260 Unicode support with PIC N notation

- Add support for PIC N(num) notation, where field size is num * 2
- Adapted tests to include PIC N

Author: schaloner-kbc

cobol-parser/src/main/scala/za/co/absa/cobrix/cobol/parser/antlr/ParserVisitor.scala

@@ -64,7 +64,7 @@ class ParserVisitor(enc: Encoding,
     s"((?:$char\\(\\d+\\)|$char)$question)"
   }
 
-  val lengthRegex: Regex = "([9XPZA])\\((\\d+)\\)|([9XPZA])".r
+  val lengthRegex: Regex = "([9XNPZA])\\((\\d+)\\)|([9XNPZA])".r
   val numericSPicRegexScaled: Regex = ("(S?)"
                                        + genericLengthRegex('9')
                                        + genericLengthRegex('P', optional = true)
@@ -576,6 +576,9 @@ class ParserVisitor(enc: Encoding,
     else if (ctx.alphaA() != null) {
       visitAlphaA(ctx.alphaA())
     }
+    else if (ctx.alphaN() != null) {
+      visitAlphaN(ctx.alphaN())
+    }
     else if (ctx.COMP_1() != null || ctx.COMP_2() != null) {
       PicExpr(
         Decimal(
@@ -608,6 +611,12 @@ class ParserVisitor(enc: Encoding,
     PicExpr(AlphaNumeric(s"$char($len)", len, None, Some(enc), Some(ctx.getText)))
   }
 
+  override def visitAlphaN(ctx: copybookParser.AlphaNContext): PicExpr = {
+    val text = ctx.getText
+    val (char, len) = length(text)
+    PicExpr(AlphaNumeric(s"$char($len)", len * 2, None, Some(enc), Some(ctx.getText)))
+  }
+
   override def visitAlphaA(ctx: copybookParser.AlphaAContext): PicExpr = {
     val text = ctx.getText
     val (char, len) = length(text)

cobol-parser/src/main/scala/za/co/absa/cobrix/cobol/parser/antlr/copybookLexer.g4

@@ -118,6 +118,7 @@ NINES: '9'+;
 A_S: A+;
 P_S: P+ '9'*;
 X_S: X+;
+N_S: N+;
 S_S: S '9'+ V? P* '9'* | S '9'* V? P* '9'+;
 Z_S: Z+ '9'* P* | Z+ '9'* V P* '9'*;
 V_S: V+ '9'+;
@@ -174,6 +175,14 @@ LENGTH_TYPE_X_1:
     | X+
     ;
 
+LENGTH_TYPE_N:
+    LENGTH_TYPE_N_1+
+    ;
+
+LENGTH_TYPE_N_1:
+      (N LPARENCHAR POSITIVELITERAL RPARENCHAR)
+    | N+
+    ;
 
 LENGTH_TYPE_Z:
     LENGTH_TYPE_Z_1+;
@@ -190,6 +199,8 @@ STRINGLITERAL: QUOTEDLITERAL | HEXNUMBER;
 fragment HEXNUMBER :
 	X '"' [0-9A-F]+ '"'
 	| X '\'' [0-9A-F]+ '\''
+	| N '"' [0-9A-F]+ '"'
+	| N '\'' [0-9A-F]+ '\''
 ;
 
 fragment QUOTEDLITERAL :

cobol-parser/src/main/scala/za/co/absa/cobrix/cobol/parser/antlr/copybookLexer.java

@@ -48,7 +48,7 @@ booleanLiteral
    ;
 
 identifier:
-      IDENTIFIER | THRU_OR_THROUGH | A_S | P_S | P_NS | X_S | S_S | S_NS | Z_S | Z_NS | V_S | V_NS
+      IDENTIFIER | THRU_OR_THROUGH | A_S | P_S | P_NS | X_S | | N_S | S_S | S_NS | Z_S | Z_NS | V_S | V_NS
     | SINGLE_QUOTED_IDENTIFIER // is this valid?
     ;
 
@@ -178,6 +178,11 @@ alphaX:
     | LENGTH_TYPE_X
     ;
 
+alphaN:
+      N_S
+    | LENGTH_TYPE_N
+    ;
+
 alphaA:
       A_S
     | LENGTH_TYPE_A
@@ -192,6 +197,7 @@ pic:
     (
       alphaX
     | alphaA
+    | alphaN
     | (
         signPrecision9 usage?
       | usage? signPrecision9