Commit ad184565 authored by pknaggs's avatar pknaggs
Browse files

Added x:stoftos (F>S S>F) 

Changed F94 for F12
Added word number for DFFIELD: FFIELD: FTRUNC FVALUE SFFIELD:
Changed child stack effect for DFFIELD: FFIELD: SFFIELD:
Corrected typo for F.
Minor alteration to rational for FATAN2, FEXPM1
parent f970d6e9

float.tex

+92 −38
Original line number Diff line number Diff line 
% !TeX root = forth.tex

% !TeX spell check = en_US



\chapter{The optional Floating-Point word set} % 12

\wordlist{floating}
@@ -264,6 +267,10 @@ See: 
	(\wref{floating:Fd}{F.},

	 \wref{floating:FEd}{FE.},

	 \wref{floating:FSd}{FS.}).

\item \place{x:stoftos}{\param{n} can't be precisely represented as

	\emph{float} in \wref{floating:StoF}{S>F};}

\item \place{x:stoftos}{integer part of \emph{float} can't be represented

	by \param{n} in \wref{floating:FtoS}{F>S}.}

\end{itemize}



\subsubsection{Other system documentation} % 12.4.1.3
@@ -297,8 +304,8 @@ See: 


\section{Compliance and labeling} % 12.5



\cbstart\patch{F94}

\subsection[Forth systems]{ANS\strike{3.5}{25} Forth systems} % 12.5.1

\cbstart\patch{F12}

\subsection[Forth-\snapshot systems]{Forth-\snapshot\strike{-1}{25} systems} % 12.5.1

\cbend



The phrase ``Providing the Floating-Point word set'' shall be
@@ -314,8 +321,8 @@ The phrase ``Providing the Floating-Point Extensions word set'' shall 
be appended to the label of any Standard System that provides all of

the Floating-Point and Floating-Point Extensions word sets.



\cbstart\patch{F94}

\subsection[Forth programs]{ANS\strike{3.5}{25} Forth programs} % 12.5.2

\cbstart\patch{F12}

\subsection[Forth-\snapshot programs]{Forth-\snapshot\strike{-1}{25} programs} % 12.5.2

\cbend



The phrase ``Requiring the Floating-Point word set'' shall be
@@ -376,7 +383,7 @@ word sets. 
		does the text interpreter since the latter defines rules for

		composing source programs whereas \word{toFLOAT} defines rules

		for accepting data. \word{toFLOAT} is defined as broadly as is

		feasible to permit input of data from \remove{F94}{ANS} Forth systems as well

		feasible to permit input of data from Forth\place{F12}{-\snapshot} systems as well

		as other widely used standard programming environments.



		This is a synthesis of common FORTRAN practice. Embedded spaces
@@ -385,7 +392,7 @@ word sets. 


		While \word{toFLOAT} is not required to treat a string of blanks

		as zero, this behavior is strongly encouraged, since a future

		version of \replace{F94}{ANS Forth}{this standard} may include such a requirement.

		version of this standard may include such a requirement.

	\end{rationale}

\end{worddef}
@@ -806,7 +813,7 @@ word sets. 


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



\begin{worddef}{}{DFFIELD:}[d-f-field-colon][X:structures]

\begin{worddef}{1207}[40]{DFFIELD:}[d-f-field-colon][X:structures]

\item \stack{n_1 "<spaces>name"}{n_2}



	Skip leading space delimiters. Parse \param{name} delimited by
@@ -818,18 +825,18 @@ word sets. 
	given below.



\execute[name]

\cbstart\patch{ed11}

	\stack{a-addr_{\sout{1}}}{\sout{a}\uline{df}-addr_{\sout{2}}}

\cbstart\patch{ed12}

	\stack{\sout{a-}addr_{\uline{1}}}{\sout{df-}addr_{\uline{2}}}

\cbend



	Add the \param{offset} calculated during the compile time action to

\cbstart\param{a-addr_{\sout{1}}}\cbend\ 

\cbstart\param{\sout{a-}addr_{\uline{1}}}\cbend\ 

	giving the double-float aligned address

\cbstart\param{\sout{a}\uline{df}-addr_{\sout{2}}}.\cbend

\cbstart\param{\sout{df-}addr_{\uline{2}}}.\cbend



\see \wref{facility:+FIELD}{+FIELD},

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE},

	\wref{facility:END-STRUCTURE}{END-STRUCTURE}, \linebreak

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE}, \\

	\wref{facility:END-STRUCTURE}{END-STRUCTURE},

	\rref{facility:FIELD:}{}.

