Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #8007

Re: new Java lambda syntax

Show key headers only | View raw

On 9/13/2011 3:29 PM, Tom Anderson wrote:
> Basically, lambdas can be either method-like (they return values from
> themselves) or statement-like (they return values from their enclosing
> methods). Lambdas are method-like in all the current dynamic languages
> (AFAIK - they certainly are in Smalltalk, Python and Javascript).

As I recall, Smalltalk lambdas were actually discrete blocks (Smalltalk 
has (almost? [1]) no control structure primitives, and I distinctly 
recall them allowing non-local control flow, since actual structures as 
we know them in Java and its ilk don't exist. Python's lambdas are 
single expressions (in a language that distinguishes between expressions 
and statements), so it can't really be classified as statement-like or 
method-like easily. JavaScript actually doesn't have lambdas [2], it 
just has first-class functions that can be defined anywhere.

A more natural breakdown of lambdas, or at least clearer, is on whether 
or not the lambdas are designed primarily for thunking expressions 
(e.g., the parameter to a sort method), or if they are designed for 
implementing control structure.

[1] My only exposure to Smalltalk was in my software engineering class 
(don't ask), so we never really discussed any implications of its 
functional paradigm.
[2] Actually, distinguishing between a lambda and a function is 
sometimes difficult and perhaps pointless. The basic definition I'm 
using here is meaningful only for object-oriented languages, and it's 
the question of does `this' (or equivalent) refer to the same `this' as 
in the enclosing scope or not. JS doesn't support OO in the classical 
way, and how `this' gets resolved is actually handled by the way you 
call the method. Another metric is whether or not the syntax of defining 
a lambda is the same as a regular method call.

-- 
Beware of bugs in the above code; I have only proved it correct, not 
tried it. -- Donald E. Knuth

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

new Java lambda syntax markspace <-@.> - 2011-09-08 13:19 -0700
  Re: new Java lambda syntax Roedy Green <see_website@mindprod.com.invalid> - 2011-09-08 15:18 -0700
    Re: new Java lambda syntax Arne Vajhøj <arne@vajhoej.dk> - 2011-09-08 18:27 -0400
    Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-08 15:40 -0700
      Re: new Java lambda syntax Arne Vajhøj <arne@vajhoej.dk> - 2011-09-08 19:27 -0400
        Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-08 16:29 -0700
          Re: new Java lambda syntax Arne Vajhøj <arne@vajhoej.dk> - 2011-09-08 19:48 -0400
          Re: new Java lambda syntax Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-09-08 17:56 -0700
            Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-08 22:23 -0700
    Re: new Java lambda syntax "Nasser M. Abbasi" <nma@12000.org> - 2011-09-08 16:41 -0700
    Re: new Java lambda syntax Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-08 20:50 -0500
  Re: new Java lambda syntax bugbear <bugbear@trim_papermule.co.uk_trim> - 2011-09-09 09:33 +0100
  Re: new Java lambda syntax Tom Anderson <twic@urchin.earth.li> - 2011-09-10 14:48 +0100
    Re: new Java lambda syntax Steven Simpson <ss@domain.invalid> - 2011-09-10 16:17 +0100
      Re: new Java lambda syntax Tom Anderson <twic@urchin.earth.li> - 2011-09-11 13:06 +0100
        Re: new Java lambda syntax Steven Simpson <ss@domain.invalid> - 2011-09-11 17:18 +0100
          Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-11 11:08 -0700
            Re: new Java lambda syntax Steven Simpson <ss@domain.invalid> - 2011-09-11 20:14 +0100
              Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-11 14:08 -0700
              Re: new Java lambda syntax Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-11 17:07 -0500
                Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-11 16:18 -0700
                Re: new Java lambda syntax Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-09-13 02:00 +0200
                Re: new Java lambda syntax Arne Vajhøj <arne@vajhoej.dk> - 2011-09-12 20:59 -0400
                Re: new Java lambda syntax Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-12 21:24 -0500
                Re: new Java lambda syntax Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-09-13 21:04 +0200
                Re: new Java lambda syntax Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-13 15:22 -0500
                Re: new Java lambda syntax Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-09-13 23:25 +0200
                Re: new Java lambda syntax Tom Anderson <twic@urchin.earth.li> - 2011-09-13 21:29 +0100
                Re: new Java lambda syntax Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-09-13 23:26 +0200
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-13 20:25 -0400
                Re: new Java lambda syntax Tom Anderson <twic@urchin.earth.li> - 2011-09-15 21:58 +0100
                Re: new Java lambda syntax Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-13 21:36 -0500
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-13 22:49 -0400
                Re: new Java lambda syntax "supercalifragilisticexpialadiamaticonormalizeringelimatisticantations" <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-14 02:49 -0400
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-14 03:01 -0400
                Re: new Java lambda syntax "winkleMeister" <..00@00.00.00.1> - 2011-09-14 09:59 +0000
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-15 10:16 -0400
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-14 06:40 -0400
                Re: new Java lambda syntax supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-09-15 10:16 -0400
                Re: new Java lambda syntax lightworker <etts@0n.org.null> - 2011-09-16 01:57 +0000
                Re: new Java lambda syntax thoolen <th00len@th0lenbot.thorium> - 2011-09-15 22:41 -0400
                Re: new Java lambda syntax Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-09-14 06:29 -0300
                Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-14 07:40 -0700
                Re: new Java lambda syntax Lew <lewbloch@gmail.com> - 2011-09-14 08:01 -0700
                Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-14 14:50 -0700
                Re: new Java lambda syntax Lew <lewbloch@gmail.com> - 2011-09-14 18:02 -0700
                Re: new Java lambda syntax BGB <cr88192@hotmail.com> - 2011-09-14 21:08 -0700

csiph-web