Add arithmetic operators to AST

This changeset adds +,-,/,*,<< and >> computation and
AST parse nodes.

2 files changed, 64 insertions, 0 deletions

diff --git a/lib/puppet/parser/ast/arithmetic_operator.rb b/lib/puppet/parser/ast/arithmetic_operator.rb
new file mode 100644
index 000000000..8d9cef86a
--- /dev/null
+++ b/lib/puppet/parser/ast/arithmetic_operator.rb
@@ -0,0 +1,41 @@
+require 'puppet'
+require 'puppet/parser/ast/branch'
+
+class Puppet::Parser::AST
+    class ArithmeticOperator < AST::Branch
+
+        attr_accessor :operator, :lval, :rval
+
+        # Iterate across all of our children.
+        def each
+            [@lval,@rval,@operator].each { |child| yield child }
+        end
+
+        # Returns a boolean which is the result of the boolean operation
+        # of lval and rval operands
+        def evaluate(scope)
+            # evaluate the operands, should return a boolean value
+            lval = @lval.safeevaluate(scope)
+            lval = Puppet::Parser::Scope.number?(lval)
+            if lval == nil
+                raise ArgumentError, "left operand of %s is not a number" % @operator
+            end
+            rval = @rval.safeevaluate(scope)
+            rval = Puppet::Parser::Scope.number?(rval)
+            if rval == nil
+                raise ArgumentError, "right operand of %s is not a number" % @operator
+            end
+
+            # compute result
+            lval.send(@operator, rval)
+        end
+
+        def initialize(hash)
+            super
+
+            unless %w{+ - * / << >>}.include?(@operator)
+                raise ArgumentError, "Invalid arithmetic operator %s" % @operator
+            end
+        end
+    end
+end
diff --git a/lib/puppet/parser/ast/minus.rb b/lib/puppet/parser/ast/minus.rb
new file mode 100644
index 000000000..b0779a8ee
--- /dev/null
+++ b/lib/puppet/parser/ast/minus.rb
@@ -0,0 +1,23 @@
+require 'puppet'
+require 'puppet/parser/ast/branch'
+
+# An object that returns a boolean which is the boolean not
+# of the given value.
+class Puppet::Parser::AST
+    class Minus < AST::Branch
+        attr_accessor :value
+
+        def each
+            yield @value
+        end
+
+        def evaluate(scope)
+            val = @value.safeevaluate(scope)
+            val = Puppet::Parser::Scope.number?(val)
+            if val == nil
+                raise ArgumentError, "minus operand %s is not a number" % val
+            end
+            return -val
+        end
+    end
+end