[Finishes #114336031] Adds support for parsing ratios

lib/unit/lexer.rb

@@ -63,6 +63,9 @@ def _next_token
       when (text = @ss.scan(/[-+]?[0-9]*\.?[0-9]+/i))
          action { [:SCALAR, BigDecimal.new(text, 10)] }
 
+      when (text = @ss.scan(/[:]/i))
+         action { [:COLON, text] }
+
       when (text = @ss.scan(/\b(?:gm|gram)\b/i))
          action { [:MASS_UOM, 'g'] }
 

lib/unit/lexer_definition.rex

@@ -9,9 +9,11 @@ macro
   UNIT_UOM    \b(?:unit|u)\b
   UNITLESS_UOM \b(?:ea)\b
   EQUIVALENCE_UOM \b(?:meq|eq)\b
+  COLON       [:]
 rule
   {BLANK}
   {SCALAR}      { [:SCALAR, BigDecimal.new(text, 10)] }
+  {COLON}       { [:COLON, text] }
 
   #Mass
   \b(?:gm|gram)\b    { [:MASS_UOM, 'g'] }

lib/unit/parser_definition.y

@@ -1,5 +1,5 @@
 class Unit::Parser
-token SCALAR MASS_UOM VOLUME_UOM UNIT_UOM UNITLESS_UOM EQUIVALENCE_UOM PERCENT SLASH
+token SCALAR MASS_UOM VOLUME_UOM UNIT_UOM UNITLESS_UOM EQUIVALENCE_UOM PERCENT SLASH COLON
 rule
   valid_unit:
     concentration |
@@ -16,7 +16,8 @@ rule
     unit |
     unitless |
     equivalence |
-    percent
+    percent |
+    solution
 
   concentration : mass SLASH volume { return Concentration.new(val[0], val[2]) }
   concentration_no_denom_scalar : mass SLASH VOLUME_UOM { return Concentration.new(val[0], Volume.new(1, val[2])) }
@@ -43,6 +44,8 @@ rule
 
   equivalence : SCALAR EQUIVALENCE_UOM { return Equivalence.new(val[0], val[1]) }
 
+  solution : SCALAR COLON SCALAR { return Concentration.new(Mass.new(val[0] * 1000, 'mg'), Volume.new(val[2], 'ml')) }
+
 end
 
 ---- header

test/parser_test.rb

@@ -97,5 +97,15 @@ class ParserTest < Minitest::Test
         assert_equal "mg/ml", conc.uom
       end
     end
+
+    context "solution" do
+      should "parse a normal solution" do
+        conc = Unit.parse("1:1000")
+
+        assert_equal true, conc.concentration?
+        assert_equal 1, conc.scalar
+        assert_equal "mg/ml", conc.uom
+      end
+    end
   end
 end