On: The Go Programming Language, or: Why all C-like la...

[zvrba]

Go is NOT C-like. The same semantics could have been achieved by making minimal changes to the existing C syntax. For me, Go seems to be suffering from the NIH syndrome -- they made many syntax and cosmetic changes to C just for the sake of change itself. (Using {} for compound statements is not enough to qualify the language as 'c-like'.)

I have no doubts that Go authors think that their syntax is superior, but they'll have a hard time convincing me that

  switch nr, er := f.Read(buf[:]); true {

is understandable (snippet taken from Go tutorial).

[chrisjsmith → zvrba]

It is perfectly understandable from my perspective, but the caveat is that I'm used to Go's syntax and idioms and they are quite different from the usual. It has taken a while to unlearn the old way to be honest but I prefer it like this now.

[zvrba → chrisjsmith]

Can you explain the " ; true" part?

[chrisjsmith → zvrba]

Straight from the tutorial:

"Since the switch value is just true, we could leave it off—as is also the situation in a for statement, a missing value means true. In fact, such a switch is a form of if-else chain. While we're here, it should be mentioned that in switch statements each case has an implicit break."

The basic outcome is that:

1. The assignment to er, nr is an initialization statement for the switch.

2. The true (default value if not specified) is used to configure the switch as an if-else chain which is required as the assignment above makes the purpose of the switch ambiguous (is the result of the assignment configuring the switch - how do you do that as multiple values are returned?).

You could rewrite it:

    nr, er := f.Read(buf[:]);
    switch true {
      ...
    }

or even:

    nr, er := f.Read(buf[:]);
    switch {
      ...
    }

But the switch initializer scopes it to the switch block cleanly.

[zvrba → chrisjsmith]

"switch true {...}" or "switch {...}"? really? So how would

  switch 3.141592654 { ... }

affect the case-statements inside?

[supersillyus → zvrba]

When you say "switch <value>", it matches the "case" statements based on if the value after "case" is equal to <value>. So, if you say

    const P = 3.141
    switch 3.141 {
       case P: 
          fmt.Println("This prints") 
    }

When no value is specified after "switch", the value of "true" is implied, which is why you can do:

    switch {
       case a && b: ..
       case something():
    }

[chrisjsmith → zvrba]

No idea as I wouldn't do it :) (sorry - cop out that)