[stmt] Move grammar and description of 'condition' up

Author: tkoeppe

source/statements.tex

@@ -24,10 +24,76 @@
 \nontermdef{init-statement}\br
     expression-statement\br
     simple-declaration
+
+\nontermdef{condition}\br
+    expression\br
+    attribute-specifier-seq\opt decl-specifier-seq declarator \terminal{=} initializer-clause\br
+    attribute-specifier-seq\opt decl-specifier-seq declarator braced-init-list
 \end{bnf}
 
 The optional \grammarterm{attribute-specifier-seq} appertains to the respective statement.
 
+\pnum
+\indextext{\idxgram{condition}{s}!rules~for}%
+The rules for \grammarterm{}{condition}{s} apply both to
+\grammarterm{selection-statement}{s} and to the \tcode{for} and \tcode{while}
+statements~(\ref{stmt.iter}). The \grammarterm{}{declarator} shall not
+specify a function or an array. The \grammarterm{decl-specifier-seq} shall not
+define a class or enumeration. If the \tcode{auto} \nonterminal{type-specifier} appears in
+the \nonterminal{decl-specifier-seq},
+the type of the identifier being declared is deduced from the initializer as described in~\ref{dcl.spec.auto}.
+
+\pnum
+\indextext{statement!declaration in \tcode{if}}%
+\indextext{statement!declaration in \tcode{switch}}%
+A name introduced by a declaration in a \grammarterm{}{condition} (either
+introduced by the \grammarterm{decl-specifier-seq} or the
+\grammarterm{}{declarator} of the condition) is in scope from its point of
+declaration until the end of the substatements controlled by the
+condition. If the name is re-declared in the outermost block of a
+substatement controlled by the condition, the declaration that
+re-declares the name is ill-formed.
+\begin{example}
+
+\begin{codeblock}
+if (int x = f()) {
+  int x;            // ill-formed, redeclaration of \tcode{x}
+}
+else {
+  int x;            // ill-formed, redeclaration of \tcode{x}
+}
+\end{codeblock}
+\end{example}
+
+\pnum
+The value of a \grammarterm{}{condition} that is an initialized declaration
+in a statement other than a \tcode{switch} statement is the value of the
+declared variable
+contextually converted to \tcode{bool} (Clause~\ref{conv}).
+If that
+conversion is ill-formed, the program is ill-formed. The value of a
+\grammarterm{}{condition} that is an initialized declaration in a
+\tcode{switch} statement is the value of the declared variable if it has
+integral or enumeration type, or of that variable implicitly converted
+to integral or enumeration type otherwise. The value of a
+\grammarterm{}{condition} that is an expression is the value of the
+expression, contextually converted to \tcode{bool}
+for statements other
+than \tcode{switch};
+if that conversion is ill-formed, the program is
+ill-formed. The value of the condition will be referred to as simply
+``the condition'' where the usage is unambiguous.
+
+\pnum
+If a \grammarterm{}{condition} can be syntactically resolved as either an
+expression or the declaration of a block-scope name, it is interpreted as a
+declaration.
+
+\pnum
+In the \grammarterm{decl-specifier-seq} of a \grammarterm{condition}, each
+\grammarterm{decl-specifier} shall be either a \grammarterm{type-specifier}
+or \tcode{constexpr}.
+
 \rSec1[stmt.label]{Labeled statement}%
 \indextext{statement!labeled}
 
@@ -137,13 +203,6 @@
     \terminal{switch (} init-statement\opt condition \terminal{)} statement
 \end{bnf}
 
-\begin{bnf}
-\nontermdef{condition}\br
-    expression\br
-    attribute-specifier-seq\opt decl-specifier-seq declarator \terminal{=} initializer-clause\br
-    attribute-specifier-seq\opt decl-specifier-seq declarator braced-init-list
-\end{bnf}
-
 See~\ref{dcl.meaning} for the optional \grammarterm{attribute-specifier-seq} in a condition.
 \begin{note}
 An \grammarterm{init-statement} ends with a semicolon.
@@ -176,67 +235,6 @@
 Thus after the \tcode{if} statement, \tcode{i} is no longer in scope.
 \end{example}
 
-\pnum
-\indextext{\idxgram{condition}{s}!rules~for}%
-The rules for \grammarterm{}{condition}{s} apply both to
-\grammarterm{selection-statement}{s} and to the \tcode{for} and \tcode{while}
-statements~(\ref{stmt.iter}). The \grammarterm{}{declarator} shall not
-specify a function or an array. The \grammarterm{decl-specifier-seq} shall not
-define a class or enumeration. If the \tcode{auto} \nonterminal{type-specifier} appears in
-the \nonterminal{decl-specifier-seq},
-the type of the identifier being declared is deduced from the initializer as described in~\ref{dcl.spec.auto}.
-
-\pnum
-\indextext{statement!declaration in \tcode{if}}%
-\indextext{statement!declaration in \tcode{switch}}%
-A name introduced by a declaration in a \grammarterm{}{condition} (either
-introduced by the \grammarterm{decl-specifier-seq} or the
-\grammarterm{}{declarator} of the condition) is in scope from its point of
-declaration until the end of the substatements controlled by the
-condition. If the name is re-declared in the outermost block of a
-substatement controlled by the condition, the declaration that
-re-declares the name is ill-formed.
-\begin{example}
-
-\begin{codeblock}
-if (int x = f()) {
-  int x;            // ill-formed, redeclaration of \tcode{x}
-}
-else {
-  int x;            // ill-formed, redeclaration of \tcode{x}
-}
-\end{codeblock}
-\end{example}
-
-\pnum
-The value of a \grammarterm{}{condition} that is an initialized declaration
-in a statement other than a \tcode{switch} statement is the value of the
-declared variable
-contextually converted to \tcode{bool} (Clause~\ref{conv}).
-If that
-conversion is ill-formed, the program is ill-formed. The value of a
-\grammarterm{}{condition} that is an initialized declaration in a
-\tcode{switch} statement is the value of the declared variable if it has
-integral or enumeration type, or of that variable implicitly converted
-to integral or enumeration type otherwise. The value of a
-\grammarterm{}{condition} that is an expression is the value of the
-expression, contextually converted to \tcode{bool}
-for statements other
-than \tcode{switch};
-if that conversion is ill-formed, the program is
-ill-formed. The value of the condition will be referred to as simply
-``the condition'' where the usage is unambiguous.
-
-\pnum
-If a \grammarterm{}{condition} can be syntactically resolved as either an
-expression or the declaration of a block-scope name, it is interpreted as a
-declaration.
-
-\pnum
-In the \grammarterm{decl-specifier-seq} of a \grammarterm{condition}, each
-\grammarterm{decl-specifier} shall be either a \grammarterm{type-specifier}
-or \tcode{constexpr}.
-
 \rSec2[stmt.if]{The \tcode{if} statement}%
 \indextext{statement!\idxcode{if}}