Re: [racket-users] Macro question

Let's take a look at this error: "format-id: undefined; cannot reference an identifier before its definition phase: 1" Since format-id is undefined, we need to require the corresponding module. The docs say the identifier is from racket/syntax. Now (require racket/syntax) w

Re: [racket-users] Macro question

Nevermind, I got it working (or at least it seems to work): (define-syntax-rule (defpref ident default test?) (begin (define ident (case-lambda [() (pref 'ident)] [(value) (pref 'ident value)])) (pref 'ident default test?))) Best, Erich -- You received this mess

Re: [racket-users] Macro question

Thanks for your your help. Unfortunately, I haven't managed to get my head around the phases and the question of when symbols are quoted or evaluated. I tried Matthew Buttericks change but it yields an error: "format-id: undefined; cannot reference an identifier before its definition phase: 1"

Re: [racket-users] Macro question

> On Jan 12, 2017, at 6:21 AM, Erich Rast wrote: > > #lang racket > (require framework/preferences) > (provide init-preferences const:app-name const:app-version > pref:db-path) > > (define const:app-name "Virtual Assistant") > (define const:app-version 1.0) > > (define default-datapath

[racket-users] Macro question

Hi all, I'm programming in Racket for many years and still haven't used macros or delved into how they work. Kind of embarrassing... anyway, it should be clear what I want to achieve in the code below. I like to wrap a module around framework/preferences, abstracting from the preference implementa