--repo: rewrite in bash

Library/Homebrew/cmd/--repository.sh

@@ -0,0 +1,33 @@
+#:  * `--repository`, `--repo` [<tap> ...]
+#:
+#:  Display where Homebrew's git repository is located.
+#:
+#:  If <user>`/`<repo> are provided, display where tap <user>`/`<repo>'s directory is located.
+
+normalize-tap-arg() {
+  local tap="$1"
+  local user_repo=(${tap//\// })
+  if [ ${#user_repo[@]} -eq 2 ]; then
+    if ! [[ "${user_repo[1]}" =~ ^homebrew-.+ ]]; then
+      user_repo[1]="homebrew-${user_repo[1]}"
+    fi
+    echo "${user_repo[0]}/${user_repo[1]}" | tr '[:upper:]' '[:lower:]'
+  fi
+}
+
+homebrew---repository() {
+  # HOMEBREW_REPOSITORY is set by brew.sh
+  # shellcheck disable=SC2154
+  if [ $# -eq 0 ]; then
+    echo "${HOMEBREW_REPOSITORY}"
+  else
+    for tap in "$@"; do
+      tap="$(normalize-tap-arg "${tap}")"
+      if [ -n "${tap}" ]; then
+        echo "${HOMEBREW_REPOSITORY}/Library/Taps/${tap}"
+      else
+        odie "Invalid tap name provided!"
+      fi
+    done
+  fi
+}