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Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Ben Coman

On Sun, Oct 16, 2016 at 9:11 PM, Charlie Robbats <charlie.robbats(a)gmail.com> wrote: > Here, Dmitry, try this code in playground...maybe helps you understand > > | lookupClosure | > lookupClosure := []. > lookupClosure := [:cls :selector | > (cls == nil) > ifTrue: [Warning signal: ('selector lookup failure: ', selector)]. > (cls methodDictionary > at: selector > ifAbsent: [nil]) > ifNil: [lookupClosure value: cls superclass value: selector] > ifNotNil: [:meth | Smalltalk tools browser openOnMethod: meth]]. > lookupClosure value: Array value: #at:put:. Nice example. Slightly improved... | lookupClosure | lookupClosure := []. lookupClosure := [:cls :selector | (cls == nil) ifTrue: [Warning signal: ('selector lookup failure: ', selector)]. cls methodDictionary at: selector ifPresent: [:meth | Smalltalk tools browser openOnMethod: meth] ifAbsent: [lookupClosure value: cls superclass value: selector]]. lookupClosure value: Array value: #at:put:. cheers -ben

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by CodeDmitry

Thanks! That works! (And I learned that I can create collections with {a. b. c} syntax). -- View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Charlie Robbats

Here, Dmitry, try this code in playground...maybe helps you understand | lookupClosure | lookupClosure := []. lookupClosure := [:cls :selector | (cls == nil) ifTrue: [Warning signal: ('selector lookup failure: ', selector)]. (cls methodDictionary at: selector ifAbsent: [nil]) ifNil: [lookupClosure value: cls superclass value: selector] ifNotNil: [:meth | Smalltalk tools browser openOnMethod: meth]]. lookupClosure value: Array value: #at:put:. On 10/16/2016 8:27 AM, CodeDmitry wrote: > I define Magic as "An opaque abstraction or an abstraction you think is > opaque until you learn better.", to a beginner, everything is deeply > Magical. > > That said, much of Smalltalk's opaqueness is not due to the language, but > due to me being a beginner. I'm sure there's a way to actually force sending > a message to a dictionary via something like dict['at:put:']('foo', 'bar') > but I am not familiar enough with Smalltalk to express it, so it feels like > the only way to send a message is via this multi-part message abstraction. > > > > > > > -- > View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Ben Coman

On Sun, Oct 16, 2016 at 8:38 PM, Nicolai Hess <nicolaihess(a)gmail.com> wrote: > Am 16.10.2016 14:35 schrieb "CodeDmitry" <dimamakhnin(a)gmail.com>: >> >> I define Magic as "An opaque abstraction or an abstraction you think is >> opaque until you learn better.", to a beginner, everything is deeply >> Magical. >> >> That said, much of Smalltalk's opaqueness is not due to the language, but >> due to me being a beginner. I'm sure there's a way to actually force >> sending >> a message to a dictionary via something like dict['at:put:']('foo', 'bar') >> but I am not familiar enough with Smalltalk to express it, so it feels >> like >> the only way to send a message is via this multi-part message abstraction. >> > > You can always access the method dict directly to get a method and call > "perform" or perform with arguments. To put that in more concrete terms... a := Array new: 1. a perform: #at:put: withArguments: {1. 'Hello, world'}. a inspect. Note how #at:put: is a single identifier. cheers -ben

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Ben Coman

On Sun, Oct 16, 2016 at 12:44 PM, CodeDmitry <dimamakhnin(a)gmail.com> wrote: > I understand that it is a single message send, but to know how to handle the > message at runtime, the parser needs to somehow determine where the > implementation of that message is. It must do a lookup based on multiple > keys(at, and put), This is wrong :) it is only one key #at:put: Define a method.... test |arr| a := Array new: 1. a at: 1 put: 'Hello, World'. Then in the method pane, right-click and choose Inspect Method, then look at the [Bytecodes] tab. You'll see "28 <C1> send: at:put:" So the parser has already done its part compiling the source code to bytecode and plays no further part in looking up which implementation method to execute in response to the message. That is done by the VM when the message is sent. If you look at the chart at the top of [1], you'll see #interpret calls #dispatchIn:On: which calls #commonOrdinarySend:. This calls #internalFindNewMethodOrdinary which starts the actual method lookup by the VM. To review these methods you need to load the VMMaker package, which the instructions at [2] will do for you. [1] http://forum.world.st/CogVM-Execution-Flow-td4900675.html [2] https://github.com/pharo-project/pharo-vm cheers -ben which is really confusing. "methods" are easy to look up > because they only have one name, but messages have one name which is split > amongst each argument. > > Simple concatenation does not make sense, since {at: x, put: y} and {a: x, > tput: y} are different messages. > > The only way I can think of this being implemented "easily" is by storing a > table of entries {num_args, arg_names, impl_ref}, and then have the function > "send" do a linear search over this table until it finds an entry with > num_args = 2, each arg_name matching the argument name keys in order, and > then calling the impl_ref with the array of values without the names. > > I'm wondering if there is a way to do this without having to loop over every > single message the object has, then every message its' parent object has, > and so on, just to find which function you actually want to call. > > > > > > -- > View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Dimitris Chloupis

Smalltalk does not allow you to do calls of any kind, everything goes through the messaging system . To have the same in another language you will have to disable the ability to call functions and method and replace them with messages. No language such feature not even lisp, the language that excels at manipulating its syntax . In order to implement this you will have to go deep into the implementation of the language and essentially change it to something , probably a new programming language. On Sun, 16 Oct 2016 at 15:35, CodeDmitry <dimamakhnin(a)gmail.com> wrote: > I define Magic as "An opaque abstraction or an abstraction you think is > opaque until you learn better.", to a beginner, everything is deeply > Magical. > > That said, much of Smalltalk's opaqueness is not due to the language, but > due to me being a beginner. I'm sure there's a way to actually force > sending > a message to a dictionary via something like dict['at:put:']('foo', 'bar') > but I am not familiar enough with Smalltalk to express it, so it feels like > the only way to send a message is via this multi-part message abstraction. > > > > > > > -- > View this message in context: > http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Mark Bestley

