From 2a1d51fbaf34204bf9e4e07eeac28ec484285e5a Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sat, 30 Nov 2024 22:37:33 +0100
Subject: [PATCH 1/8] Implemented default values for arrays

---
 .../org/structs4java/Structs4JavaDsl.xtext    | 34 ++++++++++--
 .../Structs4JavaDslFormatter.xtend            |  1 -
 .../generator/StructGenerator.xtend           | 53 +++++++++++++------
 .../generator/Structs4JavaDslGenerator.xtend  |  2 +-
 .../Structs4JavaDslJvmModelInferrer.xtend     |  6 ---
 .../Structs4JavaDslScopeProvider.xtend        |  2 -
 .../validation/Structs4JavaDslValidator.xtend | 10 ++--
 .../src/main/structs/default-values.structs   |  9 ++++
 .../example/tests/DefaultValueTest.java       | 24 +++++++++
 .../structs4java/StructsBatchCompiler.java    | 22 +++++++-
 10 files changed, 125 insertions(+), 38 deletions(-)

diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext b/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
index ba49779..dc1adf8 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
@@ -91,8 +91,7 @@ ComplexTypeMember:
 
 IntegerMember:
 	(comments += SL_COMMENT)*
-	typename=INTEGER_TYPE name=ID 
-	(array=ArrayDimension)?
+	typename=INTEGER_TYPE name=ID
 	(
 		('sizeof' '(' sizeof=[Member] ')')? &
 		('sizeof' '(' sizeofThis?='this' ')')? &
@@ -101,15 +100,33 @@ IntegerMember:
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
 	('=' defaultValue=LONG)?
 	';'
+	|
+	(comments += SL_COMMENT)*
+    typename=INTEGER_TYPE name=ID
+    array=ArrayDimension
+    (
+        ('sizeof' '(' sizeof=[Member] ')')? &
+        ('sizeof' '(' sizeofThis?='this' ')')? &
+        ('countof' '(' countof=[Member] ')')?
+    )
+    ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+    ('=' defaultValues=IntInitializerList)?
+    ';'
 ;
 
 FloatMember:
 	(comments += SL_COMMENT)*
-	typename=FLOAT_TYPE name=ID 
-	(array=ArrayDimension)?
+	typename=FLOAT_TYPE name=ID
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
 	('=' defaultValue=FLOAT)?
 	';'
+	|
+	(comments += SL_COMMENT)*
+    typename=FLOAT_TYPE name=ID
+    array=ArrayDimension
+    ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+    ('=' defaultValues=FloatInitializerList)?
+    ';'
 ;
 
 StringMember:
@@ -128,6 +145,15 @@ ArrayDimension:
 	{ArrayDimension} '[' (dimension=LONG)? ']'
 ;
 
+IntInitializerList:
+    {IntInitializerList}
+    '{' items+=LONG (',' items+=LONG)* '}'
+;
+
+FloatInitializerList:
+    '{' items+=FLOAT (',' items+=FLOAT)* '}'
+;
+
 QualifiedName:
     ID ('.' ID)*
 ;
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
index a0369f0..e8b3439 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
@@ -13,7 +13,6 @@ import org.structs4java.structs4JavaDsl.Member
 import org.structs4java.structs4JavaDsl.StructDeclaration
 import org.structs4java.structs4JavaDsl.Item
 import org.structs4java.structs4JavaDsl.Structs4JavaDslPackage
-import org.eclipse.xtext.formatting2.regionaccess.ILineRegion
 import org.eclipse.xtext.EcoreUtil2
 
 class Structs4JavaDslFormatter extends AbstractFormatter2 {
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
index c50d5c6..b07dabc 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
@@ -15,6 +15,8 @@ import org.structs4java.structs4JavaDsl.EnumDeclaration
 import org.structs4java.structs4JavaDsl.BitfieldMember
 import org.structs4java.structs4JavaDsl.BitfieldEntry
 
