#StartFloat syntax

check/features.frm

@@ -594,7 +594,7 @@ assert result("F", 3) =~ expr("
 *--#] Format_noreset_linelen :
 *--#[ evaluate_symbol :
 #-
-#StartFloat 64
+#StartFloat 64b
 
 Symbol a,b;
 Local PI0 = a*b;
@@ -629,7 +629,7 @@ assert result("EM1") =~ expr("5.77215664901532860607e-01")
 *--#] evaluate_symbol :
 *--#[ evaluate_symbol_pi :
 #-
-#StartFloat 128
+#StartFloat 128b
 
 Local PI = pi_;
 Local EE = ee_;
@@ -647,7 +647,7 @@ assert result("EM") =~ expr("1.0e+00*em_")
 *--#] evaluate_symbol_pi :
 *--#[ evaluate_symbol_ee :
 #-
-#StartFloat 160
+#StartFloat 160b
 
 Local PI = pi_;
 Local EE = ee_;
@@ -665,7 +665,7 @@ assert result("EM") =~ expr("1.0e+00*em_")
 *--#] evaluate_symbol_ee :
 *--#[ evaluate_symbol_em :
 #-
-#StartFloat 192
+#StartFloat 192b
 
 Local PI = pi_;
 Local EE = ee_;

doc/manual/float.tex

@@ -12,10 +12,12 @@ \chapter{Floating point}
 point system. Invoking it will allocate a number of arrays. The instruction 
 has either one or two arguments:
 \begin{verbatim}
-    #startfloat numberofbits <,maximumweight>
+    #startfloat <precision> [,MZV=<maximumweight>]
 \end{verbatim}
-The first argument is mandatory. It tells how many bits of accuracy are 
-required. \FORM{} will round to at least this precision. Because the internal 
+The first argument is mandatory and specifies the desired precision. It must 
+be a positive integer followed by either \texttt{b} (for precision in bits) 
+or \texttt{d} (for precision in decimal digits).
+\FORM{} will round to at least this precision. Because the internal 
 routines work with WORDs the precision will be rounded up to the nearest 
 integer number of WORDs. The second argument is optional for when one wants 
 to work with multiple zeta values (MZVs) or Euler sums. It specifies the 
@@ -65,7 +67,7 @@ \chapter{Floating point}
 
 The following example shows some work with Multiple Zeta Values (MZV's):
 \begin{verbatim}
-    #StartFloat 500,15
+    #StartFloat 500b, MZV=15
     L F1 =
     	-mzv_(8,1,1,5)
     	+29056868/39414375*mzv_(2)^6*mzv_(3)

doc/manual/prepro.tex

@@ -935,6 +935,18 @@ \section{\#enddo}
 do\index{do loop} loop. See the \#do\index{\#do} instruction.
 
 %--#] enddo : 
+%--#[ endfloat :
+
+\section{\#endfloat}
+\label{preendfloat}
+
+\noindent Syntax:
+
+\#endfloat
+
+\noindent See also startfloat (\ref{prestartfloat}) and chapter~\ref{floatingpoint} on the floating point capacity.
+
+%--#] endfloat : 
 %--#[ endif :
 
 \section{\#endif}
@@ -1960,6 +1972,18 @@ \section{\#sortreallocate}
 \FORM's memory usage as measured by ``resident set size''.
 
 %--#] sortreallocate : 
+%--#[ startfloat :
+
+\section{\#startfloat}
+\label{prestartfloat}
+
+\noindent Syntax:
+
+\#startfloat $<$precision$>$ [,MZV=$<$weight$>$]
+
+\noindent See also endfloat (\ref{preendfloat}) and chapter~\ref{floatingpoint} on the floating point capacity.
+
+%--#]  startfloat : 
 %--#[ switch :
 
