• Jeremy (10/10) Mar 19 2023 Hello, is there any difference at all between the following
• Basile B. (9/19) Mar 19 2023 The colon-form, aka "selective import" has for effect
• Jeremy (2/12) Mar 19 2023 Ah, that makes sense. Thank you!

Jeremy <jtbx disroot.org> writes:

Hello, is there any difference at all between the following 
lines, as an example:

```d
import std.regex;
import std.regex : matchFirst;
```

What technical differences does it make (except for having the 
identifier available), using the colon?
Does it make any speed/optimization changes or am I better off 
just importing the whole module?

Basile B. <b2.temp gmx.com> writes:

On Sunday, 19 March 2023 at 07:20:17 UTC, Jeremy wrote:
 Hello, is there any difference at all between the following 
 lines, as an example:

 ```d
 import std.regex;
 import std.regex : matchFirst;
 ```

 What technical differences does it make (except for having the 
 identifier available), using the colon?
 Does it make any speed/optimization changes or am I better off 
 just importing the whole module?

The colon-form, aka "selective import" has for effect

1. to create a local alias so this can indeed speedup symbol 
lookups in the sense that search will succeed before looking in 
the scope of the imports.
2. to make non-selected symbols, i.e not listed in the colon 
right hand side, in the import not available.

Note that using both makes no sense, but I guess you did that to 
express more clearly what you meant.

Jeremy <jtbx disroot.org> writes:

On Sunday, 19 March 2023 at 08:47:32 UTC, Basile B. wrote:
 On Sunday, 19 March 2023 at 07:20:17 UTC, Jeremy wrote:
 [...]

 The colon-form, aka "selective import" has for effect

 1. to create a local alias so this can indeed speedup symbol 
 lookups in the sense that search will succeed before looking in 
 the scope of the imports.
 2. to make non-selected symbols, i.e not listed in the colon 
 right hand side, in the import not available.

 Note that using both makes no sense, but I guess you did that 
 to express more clearly what you meant.

Ah, that makes sense. Thank you!