Specs for matching a grammar.

spec/matching/machine/grammar_spec.rb

@@ -0,0 +1,6 @@
+require 'spec/matching/machine/setup'
+require 'spec/matching/shared/grammar'
+
+describe "Grammar#match" do
+  it_should_behave_like :ast_grammar
+end

spec/matching/shared/grammar.rb

@@ -0,0 +1,20 @@
+describe :ast_grammar, :shared => true do
+  before :each do
+    @grammar = Pegarus.grammar
+    @grammar.B = Pegarus.pattern("a") + -Pegarus.pattern(1)
+    @grammar.S = (@grammar.B / Pegarus.pattern("b")) * 1
+    @grammar.start = :S
+  end
+
+  it "returns nil if the grammar does not match" do
+    @grammar.match("cab").should be_nil
+  end
+
+  it "returns the index following the last matched character" do
+    @grammar.match("bab").should == 1
+  end
+
+  it "returns the index past the end of the subject when the full subject matches" do
+    @grammar.match("bbba").should == 4
+  end
+end