digitalmars.D.learn - Semi Automated Object wrapping
- Rory McGuire (116/116) Aug 12 2009 Here is some code I wrote which enables wrapping a proxy around an objec...
- Bill Baxter (22/136) Aug 12 2009 .
- Rory McGuire (2/153) Aug 13 2009 Where would you propose that one would use 'macro'?
- Bill Baxter (32/185) Aug 13 2009 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D // autho...
- Daniel Keep (9/186) Aug 13 2009 I did a blog post about that.
- Rory McGuire (10/201) Aug 13 2009 hm, that does look neater. I might use that.
- bearophile (7/11) Aug 13 2009 Currently you can do (I think it doesn't work well in D2 now):
Here is some code I wrote which enables wrapping a proxy around an object.
I am using it for my serialization library. It works in D1(1.046) and D2
(2.031)
Posting it here for reference by all before I add to much of the stuff
specific to my use, should make it easier to follow.
usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would
implement the methods getInt setInt and getString from A in the new class.
the code below will fail to compile but not before printing the generated
code to stdout.
Shin Fujishiro has made some new templates for D2 which will make it so I
can get rid of the "setInt getInt getString" part which would make the
usage for D2: new ProxyClass!A;
which would be great!
-Rory
============================================
// author: Rory McGuire, rjmcguire gmail.com
import std.stdio;
import std.typetuple;
import std.traits;
import std.metastrings;
//import serializer;
// this CTF from somewhere on news.digitalmars.com
string[] splitFuncs(string str) {
string[] res;
while (str.length > 0) {
while (str.length > 0 && (' ' == str[0] || ',' == str[0])) {
str = str[1..$];
}
int to = 0;
for (; to < str.length && str[to] != ' ' && str[to] != ','; ++to)
{}
if (to > 0) {
res ~= str[0..to];
str = str[to..$];
}
}
return res;
}
string MethodTypeTuple_mixin(alias a)(string[] methods) {
string ret = "TypeTuple!("~ "typeof(&C.init."~methods[0]~")";
foreach (method; methods[1..$]) {
ret ~= ",typeof(&C.init."~method~")";
}
ret ~= ")";
return ret;
}
// test case
class A {
int a;
this(int a) {
this.a = a;
}
int getInt(string intname) {
return a;
}
void setInt(int i) {
a = i;
}
string getString(string s) {
return s ~"1234";
}
}
string ProxyMethods_mixin(alias C, string methodstr)() {
string ret;
foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs
(methodstr)))) {
// output function header
ret ~= "\t"~ReturnType!(t).stringof ~" "~ splitFuncs
(methodstr)[i]~"(";
// output first arg
ret ~= ParameterTypeTuple!(t)[0].stringof~" arg";
// output remainder of args
foreach (j, t1; ParameterTypeTuple!(t)[1..$]) {
ret ~= ","~t1.stringof~"
arg"~std.metastrings.ToString!(j);
}
// output body
ret ~= ") {\n";
// output serialization code
// send method name
ret ~= "\t\twritefln(\"serialize docall id\"); // the
method call byte id\n";
ret ~= "\t\tbuffer ~= serialize!(string)(\""~splitFuncs
(methodstr)[i]~"\", s_state); /+ the method name +/\n";
// send args
ret ~= "\t\tbuffer ~= serialize!("~ ParameterTypeTuple!(t)
[0].stringof~")(arg, s_state); /+ the first argument +/\n";
foreach (j, t1; ParameterTypeTuple!(t)[1..$]) {
ret ~= "\t\tbuffer ~= serialize!("~ t1.stringof
~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n";
}
// receive return type
static if (!is(ReturnType!(t) == void)) {
ret ~= "\t\treturn deserialize!("~ ReturnType!
(t).stringof ~")(buffer, des_state);\n";
}
ret ~= "\t}\n";
}
return ret;
}
class ProxyClass(alias C, string methodstr) {
ubyte[] buffer;
mixin(ProxyMethods_mixin!(C,methodstr)());
pragma(msg, "class ProxyClass!("~C.stringof~", \""~
methodstr ~"\") {\n\tubyte[] buffer;\n SerializerState s_state;\n
DeserializerState des_state;\n this() {s_state = new SerializerState();
des_state = new DeserializerState(); }\n\n"~ ProxyMethods_mixin!
