1、ANSI INCITS 215-1994 (R2001)(formerly ANSI X3.215-1994 (R2001)for Information Systems Programming Languages ForthAmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by
2、the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus requ
3、ires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, marketi
4、ng, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or authority t
5、o issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard may b
6、e revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing the A
7、merican National StandardsInstitute.CAUTION: The developers of this standard have requested that holders of patents that may be required for theimplementation of the standard disclose such patents to the publisher. However, neither the developers nor the publisherhave undertaken a patent search in o
8、rder to identify which, if any, patents may apply to this standard. As of the date ofpublication of this standard, following calls for the identification of patents that may be required for the implementation ofthe standard, notice of one or more such claims has been received. By publication of this
9、 standard, no position is takenwith respect to the validity of this claim or of any rights in connection therewith. The known patent holder(s) has (have),however, filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory termsand conditions to applica
10、nts desiring to obtain such a license. Details may be obtained from the publisher. No furtherpatent search is conducted by the developer or publisher in respect to any standard it processes. No representation ismade or implied that this is the only license that may be required to avoid infringement
11、in the use of this standard.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1994 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval system or
12、otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaANSI X3.21 5-l 994 American National Standard for Information Systems - Programming Languages - Forth Secretariat Computer and Business Equipment Manufacturers Associatio
13、n Approved March 24, 1994 American National Standards Institute, Inc. ANSI X3.215-1994 Contents Foreword V X3 Membership . vi X3J14 Membership vii 1. Introduction 1 1.1 Purpose 1 1.2 scope . 1 1.2.1 Inclusions . 1 1.2.2 Exclusions 1 1.3 Document organization . .2 1.3.1 wordsets 1.3.2 Annexes ; 1.4 F
14、uture directions . 2 1.4.1 New technology . 2 1.4.2 Obsolescent features . .2 2. Terms, notation, and references .3 2.1 Definitions of terms 3 2.2 Notation . 5 2.2.1 Numeric notation 5 2.2.2 Stack notation 5 2.2.3 Parsed-text notation . 2.2.4 Glossary notation . i 2.3 References . 7 3. Usage require
15、ments 8 3.1 3.2 3.3 3.4 Data types . 8 3.1.1 Data-type relationships 8 3.1.2 Character types . 8 3.1.3 Single-cell types .lO 3.1.4 Cell-pair types . 11 3.1.5 System types . 11 The implementation environment 12 3.2.1 Numbers . 12 3.2.2 Arithmetic . 12 3.2.3 Stacks 13 3.2.4 Operator terminal 14 3.2.5
16、Mass storage 14 3.2.6 Environmental queries . 14 The Forth dictionary 15 3.3.1 Name space . 15 3.3.2 Code space 15 3.3.3 Dataspace . 15 The Forth text interpreter . 17 3.4.1 Parsing . 18 3.4.2 Finding definition names 18 3.4.3 Semantics . 19 3.4.4 Possible actions on an ambiguous condition 3.4.5 Com
17、pilation 4. Documentation requirements . .21 4.1 System documentation . 21 4.1.1 Implementation-defmed options . 21 4.1.2 Ambiguous conditions . 22 4.1.3 Other system documentation . 23 4.2 Program documentation . 23 4.2.1 Environmental dependencies 23 ii ANSI X3.21 51994 4.2.2 Other program documen
18、tation .23 5. Compliance and labeling . 24 5.1 ANS Forth systems . .24 5.1.1 System compliance . . 5.1.2 System labeling .24 5.2 ANS Forth programs .24 5.2.1 Program compliance 24 5.2.2 Program labeling . .24 6. Glossary 25 6.1 Core words 25 6.2 Core extension words 49 7. The optional Block word set
19、 59 8. The optional Double-Number word set . 65 9. The optional Exception word set .70 10. The optional Facility word set . .74 11. The optional File-Access word set . 77 12. The optional Floating-Point word set . .87 13. The optional Locals word set . 102 14. The optional Memory-Allocation word set
20、 107 15. The optional Programming-Tools word set . 110 16. The optional Search-Order word set . 117 17. The optional Suing word set 122 A. Rationale (informative annex) 125 A. 1 Introduction . 125 A.2 Terms and notation . 126 A.3 Usage requirements . 127 A.4 Documentation requirements . 138 A.5 Comp
