antlr: Add PackageSize recognition.

src/ElectroGrammar.g4

@@ -3,20 +3,10 @@
  */
 
 grammar ElectroGrammar;
-import Alphabet;
+import PackageSize, Units;
 
-electro_grammar : capacitance;
+electro_grammar : capacitor;
 
-capacitance : NUMBER CPREFIX FARAD?;
-
-fragment DIGIT: [0-9];
-NUMBER: DIGIT* '.'? DIGIT+ | DIGIT+ '.'? DIGIT*;
-
-fragment NANO: 'n' | N A N O;
-fragment PICO: 'p' | P I C O;
-fragment MICRO: 'u' | M I C R O;
-CPREFIX: MICRO | NANO | PICO;
-
-FARAD: F | F A R A D;
+capacitor : capacitance package_size?;
 
 WHITESPACE : [\p{White_Space}] -> skip;

src/PackageSize.g4

@@ -0,0 +1,33 @@
+grammar PackageSize;
+import Alphabet;
+
+package_size: IMPERIAL_SIZE | METRIC_SIZE;
+
+IMPERIAL_SIZE: '01005'
+             | '0201'
+             | '0805'
+             | '1008'
+             | '1206'
+             | '1806'
+             | '2010'
+             | '2512'
+             | IMPERIAL AMBIGUOUS_SIZE
+             | AMBIGUOUS_SIZE IMPERIAL;
+
+METRIC_SIZE : '1005'
+            | '1608'
+            | '2012'
+            | '2520'
+            | '3216'
+            | '3225'
+            | '4516'
+            | '5025'
+            | '6332'
+            | METRIC AMBIGUOUS_SIZE
+            | AMBIGUOUS_SIZE METRIC;
+
+AMBIGUOUS_SIZE : '0402'
+               | '0603';
+
+METRIC   : M | M E T R I C;
+IMPERIAL : I | I M P E R I A L;

src/Units.g4

@@ -0,0 +1,14 @@
+grammar Units;
+import Alphabet;
+
+capacitance: NUMBER CPREFIX FARAD?;
+
+fragment DIGIT: [0-9];
+NUMBER: DIGIT* '.'? DIGIT+ | DIGIT+ '.'? DIGIT*;
+
+fragment NANO: 'n' | N A N O;
+fragment PICO: 'p' | P I C O;
+fragment MICRO: 'u' | M I C R O;
+CPREFIX: MICRO | NANO | PICO;
+
+FARAD: F | F A R A D;