svn commit: r210167 - head/share/doc/psd/15.yacc
Ed Maste
emaste at FreeBSD.org
Fri Jul 16 17:01:37 UTC 2010
Author: emaste
Date: Fri Jul 16 17:01:36 2010
New Revision: 210167
URL: http://svn.freebsd.org/changeset/base/210167
Log:
Rename documentation source files to avoid filesystem case and restricted
filename issues when checking out the source on other operating systems.
I've verified the generated paper.ascii is identical before and after the
change.
Added:
head/share/doc/psd/15.yacc/ss10
- copied unchanged from r210153, head/share/doc/psd/15.yacc/ssA
head/share/doc/psd/15.yacc/ss11
- copied unchanged from r210153, head/share/doc/psd/15.yacc/ssB
head/share/doc/psd/15.yacc/ss_
- copied unchanged from r210153, head/share/doc/psd/15.yacc/ss..
Deleted:
head/share/doc/psd/15.yacc/ss..
head/share/doc/psd/15.yacc/ssA
head/share/doc/psd/15.yacc/ssB
Modified:
head/share/doc/psd/15.yacc/Makefile
Modified: head/share/doc/psd/15.yacc/Makefile
==============================================================================
--- head/share/doc/psd/15.yacc/Makefile Fri Jul 16 14:31:24 2010 (r210166)
+++ head/share/doc/psd/15.yacc/Makefile Fri Jul 16 17:01:36 2010 (r210167)
@@ -2,8 +2,8 @@
# $FreeBSD$
VOLUME= psd/15.yacc
-SRCS= stubs ss.. ss0 ss1 ss2 ss3 ss4 ss5 ss6 ss7 ss8 ss9 \
- ssA ssB ssa ssb ssc ssd
+SRCS= stubs ss_ ss0 ss1 ss2 ss3 ss4 ss5 ss6 ss7 ss8 ss9 \
+ ss10 ss11 ssa ssb ssc ssd
EXTRA= ref.bib
MACROS= -ms
USE_REFER=
Copied: head/share/doc/psd/15.yacc/ss10 (from r210153, head/share/doc/psd/15.yacc/ssA)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/share/doc/psd/15.yacc/ss10 Fri Jul 16 17:01:36 2010 (r210167, copy of r210153, head/share/doc/psd/15.yacc/ssA)
@@ -0,0 +1,221 @@
+.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions are
+.\" met:
+.\"
+.\" Redistributions of source code and documentation must retain the above
+.\" copyright notice, this list of conditions and the following
+.\" disclaimer.
+.\"
+.\" Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\"
+.\" This product includes software developed or owned by Caldera
+.\" International, Inc. Neither the name of Caldera International, Inc.
+.\" nor the names of other contributors may be used to endorse or promote
+.\" products derived from this software without specific prior written
+.\" permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" @(#)ssA 8.1 (Berkeley) 6/8/93
+.\"
+.\" $FreeBSD$
+.SH
+10: Advanced Topics
+.PP
+This section discusses a number of advanced features
+of Yacc.
+.SH
+Simulating Error and Accept in Actions
+.PP
+The parsing actions of error and accept can be simulated
+in an action by use of macros YYACCEPT and YYERROR.
+YYACCEPT causes
+.I yyparse
+to return the value 0;
+YYERROR causes
+the parser to behave as if the current input symbol
+had been a syntax error;
+.I yyerror
+is called, and error recovery takes place.
+These mechanisms can be used to simulate parsers
+with multiple endmarkers or context-sensitive syntax checking.
+.SH
+Accessing Values in Enclosing Rules.
+.PP
+An action may refer to values
+returned by actions to the left of the current rule.
+The mechanism is simply the same as with ordinary actions,
+a dollar sign followed by a digit, but in this case the
+digit may be 0 or negative.
+Consider
+.DS
+sent : adj noun verb adj noun
+ { \fIlook at the sentence\fR . . . }
+ ;
+
+adj : THE { $$ = THE; }
+ | YOUNG { $$ = YOUNG; }
+ . . .
+ ;
+
+noun : DOG
+ { $$ = DOG; }
+ | CRONE
+ { if( $0 == YOUNG ){
+ printf( "what?\en" );
+ }
+ $$ = CRONE;
+ }
+ ;
+ . . .
+.DE
+In the action following the word CRONE, a check is made that the
+preceding token shifted was not YOUNG.
