Calling readln() after readf (page 2)

On 7/5/22 17:14, Gary Chike wrote: > So, in order to use `parse!int()`, I would need to separate it into two > statements with a variable acting as an intermediary: > ``` > auto input = readln(); > auto age = parse!int(input); Exactly. parse takes the input by reference (necessitating an lvalue) so that the input is consumed for the next step(s) of parsing. Ali

July 05, 2022

Re: Calling readln() after readf

Posted by Steven Schveighoffer
in reply to Gary Chike

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Steven Schveighoffer

Posted in reply to Gary Chike

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On 7/5/22 8:14 PM, Gary Chike wrote:

On Monday, 20 June 2022 at 16:08:33 UTC, Ali Çehreli wrote:

On 6/20/22 07:00, Gary Chike wrote:

Would it be appropriate to forego readf
and read input as a string using readln ,benefiting from
the strip
function, then convert to their appropriate datatype

Makes sense. The following are related as well:

https://dlang.org/library/std/conv/parse.html

https://dlang.org/library/std/format/read/formatted_read.html

It's interesting from my own experimentation and observation, comparing parse!int() vs to!int() For instance, I can formulate a statement such as this using to!int():
auto age = to!int(readln.strip());
but the same syntax using parse!int() would generate an error:
auto age = parse!int(readln.strip());
So, in order to use parse!int(), I would need to separate it into two statements with a variable acting as an intermediary:

auto input = readln();
auto age = parse!int(input);

Yes, you have 2 orthogonal desires:

I want to update the original range or not
I want to treat the entire range as representing my conversion type or just the first part.

Phobos only handles 2 of the 4 possible scenarios. Well, really one scenario (reading the entire range, and wanting to update the original) is not important.

-Steve

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