$Revision: 1.3 $
$Date: 2002/06/12 11:18:29 $
productionset — A set of EBNF productions
productionset ::= ((title,titleabbrev?)?, (production|productionrecap)+)
This element is only available if you are using the EBNF Module.
A ProductionSet is a collection of Extended Backus-Naur Form (EBNF) Productions.
EBNF is a notation for describing the grammar of context-free languages. Even if you aren't conversant in the programming language concepts of context-free languages and grammars, it's not really as hard to understand as it sounds.
A set of EBNF productions describes the legal arrangements of tokens in a language. Consider arithmetic expressions as a simple example.
The expression “3 + 4” is valid and so is “3 + 4 - 5”, but “3 - + - 4” is not, nor is “3 + 4 6”. We can use EBNF to describe all the possible legal arrangements:
Arithemetic Expressions | ||||||||||||||||||||
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Division by Zero
Division by zero is an error. Constraints, such as this one, are used to express conditions that cannot be expressed in the grammar.
Formatted as a displayed block. The detailed processing expecations with respect to individual productions, left-hand sides, and right-hand sides are quite complex.
Productions should be numbered.
These elements contain productionset: appendix, article, bibliodiv, bibliography, blockquote, callout, chapter, glossary, glossdiv, index, listitem, msgexplan, msgtext, partintro, preface, procedure, refsect1, refsect2, refsect3, refsection, refsynopsisdiv, sect1, sect2, sect3, sect4, sect5, section, setindex, simplesect, step, taskprerequisites, taskrelated, tasksummary.
The following elements occur in productionset: production, productionrecap, title, titleabbrev.
<!DOCTYPE simplesect PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"> <simplesect><title>EBNF Grammar</title> <productionset><title>Arithemetic Expressions</title> <production id="ebnf.expression"> <lhs>Expression</lhs> <rhs><nonterminal def="#ebnf.arith">ArithExpression</nonterminal> | <nonterminal def="#ebnf.mult">MultExpression</nonterminal> <lineannotation>Does this grammar actually get precedence right? </lineannotation> </rhs> </production> <production id="ebnf.arith"> <lhs>ArithExpression</lhs> <rhs><nonterminal def="#ebnf.expression">Expression</nonterminal> '+' <nonterminal def="#ebnf.mult">MultExpression</nonterminal> | <nonterminal def="#ebnf.expression">Expression</nonterminal> '-' <nonterminal def="#ebnf.mult">MultExpression</nonterminal> </rhs> </production> <production id="ebnf.mult"> <lhs>MultExpression</lhs> <rhs><nonterminal def="#ebnf.mult">MultExpression</nonterminal> '*' <nonterminal def="#ebnf.mult">MultExpression</nonterminal> | <nonterminal def="#ebnf.mult">MultExpression</nonterminal> '/' <nonterminal def="#ebnf.mult">MultExpression</nonterminal> | <nonterminal def="#ebnf.number">Number</nonterminal> </rhs> <constraint linkend="div0"/> </production> <production id="ebnf.number"> <lhs>Number</lhs> <rhs>[0-9]+</rhs> </production> </productionset> <constraintdef id="div0"> <title>Division by Zero</title> <para>Division by zero is an error.</para> </constraintdef> </simplesect>