For an example of a working bridge between the two ways of methods and function see PyObjc which allows Python code to call Objective C messaging (e.g in a similar form to your mapping Javascript to Smalltalk - except Javascript is not class based) https://pythonhosted.org/pyobjc/core/intro.html Mark On 16/10/2016 12:59, Tudor Girba wrote: > Hi, > > >> On Oct 16, 2016, at 10:41 AM, CodeDmitry <dimamakhnin(a)gmail.com> wrote: >> >> I was actually curious about this in Ruby as well, since Ruby also doesn't >> have the Smalltalk message syntax. >> >> I figure that the magic behind it is that Smalltalk takes strings like "dict >> at: 'foo' put: 'bar'" and evaluates them into a JavaScript equivalent of >> "dict['at:put:']('foo', 'bar')â. > > There is no magic. This is how the syntax is. Instead of parentheses that accumulate all parameters in a single place like: > x.atput(a,b); > > we can insert the argument inside the message name, like: > x at: a put: b. > > Itâs not magic, is just different. Thatâs all. Except that one makes it possible to write code that resembles natural language. > > Doru > > > >> Basically, my proof of concept(I cheated with regex to cut time): >> >> 'use strict'; >> >> var Dictionary = function Dictionary() { >> this.dict = {}; >> }; >> Dictionary.prototype['at:put:'] = function(index, value) { >> this.dict[index] = value; >> }; >> Object.defineProperty(Dictionary, 'new', { >> get: function () { >> return new this; >> } >> }); >> >> function st_eval(str) { >> var x = str.match(/(dict)\s+(at):\s+'(foo)'\s+(put):\s+'(bar)'/); >> var target = x[1]; >> var callName = x[2] + ':' + x[4] + ':'; >> var argv = [x[3], x[5]]; >> var realTarget = eval(target); >> realTarget[callName].apply(realTarget, argv); >> } >> >> var dict = Dictionary.new; >> console.log(dict); >> //dict['at:put:']('foo', 'bar'); >> console.log(dict); >> st_eval("dict at: 'foo' put: 'bar'"); >> console.log(dict); >> >> >> >> >> -- Mark

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Nicolai Hess

Am 16.10.2016 14:35 schrieb "CodeDmitry" <dimamakhnin(a)gmail.com>: > > I define Magic as "An opaque abstraction or an abstraction you think is > opaque until you learn better.", to a beginner, everything is deeply > Magical. > > That said, much of Smalltalk's opaqueness is not due to the language, but > due to me being a beginner. I'm sure there's a way to actually force sending > a message to a dictionary via something like dict['at:put:']('foo', 'bar') > but I am not familiar enough with Smalltalk to express it, so it feels like > the only way to send a message is via this multi-part message abstraction. > You can always access the method dict directly to get a method and call "perform" or perform with arguments. > > > > > > -- > View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by CodeDmitry

I define Magic as "An opaque abstraction or an abstraction you think is opaque until you learn better.", to a beginner, everything is deeply Magical. That said, much of Smalltalk's opaqueness is not due to the language, but due to me being a beginner. I'm sure there's a way to actually force sending a message to a dictionary via something like dict['at:put:']('foo', 'bar') but I am not familiar enough with Smalltalk to express it, so it feels like the only way to send a message is via this multi-part message abstraction. -- View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Oct. 16, 2016

Re: [Pharo-users] How do Smalltalk disambiguate messages?

by Tudor Girba

Hi, > On Oct 16, 2016, at 10:41 AM, CodeDmitry <dimamakhnin(a)gmail.com> wrote: > > I was actually curious about this in Ruby as well, since Ruby also doesn't > have the Smalltalk message syntax. > > I figure that the magic behind it is that Smalltalk takes strings like "dict > at: 'foo' put: 'bar'" and evaluates them into a JavaScript equivalent of > "dict['at:put:']('foo', 'bar')â. There is no magic. This is how the syntax is. Instead of parentheses that accumulate all parameters in a single place like: x.atput(a,b); we can insert the argument inside the message name, like: x at: a put: b. Itâs not magic, is just different. Thatâs all. Except that one makes it possible to write code that resembles natural language. Doru > Basically, my proof of concept(I cheated with regex to cut time): > > 'use strict'; > > var Dictionary = function Dictionary() { > this.dict = {}; > }; > Dictionary.prototype['at:put:'] = function(index, value) { > this.dict[index] = value; > }; > Object.defineProperty(Dictionary, 'new', { > get: function () { > return new this; > } > }); > > function st_eval(str) { > var x = str.match(/(dict)\s+(at):\s+'(foo)'\s+(put):\s+'(bar)'/); > var target = x[1]; > var callName = x[2] + ':' + x[4] + ':'; > var argv = [x[3], x[5]]; > var realTarget = eval(target); > realTarget[callName].apply(realTarget, argv); > } > > var dict = Dictionary.new; > console.log(dict); > //dict['at:put:']('foo', 'bar'); > console.log(dict); > st_eval("dict at: 'foo' put: 'bar'"); > console.log(dict); > > > > > > -- > View this message in context: http://forum.world.st/How-do-Smalltalk-disambiguate-messages-tp4918946p4918… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > -- www.tudorgirba.com www.feenk.com âThe smaller and more pervasive the hardware becomes, the more physical the software gets."

Oct. 16, 2016