record 1.0.1

Record

C#-like records for D

Records are classes and provide boilerplate implementations for properties, equality, hashing and toString. Get only fields can be set at construction, or when duplicate is called.

Equality

Classes, interfaces and pointers are checked by reference (they point to the same thing). Basic types and structs are checked by value.

Hashing

The hashing algorithm is very basic. It is result = (31 * result) + currentField for each field (in same order of declaration).

Printing

Only fields are printed. The format is { fieldName = fieldValue, fieldName2 = fieldValue2, ...}.

Examples

General usage:

import drecord;

alias MyRecord = record!(
    get!(int, "x"), /// x is an int, can only be set during construction
    get_set!(float, "y"), /// y is a float, can be get or set whenever
    property!("getDoubleOfX", (r) => r.x * 2), /// a property that returns the double of x
    property!("getMultipleOfX", (r, m) => r.x * m, int), /// that takes an argument and multiples x by that value
    property!("printY", (r) => writeln(r.y)), /// prints y
    property!("resetY", (r) => r.y = 0) /// resets y to 0f
); 

auto r = new MyRecord(12, 4.5f); /// sets x, y

writeln(r); // { x = 12, y = 4.5f }
writeln(r.toHash); // 376

writeln(r.x); // 12
writeln(r.getDoubleOfX); // 24
writeln(r.getMultipleOfX(4)); // 48
r.printY; // 4.5
r.resetY;
writeln(r.y); // 0
r.y = 13f;
r.printY; // 13

/// Duplicate r, and set x to 17 (we can only do this in ctor, or during duplication)
/// This is equivalent to C#'s "with" syntax for records [0]
auto q = r.duplicate!("x")(17); 
writeln(q); // {x = 17, y = 0}
writeln(q == r); // false
writeln(q is r); // false

auto b = r.duplicate; // duplicate, don't change any fields
writeln(b == r); // true
writeln(b is r); // false

Default initialisation:

import drecord;

alias DefaultRecord = record!(
    // The third parameter is a lambda which provides default initialisation
    get!(int, "x", () => 4), // x is set to 4 by default
    get_set(Object, "o", () => new Object) // o is set to a new Object by default
);

auto r = new DefaultRecord; // run the default initialisers
writeln(r); // {x = 4, o = object.Object}

auto q = DefaultRecord.create!"x"(9); // run default initialisers, then set x to 9
writeln(r); // {x = 9, o = object.Object}