zsh/Completion/Core/_prefix

#autoload

# Try to ignore the suffix. A bit like e-o-c-prefix.

[[ -n "$SUFFIX" ]] || return 1

local comp i

zstyle -a ":completion:${curcontext}:" completer comp ||
  comp=( "${(@)_completers[1,_completer_num-1][(R)_prefix(|:*),-1]}" )

if zstyle -t ":completion:${curcontext}:" add-space; then
  ISUFFIX=" $SUFFIX"
else
  ISUFFIX="$SUFFIX"
fi
SUFFIX=''

for i in "$comp[@]"; do
  [[ "$i" != _prefix ]] && "$i" && return 0
done

return 1