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+.\" 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
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+.\" 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
+Appendix B: Yacc Input Syntax
+.PP
+This Appendix has a description of the Yacc input syntax, as a Yacc specification.
+Context dependencies, etc., are not considered.
+Ironically, the Yacc input specification language
+is most naturally specified as an LR(2) grammar; the sticky
+part comes when an identifier is seen in a rule, immediately
+following an action.
+If this identifier is followed by a colon, it is the start of the
+next rule; otherwise
+it is a continuation of the current rule, which just happens to have
+an action embedded in it.
+As implemented, the lexical analyzer looks
+ahead after seeing an identifier, and
+decide whether the next token (skipping blanks, newlines, comments, etc.)
+is a colon.
+If so, it returns the token C_IDENTIFIER.
+Otherwise, it returns IDENTIFIER.
+Literals (quoted strings) are also returned as IDENTIFIERS,
+but never as part of C_IDENTIFIERs.
+.sp
+.nf
+.ta .6i 1.2i 1.8i 2.4i 3i 3.6i
+
+ /* grammar for the input to Yacc */
+
+ /* basic entities */
+%token IDENTIFIER /* includes identifiers and literals */
+%token C_IDENTIFIER /* identifier (but not literal) followed by colon */
+%token NUMBER /* [0-9]+ */
+
+ /* reserved words: %type => TYPE, %left => LEFT, etc. */
+
+%token LEFT RIGHT NONASSOC TOKEN PREC TYPE START UNION
+
+%token MARK /* the %% mark */
+%token LCURL /* the %{ mark */
+%token RCURL /* the %} mark */
+
+ /* ascii character literals stand for themselves */
+
+%start spec
+
+%%
+
+spec : defs MARK rules tail
+ ;
+
+tail : MARK { \fIIn this action, eat up the rest of the file\fR }
+ | /* empty: the second MARK is optional */
+ ;
+
+defs : /* empty */
+ | defs def
+ ;
+
+def : START IDENTIFIER
+ | UNION { \fICopy union definition to output\fR }
+ | LCURL { \fICopy C code to output file\fR } RCURL
+ | ndefs rword tag nlist
+ ;
+
+rword : TOKEN
+ | LEFT
+ | RIGHT
+ | NONASSOC
+ | TYPE
+ ;
+
+tag : /* empty: union tag is optional */
+ | \'<\' IDENTIFIER \'>\'
+ ;
+
+nlist : nmno
+ | nlist nmno
+ | nlist \',\' nmno
+ ;
+
+nmno : IDENTIFIER /* NOTE: literal illegal with %type */
+ | IDENTIFIER NUMBER /* NOTE: illegal with %type */
+ ;
+
+ /* rules section */
+
+rules : C_IDENTIFIER rbody prec
+ | rules rule
+ ;
+
+rule : C_IDENTIFIER rbody prec
+ | '|' rbody prec
+ ;
+
+rbody : /* empty */
+ | rbody IDENTIFIER
+ | rbody act
+ ;
+
+act : \'{\' { \fICopy action, translate $$, etc.\fR } \'}\'
+ ;
+
+prec : /* empty */
+ | PREC IDENTIFIER
+ | PREC IDENTIFIER act
+ | prec \';\'
+ ;
+.fi
+.bp