36735: add ~/.zcalcrc handling to zcalc

ChangeLog

@@ -1,5 +1,7 @@
 2015-10-01  Peter Stephenson  <p.stephenson@samsung.com>
 
+	* 36735: Doc/Zsh/contrib.yo, Functions/Misc/zcalc: ~/.zcalcrc.
+
 	* Andrew Janke: 36729: MACHINES, NEWS, README: fix some typos.
 
 	* 36722: Completion/Unix/Command/_git: allow range to complete

Doc/Zsh/contrib.yo

@@ -3657,6 +3657,14 @@ integer arithmetic, which is not how an ordinary desk calculator
 operates.  To force floating point operation, pass the option tt(-f);
 see further notes below.
 
+If the file tt(~/.zcalcrc) exists it will be sourced inside the function
+once it is set up and about to process the command line.  This
+can be used, for example, to set shell options; tt(emulate -L zsh)
+and tt(setopt extendedglob) are in effect at this point.  Any
+failure to source the file if it exists is treated as fatal.
+As with other initialisation files, the directory tt($ZDOTDIR) is used
+instead of tt($HOME) if it is set.
+
 The mathematical library tt(zsh/mathfunc) will be loaded if it is
 available; see
 ifzman(the section `The zsh/mathfunc Module' in zmanref(zshmodules))\

Functions/Misc/zcalc

@@ -120,6 +120,10 @@ autoload -Uz zmathfuncdef
 float PI E
 (( PI = 4 * atan(1), E = exp(1) ))
 
+if [[ -f "${ZDOTDIR:-$HOME}/.zcalcrc" ]]; then
+  . "${ZDOTDIR:-$HOME}/.zcalcrc" || return 1
+fi
+
 # Process command line
 while [[ -n $1 && $1 = -(|[#-]*|f|e) ]]; do
   optlist=${1[2,-1]}