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List out of Lambda

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Re: List out of Lambda

#2

Post by TeeWEE »

For people who are interested. The theoretical foundations for this is lambda-calculus created by Alonso Church.

Encoding integers with lambda is called the curch encoding: http://en.wikipedia.org/wiki/Church_numerals

Functional programming in general is built upon the foundations laid out by him.

Actually the domainname of hackernews (ycombinator) has a lot todo with lambda calculus.

Re: List out of Lambda

#3

Post by Millennium »

Turing-completeness, of course. After that, it's all a matter of allowing you to stay as focused as possible on the task at hand: some reasonable way to express your chosen paradigm, library support for things ancillary to your actual task, and some measure of support in the tools you find useful.

Re: List out of Lambda

#4

Post by sfvisser »

Millennium wrote: post #3

Turing-completeness, of course. After that, it's all a matter of allowing you to stay as focused as possible on the task at hand: some reasonable way to express your chosen paradigm, library support for things ancillary to your actual task, and some measure of support in the tools you find useful.

> Turing-completeness, of course.

Lots of useful programs can be written without turing completeness. It can be useful, but only for a limited problem domain.

Re: List out of Lambda

#5

Post by peter-fogg »

sfvisser wrote: post #4
Millennium wrote: post #3

Turing-completeness, of course. After that, it's all a matter of allowing you to stay as focused as possible on the task at hand: some reasonable way to express your chosen paradigm, library support for things ancillary to your actual task, and some measure of support in the tools you find useful.

> Turing-completeness, of course. Lots of useful programs can be written without turing completeness. It can be useful, but only for a limited problem domain.

It actually can have some benefits -- a language without any unbounded loops or recursion isn't Turing-complete, but you do get a static guarantee of termination. NASA, for example, writes much of their C code only with bounded recursion. So they can't compute some things, but they can be sure that the Mars lander never gets stuck in an infinite loop.

Re: List out of Lambda

#6

Post by arethuza »

TeeWEE wrote: post #2

For people who are interested. The theoretical foundations for this is lambda-calculus created by Alonso Church. Encoding integers with lambda is called the curch encoding: http://en.wikipedia.org/wiki/Church_numerals Functional programming in general is built upon the foundations laid out by him. Actually the domainname of hackernews (ycombinator) has a lot todo with lambda calculus.

All you need is S and K - all the rest is syntactic sugar, even Y.

:-)

Re: List out of Lambda

#7

Post by McUsr »

Seriously, what I need in a programming language depends on what I intend to achieve with it.

I use blocks in Objective-C and "closures" in Applescript.

    to lambda(aStatment)
    	script intern
    		say aStatment
    	end script
    end lambda
    set a to lambda("applescript…")
    set b to lambda("knows how to …")
    set c to lambda("make a closure if not a lambda…")
    tell a to run
    tell b to run
    tell c to run

Re: List out of Lambda

#8

Post by arethuza »

sfvisser wrote: post #4
Millennium wrote: post #3

Turing-completeness, of course. After that, it's all a matter of allowing you to stay as focused as possible on the task at hand: some reasonable way to express your chosen paradigm, library support for things ancillary to your actual task, and some measure of support in the tools you find useful.

> Turing-completeness, of course. Lots of useful programs can be written without turing completeness. It can be useful, but only for a limited problem domain.

"Lots of useful programs can be written without turing completeness."

Including Bitcoin transactions - I learned this from elsewhere on HN today.

FYI: https://en.bitcoin.it/wiki/Script

Re: List out of Lambda

#10

Post by masklinn »

TeeWEE wrote: post #2

For people who are interested. The theoretical foundations for this is lambda-calculus created by Alonso Church. Encoding integers with lambda is called the curch encoding: http://en.wikipedia.org/wiki/Church_numerals Functional programming in general is built upon the foundations laid out by him. Actually the domainname of hackernews (ycombinator) has a lot todo with lambda calculus.

And for a pretty nice demonstration of (untyped) lambda calculus, http://codon.com/programming-with-nothing
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