+import java.util.stream.Collectors
+
 /**
  * Generates code from your model files on save.
  * 
@@ -558,7 +560,7 @@ class StructGenerator {
 			FloatMember: m.name
 			StringMember: m.name
 			ComplexTypeMember: m.name
-			BitfieldMember: attributeName(m as BitfieldMember)
+			BitfieldMember: attributeName(m)
 			default: "<anonymous>"		
 		}
 	}
@@ -599,7 +601,7 @@ class StructGenerator {
 			IntegerMember: readerMethodForIntegerMember(m)
 			FloatMember: readerMethodForFloatMember(m)
 			StringMember: readerMethodForStringMember(m)
-			BitfieldMember: readerMethodForBitfieldMember(m as BitfieldMember)
+			BitfieldMember: readerMethodForBitfieldMember(m)
 		}
 	}
 	
@@ -608,12 +610,12 @@ class StructGenerator {
 	}
 	
 	def readerMethodForArrayMember(Member m) '''
-	private static java.util.ArrayList<«m.nativeTypeName().native2JavaType().box()»> «m.readerMethodName()»(java.nio.ByteBuffer buf, boolean partialRead«IF findMemberDefiningCountOf(m) != null», long countof«ENDIF») throws java.io.IOException {
+	private static java.util.ArrayList<«m.nativeTypeName().native2JavaType().box()»> «m.readerMethodName()»(java.nio.ByteBuffer buf, boolean partialRead«IF findMemberDefiningCountOf(m) !== null», long countof«ENDIF») throws java.io.IOException {
 		java.util.ArrayList<«m.nativeTypeName().native2JavaType().box()»> lst = new java.util.ArrayList<«m.nativeTypeName().native2JavaType().box()»>();
 
 		try {
 		«IF dimensionOf(m) == 0»
-		«IF findMemberDefiningCountOf(m) != null»
+		«IF findMemberDefiningCountOf(m) !== null»
         for(long i = 0; i < countof; ++i) {
             lst.add(«readerMethodName(m)»«arrayPostfix(m)»(buf, partialRead));
         }
@@ -827,7 +829,7 @@ class StructGenerator {
 				}
 				«ENDIF»
 
-				«IF m.getNullTerminated() == null»
+				«IF m.getNullTerminated() === null»
 				return new String(tmp, 0, (int)sizeof, "«encodingOf(m)»");
 				«ELSE»
 				int terminatingZeros = "\0".getBytes("«encodingOf(m)»").length;
@@ -941,7 +943,7 @@ class StructGenerator {
 		«ENDFOR»
 	'''
 	
-	def hasSizeOfOrCountOfAttribute(Member m) {
+    def hasSizeOfOrCountOfAttribute(Member m) {
 		return m.hasSizeOfAttribute() || m.hasCountOfAttribute()
 	}
 	
@@ -1365,7 +1367,7 @@ class StructGenerator {
 			«IF findMemberDefiningSizeOf(m) === null»
 			buf.put("\0".getBytes("«encodingOf(m)»"));
 			«ELSE»
-			«IF m.getNullTerminated() != null»
+			«IF m.getNullTerminated() !== null»
 			buf.put("\0".getBytes("«encodingOf(m)»"));
 			«ENDIF»
 			«ENDIF»
@@ -1411,7 +1413,7 @@ class StructGenerator {
 	def fields(StructDeclaration struct) '''
 		«FOR m : struct.members»
 		«IF m instanceof BitfieldMember»
-			«field(m as BitfieldMember)»
+			«field(m)»
 		«ELSE»
 			«field(m)»
 		«ENDIF»
@@ -1421,7 +1423,7 @@ class StructGenerator {
 	def getters(StructDeclaration struct) '''
 		«FOR m : struct.members»
 		«IF m instanceof BitfieldMember»
-			«getter(m as BitfieldMember)»
+			«getter(m)»
 		«ELSE»
 			«getter(m)»
 		«ENDIF»
@@ -1431,7 +1433,7 @@ class StructGenerator {
 	def setters(StructDeclaration struct) '''
 		«FOR m : struct.nonTransientMembers()»
 		«IF m instanceof BitfieldMember»
-			«setter(m as BitfieldMember)»
+			«setter(m)»
 		«ELSE»
 			«setter(m)»
 		«ENDIF»
@@ -1509,7 +1511,7 @@ class StructGenerator {
 	    switch (m) {
             ComplexTypeMember: {
                 if(m.type instanceof EnumDeclaration) {
-                    if(m.defaultValue == null) {
+                    if(m.defaultValue === null) {
                         return "null"
                     }
                     return attributeJavaType(m) + "." + m.defaultValue.name
@@ -1525,8 +1527,17 @@ class StructGenerator {
 	def defaultConstruct(Member m) {
 	    if(m.isArray()) {
 