(C,methodstr)() ~"\n}\n");
}
void main() {
auto pc = new ProxyClass!(A, cast(string)"getInt setInt
getString");
writefln("ProxyClass: "~ pc.getString("asdf"));
}
Aug 12 2009
On Wed, Aug 12, 2009 at 4:52 PM, Rory McGuire<rjmcguire gmail.com> wrote:Here is some code I wrote which enables wrapping a proxy around an object=.I am using it for my serialization library. It works in D1(1.046) and D2 (2.031) Posting it here for reference by all before I add to much of the stuff specific to my use, should make it easier to follow. usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would implement the methods getInt setInt and getString from A in the new class=.the code below will fail to compile but not before printing the generated code to stdout. Shin Fujishiro has made some new templates for D2 which will make it so I can get rid of the "setInt getInt getString" part which would make the usage for D2: new ProxyClass!A; which would be great! -Rory =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D==3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D// author: Rory McGuire, rjmcguire gmail.com import std.stdio; import std.typetuple; import std.traits; import std.metastrings; //import serializer; // this CTF from somewhere on news.digitalmars.com string[] splitFuncs(string str) { =A0 =A0string[] res; =A0 =A0while (str.length > 0) { =A0 =A0 =A0 =A0while (str.length > 0 && (' ' =3D=3D str[0] || ',' =3D=3D =str[0])) {=A0 =A0 =A0 =A0 =A0 =A0str =3D str[1..$]; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0int to =3D 0; =A0 =A0 =A0 =A0for (; to < str.length && str[to] !=3D ' ' && str[to] !=3D=','; ++to){} =A0 =A0 =A0 =A0if (to > 0) { =A0 =A0 =A0 =A0 =A0 =A0res ~=3D str[0..to]; =A0 =A0 =A0 =A0 =A0 =A0str =3D str[to..$]; =A0 =A0 =A0 =A0} =A0 =A0} =A0 =A0return res; } string MethodTypeTuple_mixin(alias a)(string[] methods) { =A0 =A0 =A0 =A0string ret =3D "TypeTuple!("~ "typeof(&C.init."~methods[0]=~")";=A0 =A0 =A0 =A0foreach (method; methods[1..$]) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ",typeof(&C.init."~method~")"; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0ret ~=3D ")"; =A0 =A0 =A0 =A0return ret; } // test case class A { =A0 =A0 =A0 =A0int a; =A0 =A0 =A0 =A0this(int a) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0this.a =3D a; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0int getInt(string intname) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return a; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0void setInt(int i) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0a =3D i; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0string getString(string s) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return s ~"1234"; =A0 =A0 =A0 =A0} } string ProxyMethods_mixin(alias C, string methodstr)() { =A0 =A0 =A0 =A0string ret; =A0 =A0 =A0 =A0foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs (methodstr)))) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output function header =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t"~ReturnType!(t).stringof ~" "=~ splitFuncs(methodstr)[i]~"("; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output first arg =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ParameterTypeTuple!(t)[0].stringo=f~" arg";=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output remainder of args =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0foreach (j, t1; ParameterTypeTuple!(t)[1..=$]) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ","~t1.stringof~" arg"~std.metastrings.ToString!(j); =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output body =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ") {\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output serialization code =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// send method name =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\twritefln(\"serialize docall =id\"); // themethod call byte id\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=3D serialize!(strin=g)(\""~splitFuncs(methodstr)[i]~"\", s_state); /+ the method name +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// send args =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=3D serialize!("~ Pa=rameterTypeTuple!(t)[0].stringof~")(arg, s_state); /+ the first argument +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0foreach (j, t1; ParameterTypeTuple!(t)[1..=$]) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=3D =serialize!