\end{worddef}
@@ -862,7 +869,7 @@ word sets. 
\end{worddef}





\begin{worddef}[Fd]{1427}{F.}[f-dot]

\begin{worddef}[Fd]{1427}{F.{}}[f-dot]

\item \stack{}{} \stack[F]{r}{} or

	\stack{r}{}
@@ -879,11 +886,36 @@ word sets. 
	\rref{floating:Fd}{}.



	\begin{rationale} % A.12.6.1.1427 F.

		For example, \texttt{1E3} \word{Fd} displays \texttt{1000.} .

		For example, \texttt{1E3} \replace{ed12}{\textbf{\texttt{F}}}{ \word{Fd}} displays \texttt{1000.} .

	\end{rationale}

\end{worddef}





% ========== x:stoftos ==========



\begin{worddef*}[FtoS]{1471}{F>S}[F to S][x:stoftos]

\item \stack{}{n} \stack[F]{r}{} or \stack{r}{n}



	\uline{\param{n} is the single-cell signed-integer equivalent of the

	integer portion of \param{r}.  The fractional portion of

	\param{r} is discarded.  An ambiguous condition exists if

	the integer portion of \param{r} cannot be precisely

	represented as a single-cell signed integer.}



\note \uline{Rounding the floating-point value prior to calling \word{FtoS} is

	advised.}



\see \uline{\wref{floating:StoF}{}.}



	\begin{implement}

		\uline{\word{:} \word{FtoS} \word{p} r -{}- n )} \\

		\tab \uline{\word{FtoD} \word[double]{DtoS}} \\

		\uline{\word{;}}

	\end{implement}

\end{worddef*}



% ==============================



\begin{worddef}{1474}{FABS}[f-abs]

\item \stack[F]{r_1}{r_2} or

	\stack{r_1}{r_2}
@@ -981,11 +1013,12 @@ word sets. 
		Thus the phrase \word{FSINCOS} \word{F/} is functionally

		equivalent to \word{FTAN}, but is useful over only a limited

		and discontinuous range of angles, whereas \word{FSINCOS} and

		\word{FATAN2} are useful for all angles. This ordering has

		\word{FATAN2} are useful for all angles.

\remove{ed12}{This ordering has

		been found convenient for nearly two decades, and has the

		added benefit of being easy to remember. A corollary to this

		observation is that vectors in general should appear on the

		stack in this order.

		stack in this order.}



		The argument order for \word{FATAN2} is the same, converting a

		vector in the conventional representation to a scalar angle.
@@ -1210,14 +1243,14 @@ word sets. 
		This function allows accurate computation when its arguments

		are close to zero, and provides a useful base for the standard

		exponential functions. Hyperbolic functions such as

		\textsf{cosh($x$)} can be efficiently and accurately

\textsf{\replace{ed12}{cosh}{sinh}($x$)} can be efficiently and accurately

		implemented by using \word{FEXPM1}; accuracy is lost in this

		function for small values of $x$ if the word \word{FEXP} is

		used.



		An important application of this word is in finance; say a loan

		is repaid at 15\% per year; what is the daily rate? On a computer

		with single precision (six decimal digit) accuracy:

		with single\place{ed12}{-}precision (six decimal digit) accuracy:



		\begin{enumerate}

		\item[1.] Using \word{FLN} and \word{FEXP}:
@@ -1227,7 +1260,7 @@ word sets. 
			form the exponent using \word{FEXP} = 1.00038, and \\

			subtract one (1) and convert to percentage = 0.038\%.

		\end{enumerate}

		Thus we only have two digit accuracy.

		Thus we only have two\place{ed12}{-}digit accuracy.

		\begin{enumerate}

		\item[2.] Using \word{FLNP1} and \word{FEXPM1}:
@@ -1239,9 +1272,9 @@ word sets. 
			\word{FEXPM1} = 3.82983E-4, and \\

			convert to percentage = 0.0382983\%.

		\end{enumerate}

		This is full six digit accuracy.

		This is full six\place{ed12}{-}digit accuracy.



		The presence of this word allows the hyperbolic functions to

		\replace{ed12}{The presence of this}{ This} \remove{ed12}{word} allows the hyperbolic functions to

		be computed with usable accuracy. For example, the hyperbolic

		sine can be defined as:
@@ -1257,7 +1290,7 @@ word sets. 


