PATCH: Make zcalc understand continuation lines

[Peter Stephenson <p.stephenson@xxxxxxxxxxx>]

diff --git a/Doc/Zsh/contrib.yo b/Doc/Zsh/contrib.yo
index 14886d6..22202b0 100644
--- a/Doc/Zsh/contrib.yo
+++ b/Doc/Zsh/contrib.yo
@@ -3144,7 +3144,12 @@ line preceded by `tt(4> )' is available as tt($4).  The last value
 calculated is available as tt(ans).  Full command line editing, including
 the history of previous calculations, is available; the history is saved in
 the file tt(~/.zcalc_history).  To exit, enter a blank line or type `tt(:q)'
-on its own (`tt(q)' is allowed for historical compatibility).
+on its own (`tt(q)' is allowed for historical compatibility).  A
+line ending with a single backslash is treated in the same fashion
+as it is in command line editing:  the backslash is removed, the
+function prompts for more input (the prompt is preceded by `tt(...)'
+to indicate this), and the lines are combined into one to get the final
+result.
 
 If arguments are given to tt(zcalc) on start up, they are used to prime the
 first few positional parameters.  A visual indication of this is given when
diff --git a/Functions/Misc/zcalc b/Functions/Misc/zcalc
index 3d44f20..2eeb498 100644
--- a/Functions/Misc/zcalc
+++ b/Functions/Misc/zcalc
@@ -155,7 +155,16 @@ for (( num = 1; num <= $#; num++ )); do
 done
 
 psvar[1]=$num
-while vared -cehp "${ZCALCPROMPT}" line; do
+local prev_line cont_prompt
+while vared -cehp "${cont_prompt}${ZCALCPROMPT}" line; do
+  if [[ $line = (|*[^\\])('\\')#'\' ]]; then
+    prev_line+=$line[1,-2]
+    cont_prompt="..."
+    line=
+    continue
+  fi
+  line="$prev_line$line"
+  cont_prompt=
   [[ -z $line ]] && break
   # special cases
   # Set default base if `[#16]' or `[##16]' etc. on its own.


-- 
Peter Stephenson <p.stephenson@xxxxxxxxxxx>       Consultant, Software
Tel: +44 (0)1223 434724              Samsung Cambridge Solution Centre
St John's House, St John's Innovation Park,
Cowley Road, Cambridge, CB4 0DS, UK