Add "brew uses --installed"

Passing --installed will limit the list to formulae that you have installed.
Documented this and "brew deps --1" which limits the dependency list to
one level down (direct dependencies).

Library/Contributions/manpages/brew.1.md

@@ -129,12 +129,18 @@ didn't include with OS X.
   * `outdated`:
     Shows formula that have an updated version available.
 
-  * `deps` <formula>:
+  * `deps [--1]` <formula>:
     Shows <formula>'s dependencies.
 
-  * `uses` <formula>:
-    Shows the formulas that specify <formula> as a dependency. The list is not
-    recursive; only one level of dependencies is resolved.
+    If `--1` is passed, only show dependencies one level down, instead of
+    recursing.
+
+  * `uses [--installed]` <formula>:
+    Shows the formulas that specify <formula> as a dependency. The list is
+    not recursive; only one level of dependencies is resolved.
+
+    If `--installed` is passed, the list only shows formulae you have
+    installed.
 
   * `doctor`:
     Checks your system for potential problems.

bin/brew

@@ -258,7 +258,9 @@ begin
   # For each formula given, show which other formulas depend on it.
   # We only go one level up, ie. direct dependencies.
   when 'uses'
-    puts *ARGV.formulae.map{ |f| Formula.all.select{ |ff| ff.deps.include? f.name }.map{|f| f.name} }.flatten.uniq.sort
+    uses = ARGV.formulae.map{ |f| Formula.all.select{ |ff| ff.deps.include? f.name }.map{|f| f.name} }.flatten.uniq
+    uses = uses.select { |f| Formula.factory(f).installed? } if ARGV.include? "--installed"
+    puts *uses.sort
 
   when 'deps'
     require 'formula_installer'

share/man/man1/brew.1

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "BREW" "1" "July 2010" "Homebrew" "brew"
+.TH "BREW" "1" "August 2010" "Homebrew" "brew"
 .
 .SH "NAME"
 \fBbrew\fR \- The missing package manager for OS X
@@ -141,13 +141,19 @@ Removes dead symlinks from the Homebrew prefix\. This is generally not needed\.
 Shows formula that have an updated version available\.
 .
 .TP
-\fBdeps\fR \fIformula\fR
+\fBdeps [\-\-1]\fR \fIformula\fR
 Shows \fIformula\fR\'s dependencies\.
 .
+.IP
+If \fB\-\-1\fR is passed, only show dependencies one level down, instead of recursing\.
+.
 .TP
-\fBuses\fR \fIformula\fR
+\fBuses [\-\-installed]\fR \fIformula\fR
 Shows the formulas that specify \fIformula\fR as a dependency\. The list is not recursive; only one level of dependencies is resolved\.
 .
+.IP
+If \fB\-\-installed\fR is passed, the list only shows formulae you have installed\.
+.
 .TP
 \fBdoctor\fR
 Checks your system for potential problems\.