improve command and completions

completion.bash

@@ -4,41 +4,85 @@ _comp_cmd_goto() {
   local cur prev words cword comp_args
   _comp_initialize -- "$@" || return
 
-  # echo "[$cur] [$prev] [${words[@]}] [$cword] [$comp_args]"
+  # the list of valid options with their argument requirement
+  # it is updated as the command is parsed
+  local -A valid_opts=([-a]=true [-r]=true [-g]=true [-e]=false [-l]=false [-t]=false)
+  # how many positional arguments are expected
+  local -i expected_positional_args=1
+  # optionals and positionals read up to, not including ${cword} (current word index)
+  local -i opt_args=0 positional_args=0
+  # holds an option that requires its argument to be read next
+  local expected_optarg
 
-  local -A opts=([-e]="" [-l]="" [-t]="")
+  local i word
+  for (( i = 1; i < cword; i++ )); do
+    word="${words[${i}]}"
 
-  local i
-  for i in "${!words[@]}"; do
-    [[ ${words[i]} && $i -ne $cword ]] && unset -v "opts[${words[i]}]"
-    case "${words[i]}" in
-      -e)
-        unset -v 'opts[-l]' 'opts[-t]'
-        ;;
-      -l)
-        unset -v 'opts[-e]' 'opts[-t]'
-        ;;
-      -t)
-        unset -v 'opts[-e]' 'opts[-l]'
-        ;;
-    esac
+    if [[ "${word:0:1}" == '-' ]]; then # reading an option
+
+      # any option is invalid if...
+      if \
+        (( positional_args > 0 )) || # a positional parameter has been specified \
+        [[ -n "${expected_optarg}" ]] || # a previous option is expecting an argument \
+        ! [[ -v valid_opts["${word}"] ]] # the option is invalid given the previously provided ones \
+      then
+        return
+      fi
+
+      local arg_required=${valid_opts["${word}"]}
+
+      case "${word:1}" in
+        a|r)
+          unset -v 'valid_opts[-g]' 'valid_opts[-e]' 'valid_opts[-l]' 'valid_opts[-t]'
+          ;;
+        g|e|l|t)
+          valid_opts=()
+          ;;
+        *)
+          return
+          ;;
+      esac
+
+      if ${arg_required}; then
+        expected_optarg="${word}"
+      else
+        expected_optarg=
+      fi
+
+      expected_positional_args=0
+
+      (( opt_args++ ))
+    elif [[ -n "${expected_optarg}" ]]; then
+      expected_optarg=
+    else
+      (( positional_args++ ))
+
+      if (( positional_args > expected_positional_args )); then
+        return
+      fi
+    fi
   done
 
-  if [[ $cur == -* ]]; then
-    _comp_compgen -- -W '"${!opts[@]}"'
+  if [[ "${cur:0:1}" == '-' ]]; then
+    if [[ -z "${expected_optarg}" ]] && (( positional_args == 0 )); then
+      _comp_compgen -- -W '"${!valid_opts[@]}"'
+    fi
     return
   fi
 
-  case $prev in
-    -e)
-      [[ -v 'opts[-e]' ]] && __goto_comp_keys
-      return
-      ;;
-  esac
+  if [[ "${prev:0:1}" == '-' ]]; then
+    case "${prev:1}" in
+      r|g)
+        __goto_comp_keys
+        ;;
+    esac
+    return
+  fi
 
-  # do goto keys only if we did not have -[elt]
-  [[ ${words[*]} == *\ -* ]] || __goto_comp_keys
+  if (( opt_args == 0 && positional_args == 0 )); then
+    __goto_comp_keys
+  fi
 } &&
   complete -F _comp_cmd_goto goto
 
-# ex: filetype=sh
+# ex: filetype=sh