Haxe Code Cookbook
Haxe programming cookbookMacros


Overview of Haxe macros snippets and tutorials.

  • Mar 24, 2016 Macros /

     git expression-macro process

    This example executes a process on the system, compile-time. This allows to run a git command git rev-parse HEAD and use its result as the value.

  • Mar 24, 2016 Macros /

     expression-macro building-fields

    This macro function automatically assigns parameters of method to local variables.

  • Mar 23, 2016 Macros /

     expression-macro validation

    Sometimes failed assertion checks make it difficult to tell what went wrong. For debugging the programmer not only wants to know that a check failed, but also why it failed. This macro outputs the values of all sub-expressions.

  • Jan 03, 2017 Macros /

     build-function building-fields array

    Sometimes it is useful make your arrays compile-time, for example to embed data from files, to pre-calculate heavy calculations, generating lookup tables and other similar things. With macros this is perfectly doable but requires some basic knowledge of expression building. In this article you will find out how to build arrays and return them as expressions in a macro function.

  • Apr 03, 2016 Macros /

     build-macro building-fields

    This snippet demonstrates how to add a map field to a type.

  • Mar 22, 2016 Macros /

     build-macro building-fields

    Virtually adds this property to a class: public var myVar(get, null):Float; private inline function get_myVar():Float { return 1.5; }

  • Mar 22, 2016 Macros /

     build-macro building-fields

    Virtually adds this static variable to a class: public inline static var STATIC_VAR:Float = 1.5;

  • Mar 22, 2016 Macros /

     build-macro building-fields

    This example generates a constructor-function for each field of a class to easily create value object classes.

  • Apr 19, 2016 Macros /


    Haxe makes it easy to define extensions for a typedef, but there is no easy way to combine the values of two or more structures to one, like {a:2} and {b:foo} to {a:2,b:foo}. The following macro does this for you.

  • Mar 26, 2016 Macros /

     completion build-macro

    This example will load an URL, scrape all id's from the HTML page and use them for auto-completion.

  • Mar 25, 2016 Macros /

     enum expression-macro

    The following macro function returns an array of all possible values of a given @:enum abstract type. Since it's not possible in runtime (because abstracts doesn't exist there), we need to use a macro for that.

  • Mar 29, 2016 Macros /

     enum pattern-matching expression-macro

    Sometimes we have an instance of enum that is of known constructor (or we only accept that constructor) and we want to extract values from that instance. Normally, to do this, we have to use pattern matching (switch), however it's quite verbose, so we can instead use this macro static extension method that will generate switch for us.

  • Mar 26, 2016 Macros /

     arguments building-fields build-macro

    Automatically generate dispatch functions as:

  • Jun 16, 2016 Macros /


    This example shows:

  • Apr 25, 2016 Macros /

     conditional-compilation expression-macro

    This snippet demonstrates how to get, set, check for, and list compiler flags.

  • Jul 04, 2017 Macros /

     build-macro building-fields expression-macro

    This example lets you take a file next to the current module .hx file and include its file content. That can be very useful if you want to separate (for example) view templates, shader sources or other multiline texts from the Haxe source. The articles demonstrates how to do it with an expression macro but also with a build macro.

  • Mar 22, 2016 Macros /

     json validation expression-macro

    Json is quite a strict format. Ensure all comma's and quotes are correct using a macro function, which is executed while compiling.