+Obviously, this is only possible when a great deal is known about
+what might precede the symbol
+.I noun
+in the input.
+There is also a distinctly unstructured flavor about this.
+Nevertheless, at times this mechanism will save a great
+deal of trouble, especially when a few combinations are to
+be excluded from an otherwise regular structure.
+.SH
+Support for Arbitrary Value Types
+.PP
+By default, the values returned by actions and the lexical analyzer are integers.
+Yacc can also support
+values of other types, including structures.
+In addition, Yacc keeps track of the types, and inserts
+appropriate union member names so that the resulting parser will
+be strictly type checked.
+The Yacc value stack (see Section 4)
+is declared to be a
+.I union
+of the various types of values desired.
+The user declares the union, and associates union member names
+to each token and nonterminal symbol having a value.
+When the value is referenced through a $$ or $n construction,
+Yacc will automatically insert the appropriate union name, so that
+no unwanted conversions will take place.
+In addition, type checking commands such as
+.I Lint\|
+.[
+Johnson Lint Checker 1273
+.]
+will be far more silent.
+.PP
+There are three mechanisms used to provide for this typing.
+First, there is a way of defining the union; this must be
+done by the user since other programs, notably the lexical analyzer,
+must know about the union member names.
+Second, there is a way of associating a union member name with tokens
+and nonterminals.
+Finally, there is a mechanism for describing the type of those
+few values where Yacc can not easily determine the type.
+.PP
+To declare the union, the user includes in the declaration section:
+.DS
+%union {
+ body of union ...
+ }
+.DE
+This declares the Yacc value stack,
+and the external variables
+.I yylval
+and
+.I yyval ,
+to have type equal to this union.
+If Yacc was invoked with the
+.B \-d
+option, the union declaration
+is copied onto the
+.I y.tab.h
+file.
+Alternatively,
+the union may be declared in a header file, and a typedef
+used to define the variable YYSTYPE to represent
+this union.
+Thus, the header file might also have said:
+.DS
+typedef union {
+ body of union ...
+ } YYSTYPE;
+.DE
+The header file must be included in the declarations
+section, by use of %{ and %}.
+.PP
+Once YYSTYPE is defined,
+the union member names must be associated
+with the various terminal and nonterminal names.
+The construction
+.DS
+< name >
+.DE
+is used to indicate a union member name.
+If this follows
+one of the
+keywords %token,
+%left, %right, and %nonassoc,
+the union member name is associated with the tokens listed.
+Thus, saying
+.DS
+%left <optype> \'+\' \'\-\'
+.DE
+will cause any reference to values returned by these two tokens to be
+tagged with
+the union member name
+.I optype .
+Another keyword, %type, is
+used similarly to associate
+union member names with nonterminals.
+Thus, one might say
+.DS
+%type <nodetype> expr stat
+.DE
+.PP
+There remain a couple of cases where these mechanisms are insufficient.
+If there is an action within a rule, the value returned
+by this action has no
+.I "a priori"
+type.
+Similarly, reference to left context values (such as $0 \- see the
+previous subsection ) leaves Yacc with no easy way of knowing the type.
+In this case, a type can be imposed on the reference by inserting
+a union member name, between < and >, immediately after
+the first $.
+An example of this usage is
+.DS
+rule : aaa { $<intval>$ = 3; } bbb
+ { fun( $<intval>2, $<other>0 ); }
+ ;
+.DE
+This syntax has little to recommend it, but the situation arises rarely.
+.PP
+A sample specification is given in Appendix C.
+The facilities in this subsection are not triggered until they are used:
+in particular, the use of %type will turn on these mechanisms.
+When they are used, there is a fairly strict level of checking.
+For example, use of $n or $$ to refer to something with no defined type
+is diagnosed.
+If these facilities are not triggered, the Yacc value stack is used to
+hold
+.I int' s,
+as was true historically.
Copied: head/share/doc/psd/15.yacc/ss11 (from r210153, head/share/doc/psd/15.yacc/ssB)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/share/doc/psd/15.yacc/ss11 Fri Jul 16 17:01:36 2010 (r210167, copy of r210153, head/share/doc/psd/15.yacc/ssB)
@@ -0,0 +1,63 @@
+.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions are
+.\" met:
+.\"
+.\" Redistributions of source code and documentation must retain the above
+.\" copyright notice, this list of conditions and the following
+.\" disclaimer.
