PC Format Collection 5

home *** CD-ROM | disk | FTP | other *** search

/ PC Format Collection 5 / PCFORMAT5.iso / MODPLAY / CDEC.DOC next >

Wrap

Text File | 1990-10-21 | 12.7 KB | 484 lines

C D E CC D E C C Declaration to English Translator Program C Declaration to English Translator Program for the I.B.M PC/AT and Compatibles by John S. Smith c/o 'Rosemont' Hawthorn Rd Beaufort Ebbw Vale Gwent United Kingdom Copyright (C) 1989-90 by John S. Smith Copyright (C) 1989-90 by John S. Smith All Rights Reserved___ ______ ________ This document last revised 21st October 1990 The CDEC diskette containing a copy of this document is distributed under the Shareware scheme and may be freely copied provided that none of the files thereon are modified in any way. Printed copies of the documentation may not be copied without the express written permission of the author CDEC Guide For C Programmers 1 Introduction 1 Introduction CDEC is a program that translates declarations in the C programming language into an English phrase. CDEC is particularly useful for checking the meaning of complex declarations or even not-so complex declarations when one is unsure of the precedence of operators. For example the difference between: char * msg[MAX_NUM]; and char (* msg)[MAX_NUM]; is easily and quickly found with CDEC. Also, when trying to understand code written by others, declarations can be a particularly troublesome and time-consuming area. CDEC is a great help with this sort of task. Another useful area is when one wishes to use a particularly complex declaration as the problem at hand dictates it, yet how can you be sure the declaration is right? Your compiler may compile it ok but does the declaration mean what you want it to mean? Just enter it to CDEC and get a second opinion. Declarations get even more difficult to understand when the "far" and "near" keywords that are used with many compilers are involved. Just what associates with what? Well, even though "far" and "near" are not part of the C programming language, CDEC includes them as they are in such common usage. There is also support for the "const" keyword. CDEC runs on all PC compatible machines and needs no special hardware or displays. CDEC uses a plain scrolling display rather than pop-up menus etc to minimise code size and thus minimises loading time from disc. It is possible to start CDEC, check a declaration and return to DOS before many programs could even load! (Well I think so anyway). A Shareware Program page 2 October, 1990 CDEC Guide For C Programmers 2 Installation and Test 2 Installation and Test CDEC consists of just one executable file CDEC.EXE. Copy this file to any directory in your current path. 3 Starting CDEC 3 Starting CDEC Type: CDEC or CDEC -x In the latter case CDEC attempts to give extra information about certain declaration where possible. In particular declarations involving "const" and the common compiler extensions for segmented addressing "far" and "near" have extra information. 4 Usage 4 Usage CDEC prompts for a declaration. Type in your declaration and press the Enter or return key. CDEC will produce an English translation on screen if possible. If there is an error, the probable reason is displayed followed by a new prompt for you to try again. The functions keys provide access to much useful information. The "?" key aborts the current declaration without leaving the program. The Esc key exits CDEC. If you wish to save the generated output to a file, use the DOS redirection feature and start CDEC like this: CDEC > myfile CDEC will place the translated output in a file called "myfile". This redirected output is detected by CDEC and the output will be surrounded by standard C comment delimiters /* comment */ so that "myfile" can be included in your source code later if you wish. To end this process, press Esc as before. If any declaration is in error then the A Shareware Program page 3 October, 1990 CDEC Guide For C Programmers error message will always appear on the screen and never be sent to file. You may append a comment to any CDEC input line. Such a comment is introduced by two slashes (//) eg char buf[10]; // store name This comment will also be stored in any redirected output file. It is possible to start CDEC with redirected output AND with the extra information option turned on. eg CDEC -x > myfile In this case, any extra information goes only to file (not to screen) but the translated output goes to screen AND file. CDEC will also accept a list of declarations from a file as redirected input: eg CDEC <list Where the file "list" contains a list of C declaration to be translated. It is possible