 \section{\#switch}

doc/manual/statements.tex

@@ -1478,6 +1478,18 @@ \section{endwhile}
 module. \vspace{10mm}
 
 %--#] endwhile : 
+%--#[ evaluate :
+\section{evaluate}
+\label{substaevaluate}
+
+\noindent \begin{tabular}{ll}
+Type & Executable statement\\
+Syntax & evaluate [$<$function name$>$]; \\ 
+\end{tabular} \vspace{4mm}
+
+\noindent See chapter~\ref{floatingpoint} on the floating point capacity.
+
+%--#] evaluate : 
 %--#[ exit :
 
 \section{exit}
@@ -5832,6 +5844,18 @@ \section{threadbucketsize}
 `ON,setup;' statement (\ref{substaon} and \ref{setup}). \vspace{10mm}
 
 %--#] threadbucketsize : 
+%--#[ tofloat :
+\section{tofloat}
+\label{substatofloat}
+
+\noindent \begin{tabular}{ll}
+Type & Executable statement\\
+Syntax & tofloat;
+\end{tabular} \vspace{4mm}
+
+\noindent See chapter~\ref{floatingpoint} on the floating point capacity.
+
+%--#] tofloat : 
 %--#[ topolynomial :
 
 \section{topolynomial}
@@ -5865,6 +5889,18 @@ \section{topolynomial}
 \vspace{10mm}
 
 %--#] topolynomial : 
+%--#[ torational :
+\section{torational}
+\label{substatorational}
+
+\noindent \begin{tabular}{ll}
+Type & Executable statement\\
+Syntax & torational;
+\end{tabular} \vspace{4mm}
+
+\noindent See chapter~\ref{floatingpoint} on the floating point capacity.
+
+%--#] torational : 
 %--#[ tospectator :
 
 \section{tospectator}

sources/pre.c

@@ -32,6 +32,9 @@
   	#[ Includes :
 */
 #include "form3.h"
+#ifdef WITHFLOAT
+#include "math.h"
+#endif
 
 static UBYTE pushbackchar = 0;
 static int oldmode = 0;
@@ -7691,20 +7694,41 @@ int DoStartFloat(UBYTE *s)
 		error = 1;
 	}
 	while ( *s == ',' || *s == ' ' || *s == '\t' ) s++;
+/*
+	The first parameter is the float precision
+*/
 	if ( *s >= '0' && *s <= '9' ) {
 		x = 0;
 		do {
 			x = 10*x + (*s++-'0');
 		} while ( *s >= '0' && *s <= '9' );
-		AC.tDefaultPrecision = x;
+/*
+		The precision can either be in digits or bits. 
+		AC.DefaultPrecision is always in bits. 
+*/
+		if ( tolower(*s) == 'd' ) { AC.tDefaultPrecision = x*log2(10.0); s++; }
+		else if ( tolower(*s) == 'b' ) { AC.tDefaultPrecision = x; s++; }
+		else goto IllPar;
 		while ( *s == ',' || *s == ' ' || *s == '\t' ) s++;
-		if ( *s >= '0' && *s <= '9' ) {
-			x = 0;
-			do {
-				x = 10*x + (*s++ - '0');
-			} while ( *s >= '0' && *s <= '9' );
-			AC.tMaxWeight = x;
-			while ( *s == ',' || *s == ' ' || *s == '\t' ) s++;
+/*
+		The second parameter is either absent, which implies zero MZV weight, 
+		or of the form MZV = <weight>
+*/
+		if ( tolower(*s) == 'm' && tolower(s[1]) == 'z' && tolower(s[2]) == 'v') {
+			s+=3;
+			while ( *s == ' ' || *s == '\t' ) s++;
+			if ( *s != '=') goto IllPar;
+			s++;
+			while ( *s == ' ' || *s == '\t' ) s++;
+			if ( *s >= '0' && *s <= '9' ) {
+				x = 0;
+				do {
+					x = 10*x + (*s++ - '0');
+				} while ( *s >= '0' && *s <= '9' );
+				AC.tMaxWeight = x;
+				while ( *s == ',' || *s == ' ' || *s == '\t' ) s++;
+			}
+			else goto IllPar;
 		}
 		else {
 			AC.tMaxWeight = 0;