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93a6e9c4a7
`and-let-star.scm'. Updated module name as well. * and-let-star-compat.scm: New file, installed as `and-let*.scm'. * Makefile.am (ice9_sources): Replaced "and-let*.scm" with "and-let-star.scm". (install-data-local): Install "and-let-star-compat.scm" as "and-let*.scm", ignoring errors. (EXTRA_DIST): Distribute `and-let-star-compat.scm'.
48 lines
1.6 KiB
Scheme
48 lines
1.6 KiB
Scheme
;;;; and-let-star.scm --- and-let* syntactic form (draft SRFI-2) for Guile
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;;;; written by Michael Livshin <mike@olan.com>
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;;;;
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;;;; Copyright (C) 1999 Free Software Foundation, Inc.
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;;;;
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;;;; This program is free software; you can redistribute it and/or modify
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;;;; it under the terms of the GNU General Public License as published by
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;;;; the Free Software Foundation; either version 2, or (at your option)
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;;;; any later version.
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;;;;
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;;;; This program is distributed in the hope that it will be useful,
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;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;;;; GNU General Public License for more details.
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;;;;
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;;;; You should have received a copy of the GNU General Public License
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;;;; along with this software; see the file COPYING. If not, write to
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;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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;;;; Boston, MA 02111-1307 USA
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(define-module (ice-9 and-let-star))
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(defmacro and-let* (vars . body)
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(define (expand vars body)
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(cond
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((null? vars)
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`(begin ,@body))
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((pair? vars)
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(let ((exp (car vars)))
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(cond
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((pair? exp)
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(cond
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((null? (cdr exp))
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`(and ,(car exp) ,(expand (cdr vars) body)))
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(else
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(let ((var (car exp))
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(val (cadr exp)))
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`(let (,exp)
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(and ,var ,(expand (cdr vars) body)))))))
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(else
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`(and ,exp ,(expand (cdr vars) body))))))
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(else
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(error "not a proper list" vars))))
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(expand vars body))
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(export-syntax and-let*)
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