Updated koans from new regex section.
authorJim Weirich <jim.weirich@gmail.com>
Sun, 22 Aug 2010 06:03:17 +0000 (02:03 -0400)
committerJim Weirich <jim.weirich@gmail.com>
Sun, 22 Aug 2010 06:03:17 +0000 (02:03 -0400)
koans/about_regular_expressions.rb

index 417cca5..941b5e6 100644 (file)
@@ -1,34 +1,35 @@
+# -*- coding: utf-8 -*-
 require File.expand_path(File.dirname(__FILE__) + '/edgecase')
 
 class AboutRegularExpressions < EdgeCase::Koan
   def test_a_pattern_is_a_regular_expression
     assert_equal Regexp, /pattern/.class
   end
-  
+
   def test_a_regexp_can_search_a_string_for_matching_content
     assert_equal "match", "some matching content"[/match/]
   end
-  
+
   def test_a_failed_match_returns_nil
     assert_equal __, "some matching content"[/missing/]
   end
 
   # ------------------------------------------------------------------
-  
+
   def test_question_mark_means_optional
     assert_equal __, "abbcccddddeeeee"[/ab?/]
     assert_equal __, "abbcccddddeeeee"[/az?/]
   end
-  
+
   def test_plus_means_one_or_more
     assert_equal __, "abbcccddddeeeee"[/bc+/]
   end
-  
+
   def test_asterisk_means_zero_or_more
     assert_equal __, "abbcccddddeeeee"[/ab*/]
     assert_equal __, "abbcccddddeeeee"[/az*/]
     assert_equal __, "abbcccddddeeeee"[/z*/]
-    
+
     # THINK ABOUT IT:
     #
     # When would * fail to match?
@@ -36,101 +37,101 @@ class AboutRegularExpressions < EdgeCase::Koan
 
   # THINK ABOUT IT:
   #
-  # We say that the repition operators above are "greedy."
-  # 
+  # We say that the repetition operators above are "greedy."
+  #
   # Why?
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_the_left_most_match_wins
     assert_equal __, "abbccc az"[/az*/]
   end
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_character_classes_give_options_for_a_character
     animals = ["cat", "bat", "rat", "zat"]
     assert_equal __, animals.select { |a| a[/[cbr]at/] }
   end
-  
+
   def test_slash_d_is_a_shortcut_for_a_digit_character_class
     assert_equal __, "the number is 42"[/[0123456789]+/]
     assert_equal __, "the number is 42"[/\d+/]
   end
-  
+
   def test_character_classes_can_include_ranges
     assert_equal __, "the number is 42"[/[0-9]+/]
   end
-  
+
   def test_slash_s_is_a_shortcut_for_a_whitespace_character_class
     assert_equal __, "space: \t\n"[/\s+/]
   end
-  
+
   def test_slash_w_is_a_shortcut_for_a_word_character_class
     # NOTE:  This is more like how a programmer might define a word.
     assert_equal __, "variable_1 = 42"[/[a-zA-Z0-9_]+/]
     assert_equal __, "variable_1 = 42"[/\w+/]
   end
-  
+
   def test_period_is_a_shortcut_for_any_non_newline_character
     assert_equal __, "abc\n123"[/a.+/]
   end
-  
+
   def test_a_character_class_can_be_negated
     assert_equal __, "the number is 42"[/[^0-9]+/]
   end
-  
+
   def test_shortcut_character_classes_are_negated_with_capitals
     assert_equal __, "the number is 42"[/\D+/]
     assert_equal __, "space: \t\n"[/\S+/]
     assert_equal __, "variable_1 = 42"[/\W+/]
   end
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_slash_a_anchors_to_the_start_of_the_string
     assert_equal __, "start end"[/\Astart/]
     assert_equal __, "start end"[/\Aend/]
   end
-  
+
   def test_slash_z_anchors_to_the_end_of_the_string
     assert_equal __, "start end"[/end\z/]
     assert_equal __, "start end"[/start\z/]
   end
-  
+
   def test_caret_anchors_to_the_start_of_lines
     assert_equal __, "num 42\n2 lines"[/^\d+/]
   end
-  
+
   def test_dollar_sign_anchors_to_the_end_of_lines
     assert_equal __, "2 lines\nnum 42"[/\d+$/]
   end
-  
+
   def test_slash_b_anchors_to_a_word_boundary
     assert_equal __, "bovine vines"[/\bvine./]
   end
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_parentheses_group_contents
     assert_equal __, "ahahaha"[/(ha)+/]
   end
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_parentheses_also_capture_matched_content_by_number
     assert_equal __, "Gray, James"[/(\w+), (\w+)/, 1]
     assert_equal __, "Gray, James"[/(\w+), (\w+)/, 2]
   end
-  
+
   def test_variables_can_also_be_used_to_access_captures
     assert_equal __, "Name:  Gray, James"[/(\w+), (\w+)/]
     assert_equal __, $1
     assert_equal __, $2
   end
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_a_vertical_pipe_means_or
     grays = /(James|Dana|Summer) Gray/
     assert_equal __, "James Gray"[grays]
@@ -141,17 +142,17 @@ class AboutRegularExpressions < EdgeCase::Koan
   # THINK ABOUT IT:
   #
   # Explain the difference between a character class ([…]) and alternation (|).
-  
+
   # ------------------------------------------------------------------
-  
+
   def test_scan_is_like_find_all
     assert_equal __, "one two-three".scan(/\w+/)
   end
-  
+
   def test_sub_is_like_find_and_replace
     assert_equal __, "one two-three".sub(/(t\w*)/) { $1[0, 1] }
   end
-  
+
   def test_gsub_is_like_find_and_replace_all
     assert_equal __, "one two-three".gsub(/(t\w*)/) { $1[0, 1] }
   end