How do you call startsWith with only a predicate
---
import std.algorithm;
import std.ascii;

bool iden(string str)
{
    return str.startsWith!(a => a.isAlpha || a == '_');
}
---

On Sunday, 18 October 2015 at 17:48:20 UTC, Freddy wrote:
> How do you call startsWith with only a predicate
> ---
> import std.algorithm;
> import std.ascii;
>
> bool iden(string str)
> {
>     return str.startsWith!(a => a.isAlpha || a == '_');
> }
> ---

Is this a simplified use case of some actual code you have? Otherwise, you can just do:


bool iden(string str)
{
    auto f = str.front;
    return f.isAlpha || f == '_';
}

On Sunday, 18 October 2015 at 17:58:30 UTC, Meta wrote:
> Is this a simplified use case of some actual code you have? Otherwise, you can just do:
>
>
> bool iden(string str)
> {
>     auto f = str.front;
>     return f.isAlpha || f == '_';
> }

It's simplified, i wanted to check for empty

On Sunday, October 18, 2015 17:48:18 Freddy via Digitalmars-d-learn wrote:
> How do you call startsWith with only a predicate
> ---
> import std.algorithm;
> import std.ascii;
>
> bool iden(string str)
> {
>      return str.startsWith!(a => a.isAlpha || a == '_');
> }
> ---

startsWith doesn't have an overload that takes only a predicate. The existing overloads all require at least one "needle" to search for in the "haystack." An overload that doesn't require a needle could certainly be added, but there isn't one right now.

- Jonathan M Davis

On Sunday, 18 October 2015 at 21:44:57 UTC, Jonathan M Davis wrote:
> startsWith doesn't have an overload that takes only a predicate. The existing overloads all require at least one "needle" to search for in the "haystack." An overload that doesn't require a needle could certainly be added, but there isn't one right now.
>
> - Jonathan M Davis

https://github.com/D-Programming-Language/phobos/pull/3752

On Monday, 19 October 2015 at 19:20:15 UTC, Nordlöw wrote:
> https://github.com/D-Programming-Language/phobos/pull/3752

Is merged now!