("~ t1.stringof~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// receive return type =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0static if (!is(ReturnType!(t) =3D=3D void)=) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\treturn deser=ialize!("~ ReturnType!(t).stringof ~")(buffer, des_state);\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t}\n"; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0return ret; } class ProxyClass(alias C, string methodstr) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ubyte[] buffer; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0mixin(ProxyMethods_mixin!(C,methodstr)()); =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0pragma(msg, "class ProxyClass!("~C.stringo=f~", \""~methodstr ~"\") {\n\tubyte[] buffer;\n =A0SerializerState s_state;\n DeserializerState des_state;\n =A0this() {s_state =3D new SerializerState=();des_state =3D new DeserializerState(); }\n\n"~ ProxyMethods_mixin! (C,methodstr)() ~"\n}\n"); } void main() { =A0 =A0 =A0 =A0auto pc =3D new ProxyClass!(A, cast(string)"getInt setInt getString"); =A0 =A0 =A0 =A0writefln("ProxyClass: "~ pc.getString("asdf")); }That code is screaming for some macros. Or variable interpolation at least. --bb
Aug 12 2009
On Wed, 12 Aug 2009 17:03:17 -0700, Bill Baxter wrote:On Wed, Aug 12, 2009 at 4:52 PM, Rory McGuire<rjmcguire gmail.com> wrote:Where would you propose that one would use 'macro'?Here is some code I wrote which enables wrapping a proxy around an object. I am using it for my serialization library. It works in D1(1.046) and D2 (2.031) Posting it here for reference by all before I add to much of the stuff specific to my use, should make it easier to follow. usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would implement the methods getInt setInt and getString from A in the new class. the code below will fail to compile but not before printing the generated code to stdout. Shin Fujishiro has made some new templates for D2 which will make it so I can get rid of the "setInt getInt getString" part which would make the usage for D2: new ProxyClass!A; which would be great! -Rory ============================================ // author: Rory McGuire, rjmcguire gmail.com import std.stdio; import std.typetuple; import std.traits; import std.metastrings; //import serializer; // this CTF from somewhere on news.digitalmars.com string[] splitFuncs(string str) { string[] res; while (str.length > 0) { while (str.length > 0 && (' ' == str[0] || ',' == str[0])) { str = str[1..$]; } int to = 0; for (; to < str.length && str[to] != ' ' && str[to] != ','; ++to) {} if (to > 0) { res ~= str[0..to]; str = str[to..$]; } } return res; } string MethodTypeTuple_mixin(alias a)(string[] methods) { string ret = "TypeTuple!("~ "typeof(&C.init."~methods[0]~")"; foreach (method; methods[1..$]) { ret ~= ",typeof(&C.init."~method~")"; } ret ~= ")"; return ret; } // test case class A { int a; this(int a) { this.a = a; } int getInt(string intname) { return a; } void setInt(int i) { a = i; } string getString(string s) { return s ~"1234"; } } string ProxyMethods_mixin(alias C, string methodstr)() { string ret; foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs (methodstr)))) { // output function header ret ~= "\t"~ReturnType!(t).stringof ~" "~ splitFuncs (methodstr)[i]~"("; // output first arg ret ~= ParameterTypeTuple!(t)[0].stringof~" arg"; // output remainder of args foreach (j, t1; ParameterTypeTuple!(t)[1..$]) { ret ~= ","~t1.stringof~" arg"~std.metastrings.ToString!(j); } // output body ret ~= ") {\n"; // output serialization code // send method name ret ~= "\t\twritefln(\"serialize docall id\"); // the method call byte id\n"; ret ~= "\t\tbuffer ~= serialize!(string)(\""~splitFuncs (methodstr)[i]~"\", s_state); /+ the method name +/\n"; // send args ret ~= "\t\tbuffer ~= serialize!("~ ParameterTypeTuple!(t) [0].stringof~")(arg, s_state); /+ the first argument +/\n"; foreach (j, t1; ParameterTypeTuple!(t)[1..$]) { ret ~= "\t\tbuffer ~= serialize!("~ t1.stringof ~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n"; } // receive return type static if (!is(ReturnType!(t) == void)) { ret ~= "\t\treturn deserialize!("~ ReturnType! (t).stringof ~")(buffer, des_state);\n"; } ret ~= "\t}\n"; } return ret; } class ProxyClass(alias C, string methodstr) { ubyte[] buffer; mixin(ProxyMethods_mixin!(C,methodstr)()); pragma(msg, "class ProxyClass!("~C.stringof~", \""~ methodstr ~"\") {\n\tubyte[] buffer;\n SerializerState s_state;\n DeserializerState des_state;\n this() {s_state = new SerializerState(); des_state = new DeserializerState(); }\n\n"~ ProxyMethods_mixin! (C,methodstr)() ~"\n}\n"); } void main() { auto pc = new ProxyClass!(A, cast(string)"getInt setInt getString"); writefln("ProxyClass: "~ pc.getString("asdf")); }That code is screaming for some macros. Or variable interpolation at least. --bb
