[Pharo-users] can I write this without the three if then;s
--- Begin Message --- Hello, Im trying to solve a challenge from exercism where I have to calculate the points somehow gets on a very simple darts board. I solved it like this : scoreX: anInteger y: anInteger2 | distance | distance := (anInteger squared + anInteger2 squared) sqrt. distance > 10 ifTrue: [ ^ 0 ]. distance > 5 ifTrue: [ ^ 1 ]. distance > 1 ifTrue: [ ^ 5 ]. ^ 10 but now I use three if then and I think it's ugly code. Is there a way I can make it more the smalltalk way ? Regards, Roelof --- End Message ---
Re: [Pharo-users] can I write this without the three if then;s
You might try Magnitude >> between: min and: max -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] can I write this without the three if then;s
--- Begin Message --- Thanks, But it looks to me I still need the ifTrue because the between gives also a true or false. Roelof Op 27-12-2019 om 20:38 schreef tbrunz: You might try Magnitude >> between: min and: max -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html --- End Message ---
Re: [Pharo-users] can I write this without the three if then;s
Hi
First, I think your code is readable and easy to understand.
I think the problem does not lend itself too much towards having “an object
oriented solution”, as such.
If you are looking for a one-liner using smalltalk libraries, you could do:
({10 -> 0. 5 -> 1. 1 -> 5. 0 -> 10} detect: [ :dist | dist key < distance
]) value
but I really think your code is easier to read, which is what I appreciate
the most.
Best,
Kasper
On 27 December 2019 at 20.18.38, Roelof Wobben via Pharo-users (
pharo-users@lists.pharo.org) wrote:
Hello,
Im trying to solve a challenge from exercism where I have to calculate the
points somehow gets on a very simple darts board.
I solved it like this :
scoreX: anInteger y: anInteger2
| distance |
distance := (anInteger squared + anInteger2 squared) sqrt.
distance > 10
ifTrue: [ ^ 0 ].
distance > 5
ifTrue: [ ^ 1 ].
distance > 1
ifTrue: [ ^ 5 ].
^ 10
but now I use three if then and I think it's ugly code.
Is there a way I can make it more the smalltalk way ?
Regards,
Roelof
Re: [Pharo-users] can I write this without the three if then;s
--- Begin Message ---
Hello Kasper
Thanks for the feedback.
I also like readable and easy to understand code but I get the
feeling that it;s good practice to use as minimal as possible if
then's
So I wonder if and how I can achieve that here.
Roelof
Op 27-12-2019 om 20:47 schreef Kasper Østerbye:
Hi
First, I
think your code is readable and easy to understand.
I think
the problem does not lend itself too much towards having “an
object oriented solution”, as such.
If you are
looking for a one-liner using smalltalk libraries, you could do:
({10 ->
0. 5 -> 1. 1 -> 5. 0 -> 10} detect: [ :dist | dist key
< distance ]) value
but I
really think your code is easier to read, which is what I
appreciate the most.
Best,
Kasper
On 27 December 2019 at 20.18.38, Roelof
Wobben via Pharo-users (pharo-users@lists.pharo.org)
wrote:
Hello,
Im trying to solve a challenge from exercism where I
have to
calculate the points somehow gets on a very simple
darts
board.
I solved it like this :
scoreX: anInteger y: anInteger2
| distance |
distance := (anInteger squared + anInteger2
squared) sqrt.
distance > 10
ifTrue: [ ^ 0 ].
distance > 5
ifTrue: [ ^ 1 ].
distance > 1
ifTrue: [ ^ 5 ].
^ 10
but now I use three if then and I think it's ugly
code.
Is there a way I can make it more the smalltalk way
?
Regards,
Roelof
--- End Message ---
Re: [Pharo-users] can I write this without the three if then;s
I would probably set up an array of associations whose keys are the boundary limits and whose values are the target values (ordered, in this example, from outer to inner). Then loop over the array's associations using inject:into:, testing for the point where (each < key), at which point you return the previous association's value. -t -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] can I write this without the three if then;s
Doing it the way I describe above eliminates repetitive if-then statements
('switch' or 'case' statements in other languages, which make for a
maintenance mess), automatically extends for additional rings, doesn't embed
"magic numbers" for defined rings within the decision logic, and takes
advantage of the naturally recursive nature of this kind of graduated
comparison test.
