DPaste - Paste #2708 - pastebin, online compiler and collaboration tool dedicated to D Programming Language

Code

import std.typecons, std.traits, std.stdio, std.string;

// from std.functional
template memoize(alias fun, uint maxSize = uint.max)
{
    ReturnType!fun memoize(ParameterTypeTuple!fun args)
    {
        static ReturnType!fun[Tuple!(typeof(args))] memo;
        auto t = tuple(args);
        auto p = t in memo;
        if (p) return *p;
        static if (maxSize != uint.max)
        {
            if (memo.length >= maxSize) memo = null;
        }
        auto r = fun(args);
        //writeln("Inserting result ", typeof(r).stringof, "(", r, ") for parameters ", t);
        memo[t] = r;
		writeln("p: ", p, " - memo: ", memo);
        return r;
    }
}

string slowFuncString(string arg) {
    writeln("Running slowFuncString: ", arg);
    return "";
}

alias memoize!slowFuncString fastFuncString;

void main() {
	string buf;
	
	while (stdin.readln(buf)) {
		fastFuncString(strip(buf));
	}
	
	/*

This should only print:

Running slowFuncString: Test1
	p: null memo: [Tuple!(string)("Test1"):""]
	Running slowFuncString: Test2
	p: null memo: [Tuple!(string)("Test1"):"", Tuple!(string)("Test2"):""

*/
	
}

Application output:

Running slowFuncString: Test1
p: null - memo: [Tuple!(string)("Test1"):""]
Running slowFuncString: Test2
p: null - memo: [Tuple!(string)("Test2"):"", Tuple!(string)("Test1"):""]
Running slowFuncString: Test2
p: null - memo: [Tuple!(string)("Test2"):"", Tuple!(string)("Test2"):"", Tuple!(string)("Test1"):""]
Running slowFuncString: Test2
p: null - memo: [Tuple!(string)("Test2"):"", Tuple!(string)("Test2"):"", Tuple!(string)("Test2"):"", Tuple!(string)("Test1"):""]

Application input:

Test1
Test2
Test2
Test2

Paste info

Author: WelshDragon

Views: 113

Private: no

Expires: Never

Uploaded: 03.10.12 21:42

Votes: 0

Compilation

Compiler: DMD 2.060

Pointer size: m64