Aug 13 2009
On Thu, Aug 13, 2009 at 12:43 AM, Rory McGuire<rjmcguire gmail.com> wrote:On Wed, 12 Aug 2009 17:03:17 -0700, Bill Baxter wrote:=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D // author: = Rory McGuire,On Wed, Aug 12, 2009 at 4:52 PM, Rory McGuire<rjmcguire gmail.com> wrote:Here is some code I wrote which enables wrapping a proxy around an object. I am using it for my serialization library. It works in D1(1.046) and D2 (2.031) Posting it here for reference by all before I add to much of the stuff specific to my use, should make it easier to follow. usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would implement the methods getInt setInt and getString from A in the new class. the code below will fail to compile but not before printing the generated code to stdout. Shin Fujishiro has made some new templates for D2 which will make it so I can get rid of the "setInt getInt getString" part which would make the usage for D2: new ProxyClass!A; which would be great! -Rory =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D==3D str[0])) {rjmcguire gmail.com import std.stdio; import std.typetuple; import std.traits; import std.metastrings; //import serializer; // this CTF from somewhere on news.digitalmars.com string[] splitFuncs(string str) { =A0 =A0string[] res; =A0 =A0while (str.length > 0) { =A0 =A0 =A0 =A0while (str.length > 0 && (' ' =3D=3D str[0] || ',' =3D==3D ',';=A0 =A0 =A0 =A0 =A0 =A0str =3D str[1..$]; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0int to =3D 0; =A0 =A0 =A0 =A0for (; to < str.length && str[to] !=3D ' ' && str[to] !="~=A0 =A0 =A0 =A0++to) {} =A0 =A0 =A0 =A0if (to > 0) { =A0 =A0 =A0 =A0 =A0 =A0res ~=3D str[0..to]; =A0 =A0 =A0 =A0 =A0 =A0str =3D str[to..$]; =A0 =A0 =A0 =A0} =A0 =A0} =A0 =A0return res; } string MethodTypeTuple_mixin(alias a)(string[] methods) { =A0 =A0 =A0 =A0string ret =3D "TypeTuple!("~ =A0 =A0 =A0 =A0"typeof(&C.init."~methods[0]~")"; foreach (method; =A0 =A0 =A0 =A0methods[1..$]) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ",typeof(&C.init."~method~")"; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0ret ~=3D ")"; =A0 =A0 =A0 =A0return ret; } // test case class A { =A0 =A0 =A0 =A0int a; =A0 =A0 =A0 =A0this(int a) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0this.a =3D a; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0int getInt(string intname) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return a; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0void setInt(int i) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0a =3D i; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0string getString(string s) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return s ~"1234"; =A0 =A0 =A0 =A0} } string ProxyMethods_mixin(alias C, string methodstr)() { =A0 =A0 =A0 =A0string ret; =A0 =A0 =A0 =A0foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs (methodstr)))) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output function header =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t"~ReturnType!(t).stringof ~"=gof~"=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0splitFuncs (methodstr)[i]~"("; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output first arg =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ParameterTypeTuple!(t)[0].strin=..$]) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0arg"; // output remainder of args =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0foreach (j, t1; ParameterTypeTuple!(t)[1=~"=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ","~t1.stringof=l id\");arg"~std.metastrings.ToString!(j); =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output body =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D ") {\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// output serialization code =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// send method name =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\twritefln(\"serialize docal=..