-	        if(doesAttributeJavaTypeMapToByteBuffer(m)) {
-	            return "java.nio.ByteBuffer.wrap(new byte[]{})"
+	        if(m instanceof IntegerMember) {
+	            if(doesAttributeJavaTypeMapToByteBuffer(m)) {
+
+                    if(m.defaultValues === null) {
+                        return "java.nio.ByteBuffer.wrap(new byte[]{})"
+                    }
+
+                    val initList = m.defaultValues.items.join(", ")
+
+                    return "java.nio.ByteBuffer.wrap(new byte[]{" + initList + "})"
+	            }
 	        }
 
 	        if(m instanceof StringMember) {
@@ -1535,6 +1546,17 @@ class StructGenerator {
 
             val nativeType = nativeTypeName(m)
             val javaType = native2JavaType(nativeType)
+
+            if(m instanceof IntegerMember) {
+                if(m.defaultValues !== null) {
+                    return "new java.util.ArrayList<" + box(javaType) + ">(java.util.Arrays.<Long>asList(" + m.defaultValues.items.stream().map(v | v + "L").collect(Collectors.joining(", ")) + "))"
+                }
+            } else if(m instanceof FloatMember) {
+                if(m.defaultValues !== null) {
+                    return "new java.util.ArrayList<" + box(javaType) + ">(java.util.Arrays.<Double>asList(" + m.defaultValues.items.join(', ') + "))"
+                }
+            }
+
 	        return "new java.util.ArrayList<" + box(javaType) + ">()"
 	    }
 
@@ -1552,7 +1574,7 @@ class StructGenerator {
 
         if(m instanceof ComplexTypeMember) {
 	        if(m.type instanceof EnumDeclaration) {
-	            if(m.defaultValue == null) {
+	            if(m.defaultValue === null) {
 	                return "null"
 	            }
                 return attributeJavaType(m) + "." + m.defaultValue.name
@@ -1582,9 +1604,6 @@ class StructGenerator {
 	}
 
 	def doesAttributeJavaTypeMapToByteBuffer(Member m) {
-	    val nativeType = nativeTypeName(m)
-        val javaType = native2JavaType(nativeType)
-
         if (!isArray(m)) {
             return false
         }
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/Structs4JavaDslGenerator.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/Structs4JavaDslGenerator.xtend
index 3de63ef..0ba1f96 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/Structs4JavaDslGenerator.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/Structs4JavaDslGenerator.xtend
@@ -34,7 +34,7 @@ class Structs4JavaDslGenerator extends AbstractGenerator {
 
 	def javaType(ComplexTypeDeclaration type) {
 		val pkg = type.eContainer as StructsFile
-		if (pkg != null && !pkg.name.empty) {
+		if (pkg !== null && !pkg.name.empty) {
 			return pkg.name + "." + type.name
 		}
 		return type.name
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
index 2bae136..5be17ce 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
@@ -6,7 +6,6 @@ package org.structs4java.jvmmodel
 import com.google.inject.Inject
 import org.eclipse.xtext.xbase.jvmmodel.AbstractModelInferrer
 import org.eclipse.xtext.xbase.jvmmodel.IJvmDeclaredTypeAcceptor
-import org.eclipse.xtext.xbase.jvmmodel.JvmTypesBuilder
 
 /**
  * <p>Infers a JVM model from the source model.</p> 
@@ -16,11 +15,6 @@ import org.eclipse.xtext.xbase.jvmmodel.JvmTypesBuilder
  */
 class Structs4JavaDslJvmModelInferrer extends AbstractModelInferrer {
 