to use redirected input and output together: eg CDEC < list > myfile or CDEC -x < list > myfile 5 Commom omissions and additional information 5 Commom omissions and additional information Failure to end the declaration with a semicolon ";". ALL declaration require this. CDEC can translate declaration than are beyond the power of current compilers to accept! (At least as far as I am aware). Such declarations are not incorrect as such but it is just that such declarations are maybe too expensive and/or difficult (or unnecessary?) in computing terms to be implemented. Maybe such declarations will never be implemented but CDEC translates them now. This has advantages for educational purposes at least. Typical of such declarations are: A Shareware Program page 4 October, 1990 CDEC Guide For C Programmers int alpha()(); int beta()[]; int gamma[](); Input these to CDEC to see what they mean. Pointers to such items ARE allowed. C declarations, particularly structures and unions are usually written on more than one line: eg struct tag { int count; char * chr; } struct_name; However this format is only for stylistic reasons and such a declaration is just as valid if written on a single line, such as struct tag { int count; char * chr; } struct_name; CDEC requires the single line version as translation starts as soon as the Enter or return key is pressed. This does not limit the length of a declaration and a very long declaration may be greater than one screen line -- just keep typing when the cursor gets to the right hand side of the screen but don't press return until the whole declaration is entered. CDEC translates declarations involving functions arrays pointers "primitive" data types aggregates data types such as struct and unions. Also there is extended support for the "far" "near" and "const" keywords. Note that CDEC identifies but does not parse parameter lists for functions and behaves similarly for struct/union member lists. Each item of any of these lists may be input to CDEC as an independent declaration later if further translation is desired. It is felt that identification of these lists is much more useful than a description of them as they can often be very difficult to identify in a declaration. Also the generated phrase would be rather difficult to read which would defeat the purpose of CDEC. CDEC also does this identification task for initialiser lists. Quite difficult-to-understand declarations may be easily understood with CDEC's output. For example a declaration such as: struct basetype (*root (int ival, char *name)) ( char * buf[10]); produces (actual CDEC output obtained using the redirected output feature): A Shareware Program page 5 October, 1990 CDEC Guide For C Programmers /* --- CDEC TRANSLATOR --- input received: struct basetype (*root (int ival, char *name)) ( char * buf[10]); cdec output: "root": function (params: int ival, char *name) returning pointer to function (params: char * buf[10]) returning structure of type basetype */ Be sure to read the note programmed into function key F2 Remember CDEC handles <typedef>'s too. 6 Shareware users 6 Shareware users Please note that pointers and redirected input features are only supported by the registered versions of CDEC. A registered version can be obtained from: John S. Smith c/o 'Rosemont' Hawthorn Rd Beaufort Ebbw Vale Gwent United Kingdom The cost is 19 pounds sterling + 2 pounds p&p within the U.K. and 3 pounds to other countries. For this you will receive the latest version of CDEC and discounts on any upgrades which you will be notified about. Please state which version you have now and I would appreciate knowing how you learned of CDEC. Any constructive comments would also be welcomed. Please state disc size required, 5.25" or 3.5" 7 Disclaimer 7 Disclaimer Although considerable care has gone into the writing and testing of this program, no responsibility is accepted for the results obtained by using this program. Also no guarantee or warrantee either A Shareware Program page 6 October, 1990 CDEC Guide For C Programmers expressed or implied is given either to the user of the program or to any third parties. I reserve the right to change the specification, capabilities and charges for CDEC without notice. In other words I cannot be bound by old advertising. A Shareware Program page 7 October, 1990 ContentsContents 1 Introduction . . . . . . . . . . 2 2 Installation and Test . . . . . . 2 3 Starting CDEC . . . . . . . . . . 3 4 Usage . . . . . . . . . . . . . . 3 5 Commom omissions and additional information . . . . . . . . . . . 4 6 Shareware users . . . . . . . . . 6 7 Disclaimer . . . . . . . . . . . 6 i