Create ExprSyntactic.g4

ExprSyntactic.g4

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+parser grammar ExprSyntactic;
+
+options {
+    tokenVocab=ExprLexer;
+}
+
+identifier: IDENTIFIER;
+
+qualifiedIdentifier: identifier {'.' identifier};
+
+literal:  IntegerLiteral
+         | FloatingPointLiteral
+         | CharacterLiteral
+         | StringLiteral
+         | BooleanLiteral
+         | NullLiteral;
+
+expression: expression1 [assignmentOperator expression1];
+
+assignmentOperator: Assignment
+                  | AddAssign
+                  | SubtractAssign
+                  | MultiplyAssign
+                  | DivideAssign
+                  | BitwiseANDAssign
+                  | BitwiseORAssign
+                  | BitwiseXORAssign
+                  | RemainderAssign
+                  | LeftShiftAssign
+                  | SighnedRightShiftAssign
+                  | UnsighnedRightShiftAssign;
+
+type: identifier {'.' identifier} bracketsOpt
+     | basicType;
+
+statementExpression: expression;
+
+constantExpression: expression;
+
+expression1: expression2 [expression1Rest];
+
+expression1Rest: ['?' expression ':' expression1];
+
+expression2: expression3 [expression2Rest];