[Fix #245] Merge trap into helper

modules/helper/functions/add-zsh-trap

@@ -0,0 +1,50 @@
+#
+# Provides for trapping UNIX signals and calling callback functions when a trap
+# is triggered.
+#
+# Authors:
+#   Sorin Ionescu <sorin.ionescu@gmail.com>
+#
+
+# Trap signals were generated with 'kill -l'.
+# DEBUG, EXIT, and ZERR are Zsh signals.
+_trap_signals=(
+  ABRT ALRM BUS CHLD CONT EMT FPE HUP ILL INFO INT IO KILL PIPE PROF QUIT
+  SEGV STOP SYS TERM TRAP TSTP TTIN TTOU URG USR1 USR2 VTALRM WINCH XCPU XFSZ
+  DEBUG EXIT ZERR
+)
+
+# Adds a function name to a list to be called when a trap is triggered.
+function add-zsh-trap {
+  if (( $# < 2 )); then
+    print "usage: $0 type function" >&2
+    return 1
+  fi
+
+  if [[ -z "$_trap_signals[(r)$1]" ]]; then
+    print "$0: unknown signal: $1" >&2
+    return 1
+  fi
+
+  local trap_functions="TRAP${1}_FUNCTIONS"
+  if (( ! ${(P)+trap_functions} )); then
+    typeset -gaU "$trap_functions"
+  fi
+  eval "$trap_functions+="$2""
+
+  if (( ! $+functions[TRAP${1}] )); then
+    eval "
+      function TRAP${1} {
+        for trap_function in \"\$TRAP${1}_FUNCTIONS[@]\"; do
+          if (( \$+functions[\$trap_function] )); then
+            \"\$trap_function\" \"\$1\"
+          fi
+        done
+        return \$(( 128 + \$1 ))
+      }
+    "
+  fi
+}
+
+add-zsh-trap "$@"
+