Added truncate_to_first_and_last strategy

Truncate middle directories from the path. How many directories will be
untouched is controlled by POWERLEVEL9K_SHORTER_DIR_LENGTH.

README.md

@@ -377,8 +377,9 @@ Customizations available are:
 |Default|Truncate whole directories from left. How many is defined by `POWERLEVEL9K_SHORTEN_DIR_LENGTH`|
 |`truncate_middle`|Truncates the middle part of a folder. E.g. you are in a folder named `~/MySuperProjects/AwesomeFiles/BoringOffice`, then it will truncated to `~/MyS..cts/Awe..les/BoringOffice`, if `POWERLEVEL9K_SHORTEN_DIR_LENGTH=3` is also set (controls the amount of characters to be left).|
 |`truncate_from_right`|Just leaves the beginning of a folder name untouched. E.g. your folders will be truncated like so: "/ro../Pr../office". How many characters will be untouched is controlled by `POWERLEVEL9K_SHORTEN_DIR_LENGTH`.|
-|`truncate_to_last`|Truncates everything before the last folder in the path.|
 |`truncate_absolute`|Truncates everything exept the last few characters in the path. E.g. if you are in a folder named "~/Projects/powerlevel9k" and you have set `POWERLEVEL9K_SHORTEN_DIR_LENGTH=3`, you will get "..l9k".|
+|`truncate_to_last`|Truncates everything before the last folder in the path.|
+|`truncate_to_first_and_last|Truncate middle directories from the path. How many directories will be untouched is controlled by POWERLEVEL9K_SHORTER_DIR_LENGTH. E.g. if you are in a folder named "~/Projects/powerlevel9k" and you have set `POWERLEVEL9K_SHORTEN_DIR_LENGTH=1`, you will get "~/../powerlevel9k".||
 |`truncate_to_unique`|Parse all parent path components and truncate them to the shortest unique length. If you copy & paste the result to a shell, after hitting `TAB` it should expand to the original path unambiguously.|
 |`truncate_with_package_name`|Search for a `package.json` or `composer.json` and prints the `name` field to abbreviate the directory path. The precedence and/or files could be set by `POWERLEVEL9K_DIR_PACKAGE_FILES=(package.json composer.json)`. If you have [jq](https://stedolan.github.io/jq/) installed, it will dramatically improve the speed of this strategy.|
 |`truncate_with_folder_marker`|Search for a file that is specified by `POWERLEVEL9K_SHORTEN_FOLDER_MARKER` and truncate everything before that (if found, otherwise stop on $HOME and ROOT).|