-t
--
Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] can I write this without the three if then;s
You could also accomplish this with a simple 'do:' construct by creating the associations with the the ring limits & points "staggered" (by one level), so that when (each < key) you can return the 'current' association value... Which, now that I'm looking closely at your solution, Kasper, seems to be what you already proposed... Either should work. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
[Pharo-users] uses or instead of a searching literal
--- Begin Message --- Hello, How can I get rid of the above error message with this code : abbreviatePhrase: aString | splitted | splitted := aString splitOn: [ :char | char = Character space or: [ char = $- or: [ char = $_ ] ] ]. ^ String streamContents: [ :stream | splitted reject: [ :word | word isEmpty ] thenDo: [ :word | stream nextPut: word first uppercase ] ] Regards, Roelof --- End Message ---
Re: [Pharo-users] uses or instead of a searching literal
Since you're splitting a String, why not use a Regex to do this? -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Re: [Pharo-users] can I write this without the three if then;s
Myself, I see only one issue in your code, and that is the pointless use of sqrt. scoreX: anInteger y: anInteger2 | radiusSquared | radiusSquared := anInteger squared + anInteger2 squared. radiusSquared > 100 ifTrue: [ ^ 0 ]. radiusSquared > 25 ifTrue: [ ^ 1 ]. radiusSquared > 1 ifTrue: [ ^ 5 ]. ^ 10 Make that two issues. The names anInteger and anInteger2. How about scoreHorizontal: horizontal vertical: vertical ... The OO dogma about "if' that you refer to is about not using "if" to make decisions based on TYPE. Making decisions based on NUMERIC RANGES is perfectly OK. You could introduce a 'HalfOpenRangeDictionary" class [K1,K2) -> V1 [K2,K3) -> V2 ... [Kn,infinity) -> Vn But "You Ain't Gonna Need It", so don't. On Sat, 28 Dec 2019 at 08:18, Roelof Wobben via Pharo-users wrote: > > Hello, > > Im trying to solve a challenge from exercism where I have to calculate the > points somehow gets on a very simple darts board. > > I solved it like this : > > > scoreX: anInteger y: anInteger2 > | distance | > distance := (anInteger squared + anInteger2 squared) sqrt. > distance > 10 > ifTrue: [ ^ 0 ]. > distance > 5 > ifTrue: [ ^ 1 ]. > distance > 1 > ifTrue: [ ^ 5 ]. > ^ 10 > > > but now I use three if then and I think it's ugly code. > > Is there a way I can make it more the smalltalk way ? > > > Regards, > > Roelof >
Re: [Pharo-users] can I write this without the three if then;s
--- Begin Message --- Hello Richard, Thanks for the feedback. I was using it because the challenge was talking about it, that yu have the use the formula a ^2 + b ^2 = c ^2 and the challenge was talking about the distance and not the distance squared. I think a better name schould be then x or xCoordinate and y or Y_Coordinate. Roelof Op 27-12-2019 om 22:48 schreef Richard O'Keefe: Myself, I see only one issue in your code, and that is the pointless use of sqrt. scoreX: anInteger y: anInteger2 | radiusSquared | radiusSquared := anInteger squared + anInteger2 squared. radiusSquared > 100 ifTrue: [ ^ 0 ]. radiusSquared > 25 ifTrue: [ ^ 1 ]. radiusSquared > 1 ifTrue: [ ^ 5 ]. ^ 10 Make that two issues. The names anInteger and anInteger2. How about scoreHorizontal: horizontal vertical: vertical ... The OO dogma about "if' that you refer to is about not using "if" to make decisions based on TYPE. Making decisions based on NUMERIC RANGES is perfectly OK. You could introduce a 'HalfOpenRangeDictionary" class [K1,K2) -> V1 [K2,K3) -> V2 ... [Kn,infinity) -> Vn But "You Ain't Gonna Need It", so don't. On Sat, 28 Dec 2019 at 08:18, Roelof Wobben via Pharo-users wrote: Hello, Im trying to solve a challenge from exercism where I have to calculate the points somehow gets on a very simple darts board. I solved it like this : scoreX: anInteger y: anInteger2 | distance | distance := (anInteger squared + anInteger2 squared) sqrt. distance > 10 ifTrue: [ ^ 0 ]. distance > 5 ifTrue: [ ^ 1 ]. distance > 1 ifTrue: [ ^ 5 ]. ^ 10 but now I use three if then and I think it's ugly code. Is there a way I can make it more the smalltalk way ? Regards, Roelof --- End Message ---
Re: [Pharo-users] uses or instead of a searching literal
