Re: [go-nuts] nil maps

wow, super impressed! On Thursday, October 19, 2017 at 10:22:26 AM UTC-7, rog wrote: > > Or taking it a bit further: https://play.golang.org/p/g4uF2QjiJQ > > > On 18 October 2017 at 23:38, Alex Dvoretskiy > wrote: > > Looks fun!: https://play.golang.org/p/8mqzb-1H7f > >

Re: [go-nuts] nil maps

Or taking it a bit further: https://play.golang.org/p/g4uF2QjiJQ On 18 October 2017 at 23:38, Alex Dvoretskiy wrote: > Looks fun!: https://play.golang.org/p/8mqzb-1H7f > > On Tuesday, October 17, 2017 at 10:39:46 AM UTC-7, Thomas Bushnell, BSG > wrote: >> >> Here's a

Re: [go-nuts] nil maps

Looks fun!: https://play.golang.org/p/8mqzb-1H7f On Tuesday, October 17, 2017 at 10:39:46 AM UTC-7, Thomas Bushnell, BSG wrote: > > Here's a case that comes up for me: > > type table map[string]map[string]string > > func (t table) add(x, y, z string) { > if t[x] == nil { > t[x] =

Re: [go-nuts] nil maps

Here's a case that comes up for me: type table map[string]map[string]string func (t table) add(x, y, z string) { if t[x] == nil { t[x] = make(map[string]string) } t[x][y] = z } func (t table) get(x, y string) string { return t[x][y] } The fact that t[x] can be indexed even if it

Re: [go-nuts] nil maps

A nil map is like a regular map but it has nothing in it, cannot grow, and takes zero space. -rob On Tue, Oct 17, 2017 at 5:31 PM, Christian Himpel wrote: > The spec defines: "A nil map is equivalent to an empty map except that no > elements may be added."

Re: [go-nuts] nil maps

The spec defines: "A nil map is equivalent to an empty map except that no elements may be added." https://golang.org/ref/spec#Map_types You could return a nil map, if you have no elements to add, and a caller would just need to read. On Tue, Oct 17, 2017 at 7:02 AM Dan Kortschak

Re: [go-nuts] nil maps

If you only need the map conditionally, you need to declare it and then conditionally make it. ``` var m map[string]int if needMap {     m = make(map[string]int) } ``` On Mon, 2017-10-16 at 21:52 -0700, Alex Dvoretskiy wrote: > Hello, Golang Nuts! > > I have an interesting question about maps.

[go-nuts] nil maps

Hello, Golang Nuts! I have an interesting question about maps. What is the possible usage of nil maps, which can be declared like "var m map[string]int"? You can't write to nil map but have an option to create it. Perhaps there is no use at all and this is just language specific feature?