$]) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// the method call byte id\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=3D =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0serialize!(string)(\""~splitFuncs (methodstr)[i]~"\", s_state); /+ the method name +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// send args =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=3D serialize!("~ =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ParameterTypeTuple!(t) [0].stringof~")(arg, s_state); /+ the first argument +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0foreach (j, t1; ParameterTypeTuple!(t)[1==3D serialize!("~=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\tbuffer ~=d)) {=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0t1.stringof ~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0// receive return type =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0static if (!is(ReturnType!(t) =3D=3D voi=erialize!("~=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t\treturn des=);=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ReturnType! (t).stringof ~")(buffer, des_state);\n"; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret ~=3D "\t}\n"; =A0 =A0 =A0 =A0} =A0 =A0 =A0 =A0return ret; } class ProxyClass(alias C, string methodstr) { =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ubyte[] buffer; =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0mixin(ProxyMethods_mixin!(C,methodstr)()=gof~",=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0pragma(msg, "class ProxyClass!("~C.strin=t=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0\""~ methodstr ~"\") {\n\tubyte[] buffer;\n =A0SerializerState s_state;\n DeserializerState des_state;\n =A0this() {s_state =3D new SerializerState(); des_state =3D new DeserializerState(); }\n\n"~ ProxyMethods_mixin! (C,methodstr)() ~"\n}\n"); } void main() { =A0 =A0 =A0 =A0auto pc =3D new ProxyClass!(A, cast(string)"getInt setIn=It doesn't exist yet, so there's not much you can do about it. Unfortunately code that generates code in D pretty much has to look like what you wrote there. I'm just saying it's not a lot of fun to read such code. Compare with Lisp macros that are almost as readable as regular Lisp functions. Or maybe instead of macros, what's needed is variable interpolation like Perl has. Meaning you can embed a variable inside a string. (e.g. http://www.perlmeme.org/howtos/using_perl/interpolation.html) If one could write something like ret ~=3D "\t$ReturnType!(t).stringof splitFuncs(methodstr)[i](" It would at least look a bit nicer than ret ~=3D "\t"~ReturnType!(t).stringof ~" "~splitFuncs(methodstr)[i]~"(= "; with all the ~" "~ everywhere. --bbWhere would you propose that one would use 'macro'?getString"); =A0 =A0 =A0 =A0writefln("ProxyClass: "~ pc.getString("asdf")); }That code is screaming for some macros. Or variable interpolation at least. --bb
Aug 13 2009
Bill Baxter wrote:On Thu, Aug 13, 2009 at 12:43 AM, Rory McGuire<rjmcguire gmail.com> wrote:I did a blog post about that. http://while-nan.blogspot.com/2007/06/mixins-ctfe-and-shell-style-variable.html For reference, you could (with a few modifications) make it look like this: mixin(ctsub(` ret ~= "\t${ReturnType!(t).stringof} splitFuncs(methodstr)[i](" `)); Not perfect, but perhaps slightly more readable. I don't remember how robust the parsing logic was, though.On Wed, 12 Aug 2009 17:03:17 -0700, Bill Baxter wrote:It doesn't exist yet, so there's not much you can do about it. Unfortunately code that generates code in D pretty much has to look like what you wrote there. I'm just saying it's not a lot of fun to read such code. Compare with Lisp macros that are almost as readable as regular Lisp functions. Or maybe instead of macros, what's needed is variable interpolation like Perl has. Meaning you can embed a variable inside a string. (e.g. http://www.perlmeme.org/howtos/using_perl/interpolation.html) If one could write something like ret ~= "\t$ReturnType!(t).stringof splitFuncs(methodstr)[i](" It would at least look a bit nicer than ret ~= "\t"~ReturnType!