructural logics

Mon, 06 Feb 2017 20:00:00 +0300

There is a family of unusual type systems called substructural type systems. Many programmers have never encountered them, while other have encountered them without realizing what they are or what’s the idea behind them.

We will try to shed some light on where substructural type systems come from, by giving a quick tour of their theoretical background, which comes from sequent calculus. To keep this short enough, we will go only over the parts that are useful for examining type systems.