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



\begin{worddef}{}{FFIELD:}[f-field-colon][X:structures]

\begin{worddef}{1517}{FFIELD:}[f-field-colon][X:structures]

\item \stack{n_1 "<spaces>name"}{n_2}



	Skip leading space delimiters. Parse \param{name} delimited by
@@ -1268,18 +1301,18 @@ word sets. 
	given below.



\execute[name]

\cbstart\patch{ed11}

	\stack{a-addr_{\sout{1}}}{\sout{a}\uline{f}-addr_{\sout{2}}}

\cbstart\patch{ed12}

	\stack{\sout{a-}addr_{\uline{1}}}{\sout{f-}addr_{\uline{2}}}

\cbend



	Add the \param{offset} calculated during the compile time action to

\cbstart\param{a-addr_{\sout{1}}}\cbend\ 

\cbstart\param{\sout{a-}addr_{\uline{1}}}\cbend\ 

	giving the float aligned address

\cbstart\param{\sout{a}\uline{f}-addr_{\sout{2}}}.\cbend

\cbstart\param{\sout{f-}addr_{\uline{2}}}.\cbend



\see \wref{facility:+FIELD}{+FIELD},

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE},

	\wref{facility:END-STRUCTURE}{END-STRUCTURE}, \linebreak

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE}, \\

	\wref{facility:END-STRUCTURE}{END-STRUCTURE},

	\rref{facility:FIELD:}{}.

\end{worddef}
@@ -1408,7 +1441,7 @@ word sets. 


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



\begin{worddef}{}{FTRUNC}[f-trunc][x:ftrunc]

\begin{worddef}{1627}{FTRUNC}[f-trunc][x:ftrunc]

\item \stack[F]{r_1}{r_2} or \stack{r_1}{r_2}



	Round \param{r_1} to an integral value using the ``round
@@ -1446,7 +1479,7 @@ word sets. 


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



\begin{worddef}{}{FVALUE}[f-value][X:fvalue]

\begin{worddef}{1628}{FVALUE}[f-value][X:fvalue]

\item \stack[F]{r}{} \stack{"<spaces>name"}{} or

	\stack{r "<spaces>name"}{}
@@ -1543,6 +1576,27 @@ word sets. 
\end{worddef}





% ========== x:stoftos ==========



\begin{worddef*}[StoF]{2175}{S>F}[S to F][x:stoftos]

\item \stack{n}{} \stack[F]{}{r} or \stack{n}{r}



	\uline{\param{r} is the floating-point equivalent of the single-cell

	value \param{n}.  An ambiguous condition exists if \param{n}

	can not be precisely represented as a floating-point value.}



\see \uline{\wref{floating:FtoS}{F>S}.}



	\begin{implement}

		\uline{\word{:} \word{StoF} \word{p} n -{}- r )} \\

		\tab \uline{\word{StoD} \word{DtoF}} \\

		\uline{\word{;}}

	\end{implement}

\end{worddef*}



% ==============================





\begin{worddef}{2200}{SET-PRECISION}

\item \stack{u}{}
@@ -1607,7 +1661,7 @@ word sets. 


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



\begin{worddef}{}{SFFIELD:}[s-f-field-colon][X:structures]

\begin{worddef}{2206}[40]{SFFIELD:}[s-f-field-colon][X:structures]

\item \stack{n_1 "<spaces>name"}{n_2}



	Skip leading space delimiters. Parse \param{name} delimited by
@@ -1619,18 +1673,18 @@ word sets. 
	given below.



\execute[name]

\cbstart\patch{ed11}

	\stack{a-addr_{\sout{1}}}{\sout{a}\uline{sf}-addr_{\sout{2}}}

\cbstart\patch{ed12}

	\stack{\sout{a-}addr_{\uline{1}}}{\sout{sf-}addr_{\uline{2}}}

\cbend



	Add the \param{offset} calculated during the compile time action to

\cbstart\param{a-addr_{\sout{1}}}\cbend\ 

\cbstart\param{\sout{a-}addr_{\uline{1}}}\cbend\ 

	giving the single-float aligned address

\cbstart\param{\sout{a}\uline{sf}-addr_{\sout{2}}}.\cbend

\cbstart\param{\sout{sf-}addr_{\uline{2}}}.\cbend



\see \wref{facility:+FIELD}{+FIELD},

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE},

	\wref{facility:END-STRUCTURE}{END-STRUCTURE}, \linebreak

	\wref{facility:BEGIN-STRUCTURE}{BEGIN-STRUCTURE}, \\

	\wref{facility:END-STRUCTURE}{END-STRUCTURE},

	\rref{facility:FIELD:}{}.

\end{worddef}