02-Mar-2013 22:09, Namespace пишет:
No-no and no.
Just translate list of keywords/types to a bunch of switch-cases that
will give you near optimal performance. Use CTFE to construct that
string of D code.
In fact I proposed to do just 2 levels of switches: first switch by
length then by first char.
I don't understand.
You don't mean something like:
switch (value) {
case "if": isKeyword = true; break;
...
right?
No.
switch(value.length)
case 2:
switch(value[0])
{
case 'i':
switch(value[1]){
case 'f':
return value.length == 2;
case ...
...
}
...
case 3:
...
}
Even simple if you don't want to go for CTFE code-generation is to
make plain array of array. The length of array is exactly 256 i.e.
Even this should have decent speed:
string[][256] keywords = [
null,
null,
...
//at index 'i'
['int', 'if', 'invariant', 'idouble', 'ifloat' ...]
//array of strings starting with char for each
...
];
bool isKeyword(string value)
{
string[] toSearch = keywords[value[0]];
return toSearch.canFind(value);
}
Ok I will try it. Thank you.
--
Dmitry Olshansky