(t).stringof ~" "~splitFuncs(methodstr)[i]~"("; with all the ~" "~ everywhere. --bbOn Wed, Aug 12, 2009 at 4:52 PM, Rory McGuire<rjmcguire gmail.com> wrote:Where would you propose that one would use 'macro'?Here is some code I wrote which enables wrapping a proxy around an object. I am using it for my serialization library. It works in D1(1.046) and D2 (2.031) Posting it here for reference by all before I add to much of the stuff specific to my use, should make it easier to follow. usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would implement the methods getInt setInt and getString from A in the new class. the code below will fail to compile but not before printing the generated code to stdout. Shin Fujishiro has made some new templates for D2 which will make it so I can get rid of the "setInt getInt getString" part which would make the usage for D2: new ProxyClass!A; which would be great! -Rory ============================================ // author: Rory McGuire, rjmcguire gmail.com import std.stdio; import std.typetuple; import std.traits; import std.metastrings; //import serializer; // this CTF from somewhere on news.digitalmars.com string[] splitFuncs(string str) { string[] res; while (str.length > 0) { while (str.length > 0 && (' ' == str[0] || ',' == str[0])) { str = str[1..$]; } int to = 0; for (; to < str.length && str[to] != ' ' && str[to] != ','; ++to) {} if (to > 0) { res ~= str[0..to]; str = str[to..$]; } } return res; } string MethodTypeTuple_mixin(alias a)(string[] methods) { string ret = "TypeTuple!("~ "typeof(&C.init."~methods[0]~")"; foreach (method; methods[1..$]) { ret ~= ",typeof(&C.init."~method~")"; } ret ~= ")"; return ret; } // test case class A { int a; this(int a) { this.a = a; } int getInt(string intname) { return a; } void setInt(int i) { a = i; } string getString(string s) { return s ~"1234"; } } string ProxyMethods_mixin(alias C, string methodstr)() { string ret; foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs (methodstr)))) { // output function header ret ~= "\t"~ReturnType!(t).stringof ~" "~ splitFuncs (methodstr)[i]~"("; // output first arg ret ~= ParameterTypeTuple!(t)[0].stringof~" arg"; // output remainder of args foreach (j, t1; ParameterTypeTuple!(t)[1...$]) { ret ~= ","~t1.stringof~" arg"~std.metastrings.ToString!(j); } // output body ret ~= ") {\n"; // output serialization code // send method name ret ~= "\t\twritefln(\"serialize docall id\"); // the method call byte id\n"; ret ~= "\t\tbuffer ~= serialize!(string)(\""~splitFuncs (methodstr)[i]~"\", s_state); /+ the method name +/\n"; // send args ret ~= "\t\tbuffer ~= serialize!("~ ParameterTypeTuple!(t) [0].stringof~")(arg, s_state); /+ the first argument +/\n"; foreach (j, t1; ParameterTypeTuple!(t)[1...$]) { ret ~= "\t\tbuffer ~= serialize!("~ t1.stringof ~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n"; } // receive return type static if (!is(ReturnType!(t) == void)) { ret ~= "\t\treturn deserialize!("~ ReturnType! (t).stringof ~")(buffer, des_state);\n"; } ret ~= "\t}\n"; } return ret; } class ProxyClass(alias C, string methodstr) { ubyte[] buffer; mixin(ProxyMethods_mixin!(C,methodstr)()); pragma(msg, "class ProxyClass!("~C.stringof~", \""~ methodstr ~"\") {\n\tubyte[] buffer;\n SerializerState s_state;\n DeserializerState des_state;\n this() {s_state = new SerializerState(); des_state = new DeserializerState(); }\n\n"~ ProxyMethods_mixin! (C,methodstr)() ~"\n}\n"); } void main() { auto pc = new ProxyClass!(A, cast(string)"getInt setInt getString"); writefln("ProxyClass: "~ pc.getString("asdf")); }That code is screaming for some macros. Or variable interpolation at least. --bb
Aug 13 2009
Rory McGuire <rjmcguire gmail.com> On Fri, 14 Aug 2009 00:16:39 +1000, Daniel Keep wrote:Bill Baxter wrote:variable.htmlOn Thu, Aug 13, 2009 at 12:43 AM, Rory McGuire<rjmcguire gmail.com> wrote:I did a blog post about that. http://while-nan.blogspot.com/2007/06/mixins-ctfe-and-shell-style-On Wed, 12 Aug 2009 17:03:17 -0700, Bill Baxter wrote:It doesn't exist yet, so there's not much you can do about it. Unfortunately code that generates code in D pretty much has to look like what you wrote there. I'm just saying it's not a lot of fun to read such code. Compare with Lisp macros that are almost as readable as regular Lisp functions. Or maybe instead of macros, what's needed is variable interpolation like Perl has. Meaning you can embed a variable inside a string. (e.g. http://www.perlmeme.org/howtos/using_perl/interpolation.html) If one could write something like ret ~= "\t$ReturnType!(t).stringof splitFuncs(methodstr)[i](" It would at least look a bit nicer than ret ~= "\t"~ReturnType!(t).stringof ~" "~splitFuncs(methodstr)[i]~"("; with all the ~" "~ everywhere. --bbOn Wed, Aug 12, 2009 at 4:52 PM, Rory McGuire<rjmcguire gmail.com> wrote:Where would you propose that one would use 'macro'?Here is some code I wrote which enables wrapping a proxy around an object. I am using it for my serialization library. It works in D1(1.046) and D2 (2.031) Posting it here for reference by all before I add to much of the stuff specific to my use, should make it easier to follow. usage: new ProxyClass!