21、liance and labeling 138 A.6 Glossary . 139 A.7 The optional Block word set . 157 A.8 The optional Double-Number word set 157 A.9 The optional Exception word set 158 A.10 The optional Facility word set . 161 A.11 The optional File-Access word set 164 A. 12 The optional Floating-Point word set . 166 A
22、. 13 The optional Locals word set 169 A.14 The optional Memory-Allocation word set . 172 A. 15 The optional Programming-Tools word set 172 A. 16 The optional Search-Order word set 175 A.17 The optional String word set . 177 B. Bibliography (informative annex). . 179 C . Perspective (informative anne
23、x). : 18 1 C.l Features of Forth 181 C.2 History of Forth . 182 C.3 Hardware implementations of Forth 182 C.4 Standardization efforts 182 C.5 Programming in Forth . 183 C.6 Multiprogrammed systems . 189 C .7 Design and management considerations . 189 C.8 Conclusion 189 . . . Ill _-.- -_ _- -I_ _.- -
24、 -I,-_-. -LA.-_“ ANSI X3.215-1994 D. Compatibility analysis of ANS Forth (informative annex). 190 D.l FIG Forth (circa 1978) . 190 D.2 Forth 79 . 190 D.3 Forth 83 .190 D.4 Recent developments . 191 D.5 ANS Forth approach . 191 D.6 Differences from Forth 83 192 D.6.1 Stack width . 192 D.6.2 Number re
25、presentation . 192 D.6.3 Address units . 193 D.6.4 Address increment for a ceil is no longer two . 193 D.6.5 Address alignment . 194 D.6.6 Division/modulus rounding direction 195 D.6.7 Immediacy .195 D.6.8 Input character set . 197 D.6.9 Shifting with UM/MOD 197 D.6.10 Vocabularies / wordhsts . 198
26、D.6.11 Multiprogramming impact . 198 D.6.12 Words not provided in executable form 199 E. ANS Forth portability guide (informative annex) . 200 E.l E.2 E.3 E.4 E.5 E.6 Introduction . 200 Hardware peculiarities 200 E.2.1 Data/memory abstraction . .200 E.2.2 Definitions 200 E.2.3 Addressing memory .201
27、 E.2.4 Alignment problems .201 Number representation .202 E.3.1 Big endian vs. little endian . 202 E.3.2 ALU organization . 202 Forth system implementation . 203 E.4.1 Definitions . .203 E.4.2 Stacks 203 ROMed application disciplines and conventions . .204 Summary 204 F. Alphabetic list of words (in
28、formative annex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 ANSI X3.21 5-1994 Foreword (This foreword is not a part of American National Standard X3.215-1 994) Forth is a language for direct communication between human beings and machines. U
29、sing natural-language diction and machine-oriented syntax, Forth provides an economical, productive environment for interactive compilation and execution of programs. Forth also provides low-level access to computer-controlled hardware, and the ability to extend the language itself. This extensibili
30、ty allows the language to be quickly expanded and adapted to special needs and different hardware systems. Forth was invented by Mr. Charles Moore to increase programmer productivity without sacrificing machine efficiency. Forth is a layered environment containing the elements of a computer language
31、 as well as those of an operating system and a machine monitor. This extensible, layered environment provides for highly interactive program development and testing. In the interests of transportability of application software written in Forth, standardization efforts began in the mid-1970s by an in
32、ternational group of users and implementors who adopted the name “Forth Standards Team”. This effort resulted in the Forth-77 Standard. As the language continued to evolve, an interim Forth-78 Standard was published by the Forth Standards Team. Following Forth Standards Team meetings in 1979, the Fo
33、rth-79 Standard was published in 1980. Major changes were made by the Forth Standards Team in the Forth-83 Standard, which was published in 1983. The first meeting of the Technical Committee on Forth Programming Systems was convened by the Organizing Committee of the X3J14 Forth Technical Committee
34、on August 3,1987, and has met subsequently on November ll-12,1987, February 10-12, 1988, May 25-28, 1988, August 10-13, 1988, October 26-29, 1988, January 25-28, 1989, May 3-6,1989, July 26-29, 1989, October 25-28, 1989, January 24-27, 1990, May 22-26, 1990, August 21-25, 1990, November 6-10,1990, J
35、anuary 29-February 2, 1991, May 3-4,1991, June 16-19,1991, July 30-August 3, 1991, March 17-21,1992, October 13-17, 1992, January 26-30, 1993, June 28-30, 1993, and June 21, 1994. This project has operated under joint sponsorship of IEEE as IEEE Project P1141. The TC gratefully acknowledges the supp
