* Re: String to Integer conversion? [not found] ` <6ndi5d$uj3@gcsin3.geccs.gecm.com> @ 1998-07-31 0:00 ` Matthew Heaney 1998-07-30 0:00 ` nabbasi 1998-08-01 0:00 ` Robert Dewar 0 siblings, 2 replies; 11+ messages in thread From: Matthew Heaney @ 1998-07-31 0:00 UTC (permalink / raw) John McCabe <john@assen.demon.co.uk> writes: > Integer_IO provides versions of the Get and Put routines where the first > parameter is a string, so you need to instantiate Integer_IO for your > Integer Type ( or use Ada.Integer_Text_IO for the pre-defined type > Integer) then call the Get operation e.g. In Ada 95 you don't need to instantiate Integer_IO on type Integer. An instantiation of Integer_IO, called Ada.Integer_Text_IO, comes predefined as part of the standard library. Ditto for type Float; there's a predefined instantiation called Float_Text_IO. Q for language lawyers: why no predefined instantiation of Fixed_IO for type Duration? As an alternative solution to the problem of converting a string to an integer, you can use the attribute Integer'Value. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-07-31 0:00 ` String to Integer conversion? Matthew Heaney @ 1998-07-30 0:00 ` nabbasi 1998-08-01 0:00 ` Robert Dewar 1 sibling, 0 replies; 11+ messages in thread From: nabbasi @ 1998-07-30 0:00 UTC (permalink / raw) In article <m37m0vvubh.fsf@mheaney.ni.net>, Matthew says... >As an alternative solution to the problem of converting a string to an >integer, you can use the attribute Integer'Value. > I love those Ada attributes. very usefull and easy to use. whoever came up with those attribute needs a reward of some sort. Nasser ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-07-31 0:00 ` String to Integer conversion? Matthew Heaney 1998-07-30 0:00 ` nabbasi @ 1998-08-01 0:00 ` Robert Dewar 1998-08-01 0:00 ` Matthew Heaney 1 sibling, 1 reply; 11+ messages in thread From: Robert Dewar @ 1998-08-01 0:00 UTC (permalink / raw) <<Q for language lawyers: why no predefined instantiation of Fixed_IO for type Duration? >> Because these predefined instantiations are intended for simple student use, and one assumes that it is unlikely that students will be mucking with duration values! ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-01 0:00 ` Robert Dewar @ 1998-08-01 0:00 ` Matthew Heaney 1998-08-02 0:00 ` Robert Dewar 0 siblings, 1 reply; 11+ messages in thread From: Matthew Heaney @ 1998-08-01 0:00 UTC (permalink / raw) dewar@merv.cs.nyu.edu (Robert Dewar) writes: > <<Q for language lawyers: why no predefined instantiation of Fixed_IO for > type Duration? > >> > > Because these predefined instantiations are intended for simple student > use, and one assumes that it is unlikely that students will be mucking > with duration values! Fair enough, but it would have been helpful to have a predefined instantiation, so that everyone (ie working programmers like me) can share the same one. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-01 0:00 ` Matthew Heaney @ 1998-08-02 0:00 ` Robert Dewar 1998-08-02 0:00 ` Matthew Heaney 0 siblings, 1 reply; 11+ messages in thread From: Robert Dewar @ 1998-08-02 0:00 UTC (permalink / raw) <<Fair enough, but it would have been helpful to have a predefined instantiation, so that everyone (ie working programmers like me) can share the same one. >> Why? ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-02 0:00 ` Robert Dewar @ 1998-08-02 0:00 ` Matthew Heaney 1998-08-04 0:00 ` Robert Dewar 0 siblings, 1 reply; 11+ messages in thread From: Matthew Heaney @ 1998-08-02 0:00 UTC (permalink / raw) dewar@merv.cs.nyu.edu (Robert Dewar) writes: > <<Fair enough, but it would have been helpful to have a predefined > instantiation, so that everyone (ie working programmers like me) can > share the same one. > >> > > Why? Perhaps this is just an Ada 83 problem, because that version of Ada didn't have the attributes Duration'Image and Duration'Value. Without those attributes, there is a real need for a Duration_IO. It may indeed be the case the neophyte programmers in a class-room setting don't require the use of Duration. But they can't avoid using a delay statement forever. In my experience, the need for manipulation of Duration strings is _very_ common. One thing I do quite often is to translate an environment variable that represents the value of an entry call delay, for example, or a timeout for I/O to an external device. This way I can tune delays and timeouts without recompiling anything. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-02 0:00 ` Matthew Heaney @ 1998-08-04 0:00 ` Robert Dewar 1998-08-04 0:00 ` Matthew Heaney 0 siblings, 1 reply; 11+ messages in thread From: Robert Dewar @ 1998-08-04 0:00 UTC (permalink / raw) Matthew says <<In my experience, the need for manipulation of Duration strings is _very_ common. One thing I do quite often is to translate an environment variable that represents the value of an entry call delay, for example, or a timeout for I/O to an external device. This way I can tune delays and timeouts without recompiling anything. >> Sure, no one contests that it is often useful to do I/O on Duration values, but that observation is not enough to justify putting a predefined package for this purpose. It is also useful to sort integers, or do a binary search, or or or or or ..... but we do not expect there to be predefined packages for all possible useful things in advance ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-04 0:00 ` Robert Dewar @ 1998-08-04 0:00 ` Matthew Heaney 1998-08-04 0:00 ` David C. Hoos, Sr. 0 siblings, 1 reply; 11+ messages in thread From: Matthew Heaney @ 1998-08-04 0:00 UTC (permalink / raw) dewar@merv.cs.nyu.edu (Robert Dewar) writes: > Sure, no one contests that it is often useful to do I/O on Duration values, > but that observation is not enough to justify putting a predefined package > for this purpose. It is also useful to sort integers, or do a binary > search, or or or or or ..... but we do not expect there to be predefined > packages for all possible useful things in advance Agreed, but here's another argument. My _expectation_ was that there would be a predefined instantiation for type Duration, because other types in Standard had predefined instantations. If it's natural for me to expect something to be there, then maybe it should be there. Maybe. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-08-04 0:00 ` Matthew Heaney @ 1998-08-04 0:00 ` David C. Hoos, Sr. 0 siblings, 0 replies; 11+ messages in thread From: David C. Hoos, Sr. @ 1998-08-04 0:00 UTC (permalink / raw) Matthew Heaney wrote in message ... >Agreed, but here's another argument. My _expectation_ was that there >would be a predefined instantiation for type Duration, because other >types in Standard had predefined instantations. If it's natural for me >to expect something to be there, then maybe it should be there. Maybe. Just to put my two cents' worth in on this subject, let me relate an experience of several years back on a large Ada83 project. I was looking at ways to speed up compilation, reduce executable size, etc., and one of the discoveries I made was that there were dozens of instantiations of Duration_IO throughout the system. The impact of these many instantiations is, to be sure, dependent in large degree on how the implementation does generics. But in this case, there was NOT ONE instance which was necessary -- i.e., all of what was being done could have (should have, in my opinion), and now is being done with the attributes 'image and 'value. In other words, no one was reading or writing to or from files with these instances, so the code for all of the file operations was wasted. I, for one, was glad to see 'image and 'value provided for floating point types, since many of the uses of instances of Float_IO were similarly used for things which could be more simply done with the attributes. David C. Hoos, Sr. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? [not found] <c1.2b8.2Lzh62$03A@zesi.ruhr.de> [not found] ` <6ndi5d$uj3@gcsin3.geccs.gecm.com> @ 1998-07-31 0:00 ` Matthew Heaney 1998-07-31 0:00 ` daniel gaudry 1 sibling, 1 reply; 11+ messages in thread From: Matthew Heaney @ 1998-07-31 0:00 UTC (permalink / raw) haug@localhost.ruhr.de (Haug Buerger) writes: > i can't believe it, but i found no function in the Standard > libs to convert a string, "123", to Integer(123). I found some > GNAT internal functions that do it, but isn't there a standard > way to do it? Use the attribute Integer'Value. declare I : constant Integer := Integer'Value ("123"); begin QED ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: String to Integer conversion? 1998-07-31 0:00 ` Matthew Heaney @ 1998-07-31 0:00 ` daniel gaudry 0 siblings, 0 replies; 11+ messages in thread From: daniel gaudry @ 1998-07-31 0:00 UTC (permalink / raw) Yes there is one of the get statement can use a string as in parameter get(string=> your_string,=>item => your item,=> ..); the same thing does exist for float, enumerations .... ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~1998-08-04 0:00 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <c1.2b8.2Lzh62$03A@zesi.ruhr.de> [not found] ` <6ndi5d$uj3@gcsin3.geccs.gecm.com> 1998-07-31 0:00 ` String to Integer conversion? Matthew Heaney 1998-07-30 0:00 ` nabbasi 1998-08-01 0:00 ` Robert Dewar 1998-08-01 0:00 ` Matthew Heaney 1998-08-02 0:00 ` Robert Dewar 1998-08-02 0:00 ` Matthew Heaney 1998-08-04 0:00 ` Robert Dewar 1998-08-04 0:00 ` Matthew Heaney 1998-08-04 0:00 ` David C. Hoos, Sr. 1998-07-31 0:00 ` Matthew Heaney 1998-07-31 0:00 ` daniel gaudry
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