On 05/29/2015 06:43 PM, tcak wrote:
I have define an immutable string array:
[code]
immutable string[] placeHolderDefinitionList = [
"<!-- fullname -->",
"<!-- list item -->"
];
[/code]
I need to get index of a string at compile time. So I have written a
function as below:
[code]
public size_t getPlaceholderIndex(string PlaceHolderText)( size_t
lookIndex = 0 ){
static if( lookIndex >= placeHolderDefinitionList.length )
return size_t.max;
static if( placeHolderDefinitionList[lookIndex] == PlaceHolderText )
return lookIndex;
else
return getPlaceholderIndex( lookIndex + 1 );
}
[/code]
Called it as below:
[code]
writeln( "Index: ", getPlaceholderIndex!"<!-- list item -->"( 0 ) );
[/code]
Compiler didn't like my code. It said those things to my face:
main.d(22): Error: variable lookIndex cannot be read at compile time
main.d(25): Error: variable lookIndex cannot be read at compile time
main.d(28): Error: template main.getPlaceholderIndex cannot deduce
function from argument types !()(ulong), candidates are:
main.d(21): main.getPlaceholderIndex(string
PlaceHolderText)(size_t lookIndex = 0)
main.d(105): Error: template instance main.getPlaceholderIndex!"<!--
list item -->" error instantiating
This is my first try with this type of code. So I am confused a little
about what I should be doing.
The easiest way is to just write runtime code and evaluate it via CTFE:
immutable string[] placeHolderDefinitionList = [
"<!-- fullname -->",
"<!-- list item -->"
];
void main(){
import std.stdio, std.algorithm;
enum index=placeHolderDefinitionList.countUntil("<!-- list item -->");
writeln("Index: ", index);
}
If you never need the placeHolderDefinitionList at runtime, make it enum
instead of immutable.