36、ort of IEEE in this effort and the participation of the IEEE members who contributed to our work as sponsored members and observers. Requests for interpretation, suggestions for improvement or addenda, or defect reports are welcome. They should be sent to the X3 Secretariat, Computer and Business Eq
37、uipment Manufacturers Association, 1250 Eye Street, NW, Suite 200, Washington, DC 20005. ANSI X3.215-1994 X3 Membership This standard was processed and approved for submittal to ANSI by the Accredited Stan- dards Committee on Information Processing Systems, X3. Committee approval of this standard do
38、es not necessarily imply that all committee members voted for its approval. At the time it approved this standard, the X3 Committee had the following members: James D. Converse, Chair Donald C. Loughty, Vice-Chair Joanne Flanagan, Secretary Producer Group ,-.,., AMP Incorporated Name of Representati
39、ve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Edward Kell Charles Bnl 7 AT* Xerox Corporation Gary S. Robinson (AA.) . Dwight McBain 3M Company Roy Pierce (Alt.) Edre T. Morioka Paul D. Jahnke (Alt.) Consumers Group Boeing Company . C
40、atherine Howells Andrea Vanosdoll (Alt.) Eastman Kodak Company . James Converse General Services Administration Michael Nier (A%.) Douglas Arai Larry L. Jackson (A$.) Guide International Inc . Frank Kirshenbaum *Hughes Harold Kuneke (Alt.) Aircraft Company Harold Zebrack National Communications Nort
41、hern Telecom Inc Systems . Dennis Bodson . Mel Woinsky Recognition Tech Users Association Subhash Pate1 (Alt.) . Herbert P. Schantz G. Edwin Hale (Aft.) Share Inc. . Gary Ainsworth David Thewis (Alt.) U. S. Department of Defense . William Rinehuls Energy C. J. Pasquariello (AR.) U. S. Department of
42、. Atton Cox Lawrence A. Wasson (Alt.) Wintergreen Information Services John Wheeler General Interest Group American Nuclear Societv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine C. Main , Sally Hartzell (Alt.) Assn. of the Institute for Certifica
43、tion of Computer Professionals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kenneth Zemrowski Nat1 Institute of Standards and Technology . . . . . . . . . . . . . . . . . . . Robert E. Ro
44、untree Neville Micharl Hogan (A#.) - the rules for interpreting the meaning of a program and its data. 1.2.2 Exclusions This Standard does not specify: - the mechanism by which programs are transformed for use on computing systems; - the operations required for setup and control of the use of progra
45、ms on computing systems; - the method of transcription of programs or their input or output data to or from a storage medium; - the program and Forth system behavior when the rules of this Standard fail to establish an interpretation; - the size or complexity of a program and its data that will exce
46、ed the capacity of any specific computing system or the capability of a particular Forth system; - the physical properties of input/output records, files, and units; - the physical properties and implementation of storage. 1 _ _. _ - _- _- .- ._-_ _-_-,._- ._.,.“_ _ZY ._ ANSI X3.21 5-1994 1.3 Docume
47、nt organization 1.3.1 Word sets This Standard groups Forth words and capabilities into word sets under a name indicating some shared aspect, typically their common functional area. Each word set may have an extension, containing words that offer additional functionality. These words are not required
48、 in an implementation of the word set. The “Core” word set, defined in sections 1 through 6, contains the required words and capabilities of a Standard System. The other word sets, defined in sections 7 through 17, are optional, making it possible to provide Standard Systems with tailored levels of
49、functionality. 1.3.1.1 Text sections Within each word set, section 1 contains introductory and explanatory material and section 2 introduces terms and notation used throughout the Standard. There are no requirements in these sections. Sections 3 and 4 contain the usage and documentation requirements, respectively, for Standard Systems and Programs, while section 5 specifies their labeling. 1.3.1.2 Glossary sections Section 6 of each word set specifies the required behavior of the definitions in the word set and the extensions word set. 1.3.2 Annexes The annex
