54 lines
1.7 KiB
Scheme
54 lines
1.7 KiB
Scheme
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;;; The Geesh Shell Interpreter
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;;; Copyright 2018 Timothy Sample <samplet@ngyro.com>
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;;;
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;;; This file is part of Geesh.
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;;;
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;;; Geesh 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 3 of the License, or
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;;; (at your option) any later version.
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;;;
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;;; Geesh 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 Geesh. If not, see <http://www.gnu.org/licenses/>.
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(define-module (geesh environment)
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#:use-module (ice-9 match)
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#:use-module (srfi srfi-9)
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#:export (<environment>
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make-environment
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environment?
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var-ref
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set-var!))
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;;; Commentary:
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;;;
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;;; This module contains data structures and functions for the
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;;; environment of the Shell language.
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;;;
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;;; Code:
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(define-record-type <environment>
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(%make-environment vars)
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environment?
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(vars environment-vars set-environment-vars!))
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(define (make-environment vars)
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;; In order to insure that each pair in the 'vars' alist is mutable,
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;; we copy each one into a new list.
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(%make-environment (map (match-lambda
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((key . val) (cons key val)))
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vars)))
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(define (var-ref env name)
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(assoc-ref (environment-vars env) name))
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(define (set-var! env name val)
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(set-environment-vars! env (acons name val
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(environment-vars env))))
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