powerlevel9k.zsh-theme

@@ -728,7 +728,7 @@ prompt_dir() {
   local state_path=$current_path
   # declare all local variables
   local paths directory test_dir test_dir_length trunc_path threshhold
-  # if we are not in "~" or "/", split the paths into an array
+  # if we are not in "~" or "/", split the paths into an array and exclude "~"
   (( ${#current_path} > 1 )) && paths=(${(s:/:)${current_path//"~\/"/}}) || paths=()
   # only run the code if SHORTEN_DIR_LENGTH is set, or we are using the two strategies that don't rely on it.
   if [[ -n "$POWERLEVEL9K_SHORTEN_DIR_LENGTH" || "$POWERLEVEL9K_SHORTEN_STRATEGY" == "truncate_with_folder_marker" || "$POWERLEVEL9K_SHORTEN_STRATEGY" == "truncate_to_last" ]]; then
@@ -745,16 +745,54 @@ prompt_dir() {
         # truncate characters from the right of the path
         current_path=$(truncatePath "$current_path" $POWERLEVEL9K_SHORTEN_DIR_LENGTH $POWERLEVEL9K_SHORTEN_DELIMITER)
       ;;
-      truncate_to_last)
-        # truncate all characters before the current directory
-        current_path=${current_path##*/}
-      ;;
       truncate_absolute)
         # truncate all characters except the last POWERLEVEL9K_SHORTEN_DIR_LENGTH characters
         if [ ${#current_path} -gt $(( $POWERLEVEL9K_SHORTEN_DIR_LENGTH + ${#POWERLEVEL9K_SHORTEN_DELIMITER} )) ]; then
           current_path=$POWERLEVEL9K_SHORTEN_DELIMITER${current_path:(-POWERLEVEL9K_SHORTEN_DIR_LENGTH)}
         fi
       ;;
+      truncate_to_last)
+        # truncate all characters before the current directory
+        current_path=${current_path##*/}
+      ;;
+      truncate_to_first_and_last)
+        if (( ${#current_path} > 1 )) && (( ${POWERLEVEL9K_SHORTEN_DIR_LENGTH} > 0 )); then
+          threshhold=$(( ${POWERLEVEL9K_SHORTEN_DIR_LENGTH} * 2))
+          # if we are in "~", add it back into the paths array
+          [[ $current_path == '~'* ]] && paths=("~" "${paths[@]}")
+          if (( ${#paths} > $threshhold )); then
+            local num=$(( ${#paths} - ${POWERLEVEL9K_SHORTEN_DIR_LENGTH} ))
+            # repace the middle elements
+            for (( i=$POWERLEVEL9K_SHORTEN_DIR_LENGTH; i<$num; i++ )); do
+              paths[$i+1]=$POWERLEVEL9K_SHORTEN_DELIMITER
+            done
+            current_path="${(j:/:)paths}"
+          fi
+        fi
+      ;;
+      truncate_to_unique)
+        # for each parent path component find the shortest unique beginning
+        # characters sequence. Source: https://stackoverflow.com/a/45336078
+        if (( ${#current_path} > 1 )); then # root and home are exceptions and won't have paths
+          local matching
+          local cur_path='/'
+          [[ $current_path != "~"* ]] && trunc_path='/' || trunc_path=''
+          for directory in ${paths[@]}; do
+            test_dir=''
+            for (( i=0; i<${#directory}; i++ )); do
+              test_dir+="${directory:$i:1}"
+              matching=("$cur_path"/"$test_dir"*/)
+              if [[ ${#matching[@]} -eq 1 ]]; then
+                break
+              fi
+            done
+            trunc_path+="$test_dir/"
+            cur_path+="$directory/"
+          done
+          [[ $current_path == "~"* ]] && trunc_path="~/$trunc_path"
+          current_path="${trunc_path: : -1}"
+        fi
+      ;;
       truncate_with_folder_marker)
         if (( ${#paths} > 0 )); then # root and home are exceptions and won't have paths, so skip this
           local last_marked_folder marked_folder
@@ -833,29 +871,6 @@ prompt_dir() {
           current_path="`echo $packageName | tr -d '"'`$subdirectory_path"
         fi
       ;;
-      truncate_to_unique)
-        # for each parent path component find the shortest unique beginning
-        # characters sequence. Source: https://stackoverflow.com/a/45336078
-        if (( ${#current_path} > 1 )); then # root and home are exceptions and won't have paths
-          local matching
-          local cur_path='/'
-          [[ $current_path != "~"* ]] && trunc_path='/' || trunc_path=''
-          for directory in ${paths[@]}; do
-            test_dir=''
-            for (( i=0; i<${#directory}; i++ )); do
-              test_dir+="${directory:$i:1}"
-              matching=("$cur_path"/"$test_dir"*/)
-              if [[ ${#matching[@]} -eq 1 ]]; then
-                break
-              fi
-            done
-            trunc_path+="$test_dir/"
-            cur_path+="$directory/"
-          done
-          [[ $current_path == "~"* ]] && trunc_path="~/$trunc_path"
-          current_path="${trunc_path: : -1}"
-        fi
-      ;;
       *)
         current_path="$(print -P "%$((POWERLEVEL9K_SHORTEN_DIR_LENGTH+1))(c:$POWERLEVEL9K_SHORTEN_DELIMITER/:)%${POWERLEVEL9K_SHORTEN_DIR_LENGTH}c")"
       ;;

test/segments/dir.spec

@@ -90,6 +90,24 @@ function testTruncateToLastWorks() {
   unset POWERLEVEL9K_SHORTEN_STRATEGY
 }
 
+function testTruncateToFirstAndLastWorks() {
+  POWERLEVEL9K_SHORTEN_DIR_LENGTH=2
+  POWERLEVEL9K_SHORTEN_STRATEGY="truncate_to_first_and_last"
+
+  FOLDER=/tmp/powerlevel9k-test/1/12/123/1234/12345/123456/1234567/12345678/123456789
+  mkdir -p $FOLDER
+  cd $FOLDER
+
+  assertEquals "%K{blue} %F{black}/tmp/12/…/12345678/123456789 %k%F{blue}%f " "$(build_left_prompt)"
+
+  cd -
+  rm -fr /tmp/powerlevel9k-test
+
+  unset FOLDER
+  unset POWERLEVEL9K_SHORTEN_DIR_LENGTH
+  unset POWERLEVEL9K_SHORTEN_STRATEGY
+}
+
 function testTruncateAbsoluteWorks() {
   POWERLEVEL9K_SHORTEN_DIR_LENGTH=2
   POWERLEVEL9K_SHORTEN_STRATEGY="truncate_absolute"