posted on 2002-06-01, 00:00authored byFrank Pfenning
Types were developed in the early part of the 20th century in order to avoid inconsistencies
in Frege’s formulation of logic discovered by Russell. They therefore have a
strong logical origin, confirmed by the development of Church’s type theory, sometimes
called higher-order logic. It contains the simply-typed λ-calculus which is at the core
of most modern programming languages. Through the research of other pioneers such
as Milner and Martin-Löf, type systems are now understood to be central in the design
and analysis of programming languages. They provide the fundamental principles
according to which languages are organized. A thorough textbook on type systems
in programming languages had been long overdue and Pierce’s book provided exactly
that.