[zsh] Move func/ directory to zsh/functions

zsh/functions/update-path

@@ -0,0 +1,147 @@
+# Eryn Wells <eryn@erynwells.me>
+# vim: set ft=zsh:
+
+function _update-path-usage
+{
+    local -r function_name=$1
+
+    local usage_string=$(cat <<EOF
+Usage: $function_name <arguments> [<path>...]
+
+Modify the target path-like variable by adding or removing paths provided as
+positional arguments. Before adding, check that the target path variable doesn't
+already contain the path and that the directory exists.
+
+This function returns the number of paths that were skipped in the input. If all
+paths were processed, it returns 0. It returns 255 if an error occurred while
+processing arguments.
+
+Arguments
+---------
+
+%B-e%b | %B--export%b | %B--no-export%b
+    Export the variable after modification. The default is to export if the
+    variable is modified.
+
+%B-f%b | %B--force%b
+    Unconditionally add the path, even if it doesn't exist.
+
+%B-h%b | %B--help%b
+    Print this message.
+
+%B-p%b | %B--prepend%b
+    Prepend paths to the target path variable, instead of appending. When
+    prepending, directories will be added in reverse order so their precedence
+    is preserved. That is, the first directory in the list will be at the start
+    of the path.
+
+%B-P%b | %B--path%b <path_variable_name>
+    The name of a path-like variable to modify. The default is 'path'.
+
+%B-r%b | %B--remove%b
+    Remove paths instead of adding. -p and -f are ignored when removing
+    directories from the path.
+
+%B-v%b | %B--verbose%b
+    Print extra information while processing directories.
+EOF
+)
+
+    print -P $usage_string
+}
+
+function update-path
+{
+    zmodload zsh/zutil
+
+    local -a o_args o_export o_force o_help o_prepend o_remove o_verbose o_pathvar
+    zparseopts -a o_args -D -E -F - \
+        {e,-export,-no-export}=o_export \
+        {f,-force}=o_force \
+        {h,-help}=o_help \
+        {p,-prepend}=o_prepend \
+        {P,-path}:=o_pathvar \
+        {r,-remove}=o_remove \
+        {v,-verbose}=o_verbose
+
+    local -ri parse_status=$?
+    if (( parse_status )); then
+        _update-path-usage $0
+        return 255
+    fi
+
+    if [[ $#o_help -ne 0 ]]; then
+        _update-path-usage $0
+        return 0
+    fi
+
+    local -r verbose=$#o_verbose
+    local -r path_variable_name=${o_pathvar[-1]:-path}
+
+    if ! typeset -p $path_variable_name &> /dev/null; then
+        print "Invalid path variable: \$$path_variable_name" 1>&2
+        return 255
+    fi
+
+    [[ $verbose -ne 0 ]] && print "Modifying $path_variable_name"
+
+    local -i candidates_skipped=0
+    local did_update_path
+
+    local -a candidates=($@)
+    if [[ $#o_prepend -ne 0 ]]; then
+        # If prepending, reverse the list so paths are added in the right order.
+        candidates=(${(Oa)@})
+    fi
+
+    for candidate in $candidates; do
+        local candidate_index=${${(P)path_variable_name}[(Ie)$candidate]}
+
+        # An empty $o_remove means we're adding to the array.
+        if [[ $#o_remove -eq 0 ]]; then
+            if [[ $candidate_index -ne 0 ]]; then
+                [[ $verbose -ne 0 ]] && print "Skipping $candidate"
+                (( candidates_skipped++ ))
+                continue
+            fi
+
+            if [[ $#force -eq 0 && ! -d "$candidate" ]]; then
+                [[ $verbose -ne 0 ]] && print "$candidate doesn't exist"
+                (( candidates_skipped++ ))
+                continue
+            fi
+
+            did_update_path=yes
+
+            [[ $verbose -ne 0 ]] && print "Adding $candidate"
+            if [[ $#o_prepend -ne 0 ]]; then
+                eval "${path_variable_name}=(${candidate} ${path})"
+            else
+                eval "${path_variable_name}+=${candidate}"
+            fi
+        else
+            if [[ $candidate_index -eq 0 ]]; then
+                [[ $verbose -ne 0 ]] && print "Skipping $candidate"
+                (( candidates_skipped++ ))
+                continue
+            fi
+
+            [[ $verbose -ne 0 ]] && print "Removing $candidate"
+
+            did_update_path=yes
+            eval "${path_variable_name}[${candidate_index}]=()"
+        fi
+    done
+
+    if [[ -n $did_update_path && $o_export[(I)--no-export] -ne 0 ]]; then
+        [[ $verbose -ne 0 ]] && print "Exporting $path_variable_name"
+        export $path_variable_name
+        if [[ "$path_variable_name" == "path" ]]; then
+            rehash
+        fi
+    fi
+
+    return $candidates_skipped
+}
+
+update-path "$@"