You know, this is an area where style opinions differ a lot. What the message is suggesting you try is aString splitOn: [:each | ' -_' includes: each] That's all. No need for anything more complicated. But there is a trade-off. Clarity vs efficiency. You should make your code clear and correct before you worry about efficiency, true. But you should not go out of your way to make it *less* efficient. The test you have is perfectly readable and is as fast as it gets. Using #includes: would make the code shorter, but not clearer, and certainly slower. You could also use aString splitOn: '[-_ ]' asRegex because #splitOn: is documented as treating strings as regular expressions. This is the briefest, the most confusing to read, and the slowest. It is also by far the most error-prone: - forget "asRegex" and you are in trouble - forget the square brackets and you are in trouble - put the hyphen-minus second instead of first and ... If only #split:indicesDo: were defined for Set. I cannot imagine why it is not. Here is a method definition that goes in the (new) 'splitting' category of Set: split: aSequenceableCollection indicesDo: aBlock "Perform an action specified as aBlock (with a start and end argument) to each of the indices of aSequenceableCollection that have been identified by taking the receiver as a splitter." | position | position := 1. aSequenceableCollection withIndexDo: [:element :idx | (self includes: element) ifTrue: [ aBlock value: position value: idx - 1. position := idx + 1 ]]. aBlock value: position value: aSequenceableCollection size With that in place you can use aString splitOn: ' -_' asSet On Sat, 28 Dec 2019 at 10:24, Roelof Wobben via Pharo-users wrote: > > Hello, > > > How can I get rid of the above error message with this code : > > > abbreviatePhrase: aString > | splitted | > splitted := aString > splitOn: [ :char | char = Character space or: [ char = $- or: [ char > = $_ ] ] ]. > ^ String > streamContents: [ :stream | > splitted > reject: [ :word | word isEmpty ] > thenDo: [ :word | stream nextPut: word first uppercase ] ] > > > Regards, > > Roelof > 'From Pharo7.0.2 of 15 March 2019 [Build information: Pharo-7.0.2+build.154.sha.9f17218676db0c1a0dd5d1b03226e660dbd674b6 (32 Bit)] on 28 December 2019 at 11:33:01.066244 am'! !Set methodsFor: 'splitting' stamp: 'RichardOKeefe 12/28/2019 11:29'! split: aSequenceableCollection indicesDo: aBlock "Perform an action specified as aBlock (with a start and end argument) to each of the indices of aSequenceableCollection that have been identified by taking the receiver as a splitter." | position | position := 1. aSequenceableCollection withIndexDo: [:element :idx | (self includes: element) ifTrue: [ aBlock value: position value: idx - 1. position := idx + 1 ]]. aBlock value: position value: aSequenceableCollection size! ! !Set reorganize! (#'*OpalCompiler-Core' parseOptions:) (#'*Monticello-Storing' comeFullyUpOnReload:) (#copying postCopy) (#adding add:) (#accessing like:ifAbsent: like:) (#converting asSet) (#private rehash fixCollisionsFrom: noCheckAdd: scanFor: grow withArray: noCheckNoGrowFillFrom:) (#'*Random-Core' atRandom:) (#enumerating difference: collect: intersection: do:) (#'*Reflectivity' metaLinkOptions) (#'*ston-core' stonPostReferenceResolution) (#comparing =) (#testing isHealthy occurrencesOf: includes:) (#removing remove:ifAbsent: copyWithout:) (#'*GT-InspectorExtensions-Core' gtInspectorItemsIn:) (#splitting split:indicesDo:) (#'*Fuel-Core' fuelAfterMaterialization fuelAccept: addIfNotPresent:ifPresentDo:) !
[Pharo-users] Hi Community
Hi everyone, my name's Pablo and I'm from Argentina. I'm taking my first steps in Pharo and created this tool (https://github.com/pablo1n7/Smallbook) to share with my colleagues and show them the power of Pharo. It's a simple library to create slide presentations and show them in a web browser. I used Zinc HTTP for the server, JS for the presentation controls and CSS for the styles. It's not 100% complete, I'm still working on it. I hope you find it useful and any suggestion is welcomed Best Regards, Pablo.
Re: [Pharo-users] Hi Community
Looks cool. Thanks for sharing. cheers -ben On Sat, 28 Dec 2019 at 09:55, Pablo Navarro wrote: > Hi everyone, my name's Pablo and I'm from Argentina. I'm taking my first > steps in Pharo and created this tool ( > https://github.com/pablo1n7/Smallbook) to share with my colleagues and > show them the power of Pharo. > > > It's a simple library to create slide presentations and show them in a web > browser. > > > I used Zinc HTTP for the server, JS for the presentation controls and CSS > for the styles. > > > It's not 100% complete, I'm still working on it. I hope you find it useful > and any suggestion is welcomed > > > > Best Regards, Pablo. >
Re: [Pharo-users] uses or instead of a searching literal
--- Begin Message --- Op 27-12-2019 om 23:33 schreef Richard O'Keefe: aString splitOn: ' -_' asSet Hello Richard, Thanks again , I find this "aString splitOn: '_- ` asSet " much cleaner but on some way I does not split for example 'Portable Network Graphics' into " #(Portable, Network, Graphics) ". When I debug it , it seems there is no splitting at all. So today time to dive into it why it does not work and how to solve it. Roelof --- End Message ---