(A, cast(string)"getInt setInt getString"); would implement the methods getInt setInt and getString from A in the new class. the code below will fail to compile but not before printing the generated code to stdout. Shin Fujishiro has made some new templates for D2 which will make it so I can get rid of the "setInt getInt getString" part which would make the usage for D2: new ProxyClass!A; which would be great! -Rory ============================================ // author: Rory McGuire, rjmcguire gmail.com import std.stdio; import std.typetuple; import std.traits; import std.metastrings; //import serializer; // this CTF from somewhere on news.digitalmars.com string[] splitFuncs(string str) { string[] res; while (str.length > 0) { while (str.length > 0 && (' ' == str[0] || ',' == str[0])) { str = str[1..$]; } int to = 0; for (; to < str.length && str[to] != ' ' && str[to] != ','; ++to) {} if (to > 0) { res ~= str[0..to]; str = str[to..$]; } } return res; } string MethodTypeTuple_mixin(alias a)(string[] methods) { string ret = "TypeTuple!("~ "typeof(&C.init."~methods[0]~")"; foreach (method; methods[1..$]) { ret ~= ",typeof(&C.init."~method~")"; } ret ~= ")"; return ret; } // test case class A { int a; this(int a) { this.a = a; } int getInt(string intname) { return a; } void setInt(int i) { a = i; } string getString(string s) { return s ~"1234"; } } string ProxyMethods_mixin(alias C, string methodstr)() { string ret; foreach(i, t; mixin(MethodTypeTuple_mixin!(C)(splitFuncs (methodstr)))) { // output function header ret ~= "\t"~ReturnType!(t).stringof ~" "~ splitFuncs (methodstr)[i]~"("; // output first arg ret ~= ParameterTypeTuple!(t)[0].stringof~" arg"; // output remainder of args foreach (j, t1; ParameterTypeTuple!(t)[1...$]) { ret ~= ","~t1.stringof~" arg"~std.metastrings.ToString!(j); } // output body ret ~= ") {\n"; // output serialization code // send method name ret ~= "\t\twritefln(\"serialize docall id\"); // the method call byte id\n"; ret ~= "\t\tbuffer ~= serialize!(string)(\""~splitFuncs (methodstr)[i]~"\", s_state); /+ the method name +/\n"; // send args ret ~= "\t\tbuffer ~= serialize!("~ ParameterTypeTuple!(t) [0].stringof~")(arg, s_state); /+ the first argument +/\n"; foreach (j, t1; ParameterTypeTuple!(t)[1...$]) { ret ~= "\t\tbuffer ~= serialize!("~ t1.stringof ~")(arg"~ToString!(j)~", s_state); /+ argument "~ToString!(j)~" +/\n"; } // receive return type static if (!is(ReturnType!(t) == void)) { ret ~= "\t\treturn deserialize!("~ ReturnType! (t).stringof ~")(buffer, des_state);\n"; } ret ~= "\t}\n"; } return ret; } class ProxyClass(alias C, string methodstr) { ubyte[] buffer; mixin(ProxyMethods_mixin!(C,methodstr)()); pragma(msg, "class ProxyClass!("~C.stringof~", \""~ methodstr ~"\") {\n\tubyte[] buffer;\n SerializerState s_state;\n DeserializerState des_state;\n this() {s_state = new SerializerState(); des_state = new DeserializerState(); }\n\n"~ ProxyMethods_mixin! (C,methodstr)() ~"\n}\n"); } void main() { auto pc = new ProxyClass!(A, cast(string)"getInt setInt getString"); writefln("ProxyClass: "~ pc.getString("asdf")); }That code is screaming for some macros. Or variable interpolation at least. --bbFor reference, you could (with a few modifications) make it look like this: mixin(ctsub(` ret ~= "\t${ReturnType!(t).stringof} splitFuncs(methodstr)[i](" `)); Not perfect, but perhaps slightly more readable. I don't remember how robust the parsing logic was, though.hm, that does look neater. I might use that. main reason I posted though was because I couldn't find anything about how to do this sort of thing in D that was straight forward, the code as I posted it should hopefully be easy for people learning D ctfe programming. ~= is easy to understand, and keeps the code small, only relying on the standard library. Thanks Rory
Aug 13 2009
Bill Baxter:
ret ~= "\t$ReturnType!(t).stringof splitFuncs(methodstr)[i]("
It would at least look a bit nicer than
ret ~= "\t"~ReturnType!(t).stringof ~" "~splitFuncs(methodstr)[i]~"(";
with all the ~" "~ everywhere.
Currently you can do (I think it doesn't work well in D2 now):
import std.metastrings: Format;
...
ret ~= Format!("\t %s %s(", ReturnType!(t).stringof, splitFuncs(methodstr)[i]);
Bye,
bearophile
Aug 13 2009