More command-line parsing code

README.md

@@ -27,6 +27,10 @@ kgrader uses rake as its command-line interface.
 
 ### Setup
 
+To show all known classes, semesters, and assignments:
+
+    rake list
+
 To load a roster for a course semester:
 
     rake roster cs123 sp2016 myroster.csv
@@ -43,10 +47,6 @@ After verifying that everything looks good, push the grade reports with:
 
 ### Housekeeping
 
-To show all known classes, semesters, and assignments:
-
-    rake list
-
 To do some basic cleanup (i.e., trash uncommitted grading attempts, or reset
 messy internal state after a bad run):
 
@@ -63,7 +63,7 @@ but also delete checked-out student repos and roster files -- dangerous!):
 
 To specify the semester, instead of the inferred current one:
 
-    rake grade cs123 mp1 semester=sp2016
+    rake grade cs123 mp1 semester=sp16
 
 To set a cutoff date after which commits will be ignored:
 

lib/kgrader.rb

@@ -1 +1,2 @@
 require_relative 'kgrader/cli'
+require_relative 'kgrader/util'

lib/kgrader/cli.rb

@@ -5,6 +5,43 @@ module KGrader
       @dir = dir
     end
 
+    def list
+      # TODO
+      puts "[list]"
+    end
+
+    def roster(course, semester, rosterfile)
+      # TODO
+      puts "[installing roster: c=#{course} s=#{semester} rf=#{rosterfile}]"
+    end
+
+    def grade(course, semester, assignment, options = {})
+      # TODO
+      puts "[grading c=#{course} s=#{semester} a=#{assignment}]"
+      puts "  - [students=#{options[:students].inspect}]"
+      puts "  - [due=#{options[:due].inspect}]"
+      puts "  - [fetch=#{options.fetch(:fetch, true).inspect}]"
+      puts "  - [regrade=#{options.fetch(:regrade, false).inspect}]"
+    end
+
+    def commit(course, semester, assignment, options = {})
+      # TODO
+      puts "[committing c=#{course} s=#{semester} a=#{assignment}]"
+      puts "  - [students=#{options[:students].inspect}]"
+    end
+
+    def clean
+      # TODO: also purge uncommitted grades
+      reset_jail
+    end
+
+    def clobber
+      # TODO: confirm
+      reset_jail
+      reset_desk
+    end
+
+    private
     def reset_jail
       jail_dir = File.join(@dir, 'jail')
       FileUtils.rm_rf jail_dir

lib/kgrader/util.rb

@@ -0,0 +1,32 @@
+require 'date'
+
+module KGrader
+  def self.parse_args(raw, num, keywords)
+    args = []
+    options = {}
+
+    raw.each do |arg|
+      if arg.include? '='
+        key, val = arg.split('=', 2)
+        key = key.to_sym
+        yield "unknown keyword #{key}" unless keywords.include? key
+        options[key] = case keywords[key]
+        when :string
+          val
+        when :bool
+          %w(true yes 1 t y).include? val.downcase
+        when :array
+          val.split(",").map! { |x| x.strip.downcase }
+        when :datetime
+          DateTime.parse(val)
+        end
+      else
+        args << arg
+      end
+    end
+
+    yield "too few arguments" if args.size < num
+    yield "too many arguments" if args.size > num
+    return args, options
+  end
+end

rakefile

@@ -1,50 +1,56 @@
 require_relative 'lib/kgrader'
 
-def get_cli
+def cli
   KGrader::CLI.new Rake.application.original_dir
 end
 
-task :clean do
-  cli = get_cli
-  # TODO: also purge uncommitted grades
-  cli.reset_jail
+def parse_args(num, keywords)
+  args, options = KGrader::parse_args ARGV.drop(1), num, keywords do |err|
+    abort err
+  end
+  args.each { |arg| task arg.to_sym {} }
+  args + [options]
 end
 
-task :clobber do
-  cli = get_cli
-  # TODO: confirm
-  cli.reset_jail
-  cli.reset_desk
+task :default => :help do ; end
+
+task :help do
+  puts %{usage:
+- rake list
+- rake roster <course> <semester> <rosterfile>
+- rake grade  <course> <assignment> [semester=<...>] [students=<...>]
+              [due=<...>] [fetch=<yes/no>] [regrade=<yes/no>]
+- rake commit <course> <assignment> [semester=<...>] [students=<...>]
+- rake clean
+- rake clobber}
 end
 
 task :list do
-  # TODO
-  puts '[list!]'
+  cli.list
 end
 
 task :roster do
-  # TODO: [course, assignment, rosterfile]
-  puts '[installing roster!]'
+  course, semester, rosterfile = parse_args 3
+  cli.roster course, semester, rosterfile
 end
 
 task :grade do
-  puts ARGV.inspect
-  course = ARGV[1]
-  assignment = ARGV[2]
+  course, assignment, options = parse_args 2,
+    { :semester => :string, :students => :array, :due => :datetime,
+      :fetch => :bool, :regrade => :bool }
+  cli.grade course, options[:semester], assignment, options
+end
 
-  task course.to_sym {}
-  task assignment.to_sym {}
+task :commit do
+  course, assignment, options = parse_args 2,
+    { :semester => :string, :students => :array }
+  cli.commit course, options[:semester], assignment, options
+end
 
-  # TODO
-  puts "Grading #{assignment} for #{course}..."
-  puts "  - semester:"
-  puts "  - due:"
-  puts "  - fetch:"
-  puts "  - students:"
-  puts "  - regrade:"
+task :clean do
+  cli.clean
 end
 
-task :commit do
-  # TODO: [course, assignment], semester=, students=
-  puts '[committing!]'
+task :clobber do
+  cli.clobber
 end

spec/cs241h

@@ -1 +1 @@
-Subproject commit a0a432cb96f38c230355e3e5b12bbf131beb04bd
+Subproject commit 54398ad4a16ac3d9f7344ecf680f4dd167e05818