-# Allow completions in the middle of a text, i.e. "/usr/bin/<TAB>whatever"
-# completes like "/usr/bin/<TAB>". Useful when adding new options to commands.
-bindkey '^I' expand-or-complete-prefix
-# Try uppercase if the currently typed string doesn't match. This allows
-# typing in lowercase most of the time and completion fixes the case.
-zstyle ':completion:*' matcher-list '' 'm:{a-z}={A-Z}'
-
-# Use ls like colors for completions.
+# Support completions in the middle of a word, without this option zsh jumps
+# to the end of the word before the completion process begins. Is required for
+# the _prefix completer.
+setopt completeinword
+
+zstyle ':completion:::::' completer \
+ _expand _complete _prefix _ignored _approximate
+
+# Match specification to be tried when completing items. Each group ('...') is
+# tried after another if no matches were found, once matches are found no
+# other groups are tried. Thanks to Mikachu in #zsh on Freenode (2012-08-28
+# 18:48 CEST) for explanations.
+#
+# When matching also include the uppercase variant of typed characters
+# ('m:{a-z}={A-Z}'); using '' before this group would try the unmodified match
+# first, but I prefer to get all matches immediately (e.g. if Makefile and
+# makefile exist in the current directory echo m<tab> matches both, with '' it
+# would only match makefile because it found one match). This allows typing in
+# lowercase most of the time and completion fixes the case, which is faster.
+#
+# Don't perform these fixes in _approximate to prevent it from changing the
+# input too much. Thanks to the book "From Bash to Z Shell" page 249.
+zstyle ':completion:*:(^approximate):*' matcher-list 'm:{a-z}={A-Z}'
+
+# Allow one mistake per three characters. Thanks to the book "From Bash to Z
+# Shell" page 248.
+zstyle -e ':completion:*:approximate:*' max-errors \
+ 'reply=( $(( ($#PREFIX + $#SUFFIX) / 3 )) )'
+
+# Expand shell wildcards to all matching files after <Tab>. echo *<Tab>
+# results in a b c if the directory contains the files a, b, c. Thanks to the
+# book "From Bash to Z Shell" page 246.
+zstyle ':completion:*:expand:*' tag-order all-expansions
+# Keep prefixes unexpanded if possible: $HOME/<Tab> doesn't expand $HOME,
+# while $HOME<Tab> does.
+zstyle ':completion:*:expand:*' keep-prefix yes
+
+# When completing multiple path components display all matching ambiguous
+# components. For example /u/s/d/r/README<Tab> lists all matching READMEs
+# instead of just the matching paths up to the r/ component. Can be slow if
+# there are many matching files.
+zstyle ':completion:*' list-suffixes yes
+
+# Use ls-like colors for completions.