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Article contents:== Outdated egg! This is an egg for CHICKEN 4, the unsupported old release. You're almost certainly looking for [[/eggref/5/define-structure|the CHICKEN 5 version of this egg]], if it exists. If it does not exist, there may be equivalent functionality provided by another egg; have a look at the [[https://wiki.call-cc.org/chicken-projects/egg-index-5.html|egg index]]. Otherwise, please consider porting this egg to the current version of CHICKEN. [[tags: egg lang-exts]] [[toc:]] This page is maintained in the package's [[https://github.com/abarbu/define-structure|github repository]]. = define-structure This is a Chicken Scheme egg which implements a QobiScheme-compatible ''define-structure'' macro. The resulting object is implemented as a chicken record. It automatically sets up reader syntax for reading and writing the object. It also integrates with the nondeterminism egg, see ''local-set-{name}-{field}!''. ==== Creation <macro>(define-structure name . fields)</macro> <macro>(define-public-structure name . fields)</macro> <macro>(define-private-structure name . fields)</macro> Creates a new structure. By default all structures are public, generate an export form, making define-structure an alias for define-public-structure. ==== Use The following functions are generated when creating a structure. <procedure>(make-{name} {field0-value} {field1-value} ...)</procedure> <procedure>(make-keywords-{name} {field-name}: {field-value} ...)</procedure> Any fields not defined in ''make-keywords-{name}'' will be uninitialized. <procedure>({name}? obj)</procedure> Tests if ''obj'' is of a ''{name}'' record. <procedure>({name}-{field} obj)</procedure> Accesses the field. <procedure>({name}-{field}-set! obj val)</procedure> <procedure>(set-{name}-{field}! obj val)</procedure> The former is created by chicken's ''define-record'', the latter is added for compatbility with QobiScheme. <procedure>({name}-{field}-setp! obj proc)</procedure> <procedure>(setp-{name}-{field}! obj proc)</procedure> Like ''set-'' but calls ''proc'' witht he current value and updates it to what ''proc'' returns. <procedure>(local-set-{name}-{field}! obj val)</procedure> <procedure>(local-setp-{name}-{field}! obj proc)</procedure> This set! will be undone when backtracking with the nondeterminism egg. <procedure>({name}-{field}-update obj val)</procedure> <procedure>(update-{name}-{field} obj val)</procedure> <procedure>({name}-{field}-updatep obj proc)</procedure> <procedure>(updatep-{name}-{field} obj proc)</procedure> like the ''set'' and ''setp'' versions but these return a new copy of the object. <procedure>(set-{name}! obj {field-key}: {field-value} ...)</procedure> <procedure>(setp-{name}! obj {field-key}: {field-value} ...)</procedure> <procedure>(update-{name} obj {field-key}: {field-value} ...)</procedure> <procedure>(updatep-{name} obj {field-key}: {field-value} ...)</procedure> As above but with keywords. <procedure>(alist->{name} alist)</procedure> <procedure>({name}->alist obj)</procedure> Convert to and back from an alist. <procedure>(old-vector->{name} vector)</procedure> Reads in a vector of the form ''#({case-insensitive-name} {field0} ...)''. This is only provided for compatibility with ''Scheme->C''. Not yet implemented. === License Copyright (c) 2013, Andrei Barbu, Purdue University All rights reserved. Contact Andrei Barbu at andrei@0xab.com. This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program. If not, see http://www.gnu.org/licenses. Description of your changes:

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