Commit ef991087 authored by pknaggs's avatar pknaggs
Browse files

Added reference to Rational in introduction 

Removed x:enhanced-locals markup
Replaced F94 with F12
Added implementation of LOCALS| (taken from rational introduction)
Added rational for LOCALS| (taken from rational introduction)
Added word number for {:
Minor revisions to definition and rational of {:
parent 1c54820f

locals.tex

+43 −22
Original line number Diff line number Diff line 
% !TeX root = forth.tex

% !TeX spellcheck = en_US



\chapter{The optional Locals word set} % 13

\wordlist{local}



\section{Introduction} % 13.1

\label{locals:intro}



See: \xref[Annex A.13 The Locals Word Set]{rat:local}.

\cbstart\patch{ed12}

See: \xref[Annex A.13 The Locals Word Set]{rat:local}.\strike{4}{175}

\cbend



\section{Additional terms and notation} % 13.2
@@ -109,7 +115,7 @@ shall take the following actions at compile time: 
\end{enumerate}



A system implementing the Locals word set shall support the

declaration of at least \replace{x:enhanced-locals}{eight}{sixteen} locals in a definition.

declaration of at least sixteen locals in a definition.





\subsubsection{Syntax restrictions} % 13.3.3.2
@@ -141,7 +147,7 @@ syntaxes for local declarations with the following restrictions: 
	(tick), \word[core]{[']}, or \word[core]{FIND}, shall not be

	used with local names;



\item A program that declares more than \replace{x:enhanced-locals}{eight}{sixteen} locals in a single

\item A program that declares more than sixteen locals in a single

	definition has an environmental dependency;



\item Locals may be accessed or updated within control structures,
@@ -170,10 +176,10 @@ See: \xref[3.4 The Forth text interpreter]{usage:command}. 
\begin{itemize}

\item executing a named \emph{local} while in interpretation state

	(\wref{local:LOCAL}{(LOCAL)});

\item \place{x:enhanced-locals}{a local name ends in ``\texttt{:}'', ``\texttt{[}'', ``\texttt{\textasciicircum}'';}

\item \place{x:enhanced-locals}{a local name is a single non-alphabetic character;}

\item \place{x:enhanced-locals}{the text between \word{b:} and \texttt{:\}} extends over more than one line;}

\item \place{x:enhanced-locals}{\word{b:} \ldots{} \texttt{:\}} is used more than once in a word.}

\item a local name ends in ``\texttt{:}'', ``\texttt{[}'', ``\texttt{\textasciicircum}'';

\item a local name is a single non-alphabetic character;

\item the text between \word{b:} and \texttt{:\}} extends over more than one line;

\item \word{b:} \ldots\ \texttt{:\}} is used more than once in a word.

\end{itemize}



\subsubsection{Other system documentation} % 13.4.1.3
@@ -186,7 +192,7 @@ See: \xref[3.4 The Forth text interpreter]{usage:command}. 
\subsubsection{Environmental dependencies} % 13.4.2.1

\label{locals:environment}

\begin{itemize}

\item declaring more than \replace{x:enhanced-locals}{eight}{sixteen} locals in a single definition

\item declaring more than sixteen locals in a single definition

	(\xref[13.3.3 Processing locals]{local:locals}).

\end{itemize}
@@ -198,8 +204,8 @@ See: \xref[3.4 The Forth text interpreter]{usage:command}. 


\section{Compliance and labeling} % 13.5



\cbstart\patch{F94}

\subsection[Forth systems]{ANS\strike{3.5}{25} Forth systems} % 13.5.1

\cbstart\patch{F12}

\subsection[Forth-\snapshot systems]{Forth-\snapshot\strike{-1}{25} systems} % 13.5.1

\cbend



The phrase ``Providing the Locals word set'' shall be appended to
@@ -214,8 +220,8 @@ The phrase ``Providing the Locals Extensions word set'' shall be 
appended to the label of any Standard System that provides all of

the Locals and Locals Extensions word sets.



\cbstart\patch{F94}

\subsection[Forth programs]{ANS\strike{3.5}{25} Forth programs} % 13.5.2

\cbstart\patch{F12}

\subsection[Forth-\snapshot programs]{Forth-\snapshot\strike{-1}{25} programs} % 13.5.2

\cbend



The phrase ``Requiring the Locals word set'' shall be appended to
@@ -319,19 +325,32 @@ to provide all of the Locals and Locals Extensions word sets. 
	each local will return its value. The value of a local may be

	changed using \wref{core:TO}{TO}.



\see \rref{local:LOCALS}{}.

\see \remove{ed12}{\rref{local:LOCALS}{}.}



	\begin{implement}

\cbstart\patch{ed12}

	\uline{\word{:} \word{LOCALS} \word{p} "name{\ldots}name |" -{}- )} \\

	\tab \uline{\word{BEGIN}} \\

	\tab~ \uline{\word{BL} \word{WORD} ~ \word{COUNT} \word{OVER} \word{C@}} \\

	\tab~ \uline{\word{[CHAR]} | \word{-} \word{OVER} 1 \word{-} \word{OR} ~ \word{WHILE}} \\

	\tab~ \uline{\word[local]{LOCAL}} \\

	\tab \uline{\word{REPEAT} \word{2DROP} ~ 0 0 \word{LOCAL}} \\

	\uline{\word{;} \word{IMMEDIATE}}

\cbend

	\end{implement}



	\begin{rationale} % A.13.6.2.1795 LOCALS|

\remove{ed12}{%

		A possible implementation of this word and an example of usage

		is given in \ref{rat:local}, above. It is intended as an

		example only; any implementation yielding the described

		semantics is acceptable.

		semantics is acceptable.}

	\end{rationale}

\end{worddef}



\newpage

% -------------------------------------------------------------------



\begin{worddef*}[b:]{}{\brace:}[brace-colon][x:enhanced-locals]

\begin{worddef}[b:]{2550}{\brace:}[brace-colon][x:enhanced-locals]

\interpret

	Interpretation semantics for this word are undefined.
@@ -371,7 +390,7 @@ to provide all of the Locals and Locals Extensions word sets. 
	\item[\arg{val}] names are uninitialized.

	\end{list}



	\arg{val} names and \arg{arg} names have the execution semantics

	\arg{val} \remove{ed12}{names} and \arg{arg} names have the execution semantics

		given below.



\execute[name]
@@ -384,7 +403,8 @@ to provide all of the Locals and Locals Extensions word sets. 
\runtime[\word{TO} \param{name}]

	\stack{x}{}



	Assign the value \param{x} to the local \param{name}.

	\replace{ed12}{Assign the value \param{x} to the local \param{name}.}{%

	Set \param{name} to the value \param{x}.}



\see \xref[2.2 Notation]{notations},

	\wref{core:VALUE}{},
@@ -392,7 +412,7 @@ to provide all of the Locals and Locals Extensions word sets. 
	\rref{local:b:}{}.



	\begin{rationale}

		The Forth 94 Technical Committee where unable to identify any common

		The Forth 94 Technical Committee \replace{ed12}{where}{were} unable to identify any common

		practice for locals.  They provided a way to define locals and a method

		of parsing them in the hope that a common practice would emerge.
@@ -474,7 +494,8 @@ to provide all of the Locals and Locals Extensions word sets. 
\tab\,\word{2DROP} define-locals \\

\word{;} \word{IMMEDIATE}

	\end{implement}

\end{worddef*}

\end{worddef}



\endinput