Comments for Andrew Birkett's blog http://www.nobugs.org/blog Thoughts of a software engineer Fri, 12 Mar 2010 14:56:25 +0000 http://wordpress.org/?v=2.8.4 hourly 1 Comment on Model Checking by Árni Hermann http://www.nobugs.org/blog/archives/2010/03/11/model-checking/comment-page-1/#comment-61699 Árni Hermann Fri, 12 Mar 2010 14:56:25 +0000 http://www.nobugs.org/blog/?p=361#comment-61699 Great! I absolutely recommend it. Although I find there are much nicer modeling languages than SMV, e.g. SPIN, CCS or Rebeca (actor based modeling language). Great! I absolutely recommend it. Although I find there are much nicer modeling languages than SMV, e.g. SPIN, CCS or Rebeca (actor based modeling language).

]]> Comment on Why do they call it: Referentially transparent by Greg McIntyre http://www.nobugs.org/blog/archives/2008/11/12/why-do-they-call-it-referentially-transparent/comment-page-1/#comment-61672 Greg McIntyre Thu, 11 Mar 2010 13:19:29 +0000 http://www.nobugs.org/blog/?p=175#comment-61672 Hurray for this blog entry. *like button* Hurray for this blog entry. *like button*

]]> Comment on Why do they call it: Referentially transparent by ajs http://www.nobugs.org/blog/archives/2008/11/12/why-do-they-call-it-referentially-transparent/comment-page-1/#comment-61661 ajs Thu, 11 Mar 2010 02:14:40 +0000 http://www.nobugs.org/blog/?p=175#comment-61661 Well, Quine was talking about natural language and its relation to philosophy, but he also wrote about logic and philosophy. In particular, your "contexts" are functions, in the mathematical sense. (Note that if "x is blah" and "y is blah" is the same sentence, then x is y, as a string of symbols.) Equivalently, they're formulae/proofs, in a logic of some kind. You sort of skimmed over that part, but acknowledged it -- the semantics of interpretation (the part where you check if the sentence you constructed from a context and value "is true") remain the same under substitution of equivalents. That's it. This is the connection. Functional programming languages have a different model of interpretation, but it's not so different from a proof language. The biggest difference is the mechanism used to quantify over objects by property. Strongly typed functional languages use primarily use types to categorize objects. Logic languages sort objects by the predicates they satisfy. And these approaches are pretty obviously equivalent. A type represents a set of objects that satisfy some predicates/proofs/functions. It is the extension of a predicate. Heck, both of these approaches are equivalent to constructive set theory, under the same form of trivial transformation. Well, Quine was talking about natural language and its relation to philosophy, but he also wrote about logic and philosophy. In particular, your “contexts” are functions, in the mathematical sense. (Note that if “x is blah” and “y is blah” is the same sentence, then x is y, as a string of symbols.) Equivalently, they’re formulae/proofs, in a logic of some kind. You sort of skimmed over that part, but acknowledged it — the semantics of interpretation (the part where you check if the sentence you constructed from a context and value “is true”) remain the same under substitution of equivalents. That’s it. This is the connection.

Functional programming languages have a different model of interpretation, but it’s not so different from a proof language. The biggest difference is the mechanism used to quantify over objects by property. Strongly typed functional languages use primarily use types to categorize objects. Logic languages sort objects by the predicates they satisfy. And these approaches are pretty obviously equivalent. A type represents a set of objects that satisfy some predicates/proofs/functions. It is the extension of a predicate.

Heck, both of these approaches are equivalent to constructive set theory, under the same form of trivial transformation.

]]> Comment on Coders at Work by Anthony Bailey http://www.nobugs.org/blog/archives/2009/10/28/coders-at-work/comment-page-1/#comment-60296 Anthony Bailey Sun, 10 Jan 2010 12:43:12 +0000 http://www.nobugs.org/blog/?p=316#comment-60296 Mostly asking this here rather than later at work because I will probably forget otherwise... Given your interest in language, have you read the similarly interview-based "Masterminds of Programming" (http://amzn.com/0596515170)? I was going to buy "Coders", but got distracted by the existence of "Masterminds", then wondered about buying that and trading lends with you. Mostly asking this here rather than later at work because I will probably forget otherwise…

Given your interest in language, have you read the similarly interview-based “Masterminds of Programming” (http://amzn.com/0596515170)?

I was going to buy “Coders”, but got distracted by the existence of “Masterminds”, then wondered about buying that and trading lends with you.

]]> Comment on Technical debt (or, mortgages in Haskell) by Simon http://www.nobugs.org/blog/archives/2009/11/17/technical-debt-or-mortgages-in-haskell/comment-page-1/#comment-59591 Simon Mon, 07 Dec 2009 23:54:59 +0000 http://www.nobugs.org/blog/?p=326#comment-59591 Very interesting, thanks! Will have to see if there are synergies with hledger. Very interesting, thanks! Will have to see if there are synergies with hledger.

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