On Tue, Feb 21, 2017 at 10:34:57PM +0000, Chad Joan via Digitalmars-d-learn
wrote:
> On Tuesday, 21 February 2017 at 22:26:01 UTC, Chad Joan wrote:
> > On Tuesday, 21 February 2017 at 21:58:07 UTC, Stefan Koch wrote:
> > > On Tuesday, 21 February 2017 at 21:53:23 UTC, Chad Joan wrote:
> > > > Hello all,
> > > >
> > > > I'm trying to make this work:
> > > >
> > > > [...]
> > >
> > > You cannot create AA's at ctfe and carry them over to runtime use.
> > > You'd have to use a costum dictionary-type.
> > > I think the vibe.d project has one you could use.
> >
> > I wondered if this might be the case.
> >
> > Well, I won't worry about it then. I'll have to find another way
> > around.
> >
> > Thanks a bunch!
>
> For the sake of the rest of the internet, here is what I'm probably going to
> stick with:
>
> ---
> pure string[string] parseTwoColumnCsv(string inputCsv)
> {
> import std.csv;
> import std.typecons;
>
> string[string] result;
>
> foreach ( record; csvReader!(Tuple!(string,string))(inputCsv) )
> result[record[0]] = record[1];
>
> return result;
> }
>
> immutable string[string] dataLookup;
>
> static this()
> {
> dataLookup = parseTwoColumnCsv(import("some_data.csv"));
> }
>
> void main()
> {
> import std.stdio;
> writefln("dataLookup = %s", dataLookup);
> }
> ---
>
> In this case the AA isn't actually coded into the executable; but at least
> the configuration from some_data.csv will be in the executable as a string.
> The program will construct the AA at startup. It's not as "cool", but it
> should get the job done.
[...]
Parsing strings at program startup is ugly and slow. What about parsing
at compile-time with CTFE into an array literal and transforming that
into an AA at startup, which should be a lot faster?
// Warning: untested code
pure string[2][] parseTwoColumnCsv(string inputCsv)
{
import std.csv;
import std.typecons;
string[2][] result;
foreach (record; csvReader!(Tuple!(string,string))(inputCsv)) {
result ~= [record[0], record[1]];
}
return result;
}
immutable string[string] dataLookup;
static this()
{
enum halfCookedData =
parseTwoColumnCsv(import("some_data.csv"));
foreach (p; halfCookedData) {
dataLookup[p[0]] = p[1];
}
}
T
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