On Wednesday, November 9, 2016 at 11:02:35 PM UTC+8, Marvin Renich wrote: > > * T L <tapi...@gmail.com <javascript:>> [161109 05:18]: > > On Friday, October 21, 2016 at 11:26:46 PM UTC+8, T L wrote: > > > Thanks, gri, this is almost the answer I want. > > > > > > I still have two small questions about the short form. > > > 1. would it be good to allow all identifiers in a short form are old > ones > > > (assume there is only one code block)? > > > 2. would it be good/better to let identifiers in a short form not > shadow > > > outer block identifiers? > > > I know the second one will break compatibility. It is not a feature > > > request. It is just a plain question. > > > > > > > how about adding a ::= operator to satisfy above two rules? > > The first one would definitely not be a good design. The problem with > the short variable declaration is that you cannot tell by looking just > at that one line of code which variables are being redeclared and which > continue to refer to a previously existing variable. > > Implementing the second one would only be good if it were part of fixing > the real problem, that is adding a new syntax that allows a single > combined assignment/declaration which requires each variable on the left > side to be individually identified as either a new (possibly shadowing) > variable or an existing variable that is not to be shadowed. > > This has been discussed before, and does not seem likely to ever happen. > > I go out of my way to avoid := when I can, to the point of writing > > var x int > x, err = foo() > > instead of > > x, err := foo() > > when err has been declared earlier in that block. There is no ambiguity > in the code on top; in the bottom statement, you have to look through > the source to find (or not find, which is more of an issue) both x and > err. > > In the single variable case, where there is no ambiguity, > > var x = foo() > > is only three more characters than > > x := foo() > > and is _much_ easier to distinguish as a declaration rather than > assignment, especially for those of us who have experience in many > languages, where := can mean different things in different languages. > It is simply an issue of cognitive load. > > ...Marvin > > yes, := can be avoided totally. but := really has some benefits.
The contradiction is the short form is 80% good with 20% bad side effects. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
