code review 7423051: doc/effective_go.html: update slices and maps.

doc/effective_go.html: update slices and maps.
Drop the phrase "reference types", which has caused confusion.
Add a section about 2D arrays, a common newbie question.

[r, 2013-03-04 23:52:29]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[cespare, 2013-03-05 02:45:02]

https://codereview.appspot.com/7423051/diff/1/doc/effective_go.html
File doc/effective_go.html (right):

https://codereview.appspot.com/7423051/diff/1/doc/effective_go.html#newcode1432
doc/effective_go.html:1432: If the slices might grown or shrink, they should be
allocated independently
s/grown/grow

[adg, 2013-03-05 03:25:56]

https://codereview.appspot.com/7423051/diff/1/doc/effective_go.html
File doc/effective_go.html (right):

https://codereview.appspot.com/7423051/diff/1/doc/effective_go.html#newcode1456
doc/effective_go.html:1456: array := make([]uint8, XSize*YSize) // Has type
[]uint8 even though picture is [][]uint8.
consider using a name other than "array", to avoid confusion, since the variable
array is a slice.

[r, 2013-03-05 07:23:52]

Hello golang-dev@googlegroups.com, cespare@gmail.com, adg@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[rsc, 2013-03-05 22:09:52]

LGTM

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html
File doc/effective_go.html (right):

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html#newcod...
doc/effective_go.html:1258: of the value explicitly.
what is "the value" here? You can't take the address of the result of make. Did
you mean "a variable"?

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html#newcod...
doc/effective_go.html:1406: type Transform [3][3]float64  // A 2x2 array, really
an array of arrays.
Comment should say 3x3

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html#newcod...
doc/effective_go.html:1459: picture[i] = pixels[i*XSize:(i+1)*XSize]
fine. another common idiom is to avoid the math:

picture[i], pixels = pixels[:XSize], pixels[XSize:]

[r, 2013-03-05 22:13:59]

*** Submitted as https://code.google.com/p/go/source/detail?r=db54b7c5b3e4 ***

doc/effective_go.html: update slices and maps.
Drop the phrase "reference types", which has caused confusion.
Add a section about 2D arrays, a common newbie question.

R=golang-dev, cespare, adg, rsc
CC=golang-dev
https://codereview.appspot.com/7423051

[jondb, 2016-10-16 18:26:26]

Question inline on this change - need more info.

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html
File doc/effective_go.html (right):

https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html#newcod...
doc/effective_go.html:1459: picture[i] = pixels[i*XSize:(i+1)*XSize]
On 2013/03/05 22:09:52, rsc wrote:
> fine. another common idiom is to avoid the math:
> 
> picture[i], pixels = pixels[:XSize], pixels[XSize:]

@rcs - how does this "common idiom" work? It obfuscates what is happening
probably because I'm a new go programmer - however, isn't that what these docs
are for? Looking for ref to docs.

[jondb, 2016-10-16 18:35:40]

On 2016/10/16 18:26:26, jondb wrote:
> Question inline on this change - need more info.
> 
> https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html
> File doc/effective_go.html (right):
> 
>
https://codereview.appspot.com/7423051/diff/6001/doc/effective_go.html#newcod...
> doc/effective_go.html:1459: picture[i] = pixels[i*XSize:(i+1)*XSize]
> On 2013/03/05 22:09:52, rsc wrote:
> > fine. another common idiom is to avoid the math:
> > 
> > picture[i], pixels = pixels[:XSize], pixels[XSize:]
> 
> @rcs - how does this "common idiom" work? It obfuscates what is happening
> probably because I'm a new go programmer - however, isn't that what these docs
> are for? Looking for ref to docs.

Never mind. It's a tuple assignment. I didn't see that - thought some magic was
happening.

http://stackoverflow.com/questions/40073773/how-does-this-common-idiom-actual...