+.\"
+.\" Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\"
+.\" This product includes software developed or owned by Caldera
+.\" International, Inc. Neither the name of Caldera International, Inc.
+.\" nor the names of other contributors may be used to endorse or promote
+.\" products derived from this software without specific prior written
+.\" permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" @(#)ssB 8.1 (Berkeley) 6/8/93
+.\"
+.\" $FreeBSD$
+.SH
+11: Acknowledgements
+.PP
+Yacc owes much to a
+most stimulating collection of users, who have goaded
+me beyond my inclination, and frequently beyond my
+ability, in their endless search for ``one more feature''.
+Their irritating unwillingness to learn how to
+do things my way has usually led to my doing things their way;
+most of the time, they have been right.
+B. W. Kernighan, P. J. Plauger, S. I. Feldman, C. Imagna,
+M. E. Lesk,
+and A. Snyder will recognize some of their ideas in the current version
+of Yacc.
+C. B. Haley contributed to the error recovery algorithm.
+D. M. Ritchie, B. W. Kernighan, and M. O. Harris helped translate this document into English.
+Al Aho also deserves special credit for bringing
+the mountain to Mohammed, and other favors.
+.\" .SG "MH-1273-SCJ-unix"
+.bp
+.[
+$LIST$
+.]
+.bp
Copied: head/share/doc/psd/15.yacc/ss_ (from r210153, head/share/doc/psd/15.yacc/ss..)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/share/doc/psd/15.yacc/ss_ Fri Jul 16 17:01:36 2010 (r210167, copy of r210153, head/share/doc/psd/15.yacc/ss..)
@@ -0,0 +1,94 @@
+.\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions are
+.\" met:
+.\"
+.\" Redistributions of source code and documentation must retain the above
+.\" copyright notice, this list of conditions and the following
+.\" disclaimer.
+.\"
+.\" Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\"
+.\" This product includes software developed or owned by Caldera
+.\" International, Inc. Neither the name of Caldera International, Inc.
+.\" nor the names of other contributors may be used to endorse or promote
+.\" products derived from this software without specific prior written
+.\" permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+.\" OR OTHERWISE) RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" @(#)ss.. 8.1 (Berkeley) 6/8/93
+.\"
+.\" $FreeBSD$
+.EH 'PSD:15-%''Yacc: Yet Another Compiler-Compiler'
+.OH 'Yacc: Yet Another Compiler-Compiler''PSD:15-%'
+.\".RP
+.ND "July 31, 1978"
+.TL
+Yacc:
+Yet Another Compiler-Compiler
+.AU "MH 2C-559" 3968
+Stephen C. Johnson
+AT&T Bell Laboratories
+Murray Hill, New Jersey 07974
+.AI
+.AB
+.PP
+Computer program input generally has some structure;
+in fact, every computer program that does input can be thought of as defining
+an ``input language'' which it accepts.
+An input language may be as complex as a programming language, or as simple as
+a sequence of numbers.
+Unfortunately, usual input facilities
+are limited, difficult to use,
+and often are lax about checking their inputs for validity.
+.PP
+Yacc provides a general tool for describing
+the input to a computer program.
+The Yacc user specifies the structures
+of his input, together with code to be invoked as
+each such structure is recognized.
+Yacc turns such a specification into a subroutine that
+handles the input process;
+frequently, it is convenient and appropriate to have most
+of the flow of control in the user's application
+handled by this subroutine.
+.PP
+The input subroutine produced by Yacc calls a user-supplied routine to
+return the next basic input item.
+Thus, the user can specify his input in terms of individual input characters, or
+in terms of higher level constructs such as names and numbers.
+The user-supplied routine may also handle idiomatic features such as
+comment and continuation conventions, which typically defy easy grammatical specification.
+.PP
+Yacc is written in portable C.
+The class of specifications accepted is a very general one: LALR(1)
+grammars with disambiguating rules.
+.PP
+In addition to compilers for C, APL, Pascal, RATFOR, etc., Yacc
+has also been used for less conventional languages,
+including a phototypesetter language, several desk calculator languages, a document retrieval system,
+and a Fortran debugging system.
+.AE
+.\" .OK
+.\"Computer Languages
+.\"Compilers
+.\"Formal Language Theory
+.\" .CS 23 11 34 0 0 8
More information about the svn-src-head
mailing list