51 lines
1.6 KiB
Scheme
51 lines
1.6 KiB
Scheme
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;;; Copyright (c) 1994 by Olin Shivers.
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;;; Handy for defining random flags and constants.
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;;; (define-enum-constant "errno" intr 9) => (define errno/intr 9)
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;;; This is deeply bogus code. It merely serves to demonstrate what a loser
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;;; I am when it comes to serious modern-tech macrology.
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;;; The question: is / the best separator? Alternates: $ . |
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;;; (define-enum-constant fruit apple 1) =>
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;;; (define fruit/apple 1)
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(define-syntax define-enum-constant
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(lambda (form rename compare)
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(let* ((%define (rename 'define))
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(base (let ((b (cadr form)))
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(cond ((string? b) b)
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((symbol? b) (symbol->string b))
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(else (error "Enum constant base must be symbol or string"
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b )))))
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(var (string->symbol (string-append base "/"
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(symbol->string (caddr form)))))
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(value (cadddr form)))
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`(,%define ,var ,value))))
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;;; (define-enum-constants fruit (apple 1) (orange 2))
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;;; => (begin (define-enum-constant fruit apple 1)
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;;; (define-enum-constant fruit orange 2))
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(define-syntax define-enum-constants
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(syntax-rules ()
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((define-enum-constants set (elt val) ...)
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(begin (define-enum-constant set elt val) ...))))
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(define-syntax define-enum-constants-from-x
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(syntax-rules
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()
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((define-enum-constants-from-zero x set ())
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(begin))
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((define-enum-constants-from-zero x set (elt1 elt2 ...))
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(begin (define-enum-constant set elt1 x)
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(define-enum-constants-from-x (+ x 1) set (elt2 ...))))))
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(define-syntax define-enum-constants-from-zero
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(syntax-rules
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()
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((define-enum-constants-from-zero set (elt ...))
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(define-enum-constants-from-x 0 set (elt ...)))))
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