-	/**
-	 * convenience API to build and initialize JVM types and their members.
-	 */
-	@Inject extension JvmTypesBuilder
-
 	/**
 	 * The dispatch method {@code infer} is called for each instance of the
 	 * given element's type that is contained in a resource.
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/scoping/Structs4JavaDslScopeProvider.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/scoping/Structs4JavaDslScopeProvider.xtend
index 2842ba8..bd18509 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/scoping/Structs4JavaDslScopeProvider.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/scoping/Structs4JavaDslScopeProvider.xtend
@@ -5,10 +5,8 @@ package org.structs4java.scoping
 
 import org.eclipse.emf.ecore.EObject
 import org.eclipse.emf.ecore.EReference
-import org.eclipse.xtext.scoping.impl.ImportScope
 import org.structs4java.structs4JavaDsl.Structs4JavaDslPackage
 import org.structs4java.structs4JavaDsl.StructDeclaration
-import org.eclipse.xtext.scoping.Scopes
 
 /**
  * This class contains custom scoping description.
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
index a40b7c7..575771a 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
@@ -19,7 +19,7 @@ class Structs4JavaDslValidator extends AbstractStructs4JavaDslValidator {
 	
 	@Check
 	def checkArrayDimension(Member m) {
-		if(m.array == null) {
+		if(m.array === null) {
 			return;
 		}
 		
@@ -40,11 +40,11 @@ class Structs4JavaDslValidator extends AbstractStructs4JavaDslValidator {
 			}
 			
 		} else {
-			if(getCountOfFor(m) != null) {
+			if(getCountOfFor(m) !== null) {
 				error('Either array dimension or countof must be specified but not both!', m, Structs4JavaDslPackage.Literals.MEMBER__ARRAY)
 			}
 			
-			if(getSizeOfFor(m) != null) {
+			if(getSizeOfFor(m) !== null) {
 				error('Either array dimension or sizeof must be specified but not both!', m, Structs4JavaDslPackage.Literals.MEMBER__ARRAY)
 			}
 		}
@@ -52,7 +52,7 @@ class Structs4JavaDslValidator extends AbstractStructs4JavaDslValidator {
 	
 	@Check
 	def checkArrayDimensionIsBeforeDynamicElement(Member m) {
-		if(m.array == null) {
+		if(m.array === null) {
 			return;
 		}
 		
@@ -87,7 +87,7 @@ class Structs4JavaDslValidator extends AbstractStructs4JavaDslValidator {
 	@Check
 	def disable64BitSizeOfAndCountOf(Member m) {
 		if(m instanceof IntegerMember) {
-			if(m.sizeof != null || m.countof != null || m.sizeofThis) {
+			if(m.sizeof !== null || m.countof !== null || m.sizeofThis) {
 				if(m.typename.equals("uint64_t") || m.typename.equals("int64_t")) {
 					warning('64 bit types for sizeof/countof members are not fully supported!\nThey throw a RuntimeException in case the value is larger than 2^63!', m, Structs4JavaDslPackage.Literals.INTEGER_MEMBER__TYPENAME)
 				}
diff --git a/structs4java-maven-plugin-test/src/main/structs/default-values.structs b/structs4java-maven-plugin-test/src/main/structs/default-values.structs
index d9519cf..8be8b28 100644
--- a/structs4java-maven-plugin-test/src/main/structs/default-values.structs
+++ b/structs4java-maven-plugin-test/src/main/structs/default-values.structs
@@ -16,6 +16,15 @@ struct StructWithStringDefaultValue {
     char str[] = "default";
 }
 
+struct StructWithArrayDefaultValue {
+    uint8_t  int8[3] = { 1, 0x20, 3 };
+    uint16_t int16[3] = { 4, 5, 6 };
+    uint32_t int32[3] = { 7, 8, 9 };
+    uint64_t int64[3] = { 0x10, 0x11, 0x12 };
+    float  f[3] = { 1.0, 2.0, 3.0 };
+    double d[3] = { 4.0, 5.0, 6.0 };
+}
+
 enum Int8Enum : uint8_t {
     A = 0x01,
     B = 0x02,
diff --git a/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/DefaultValueTest.java b/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/DefaultValueTest.java
index c49c93a..3948747 100644
--- a/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/DefaultValueTest.java
+++ b/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/DefaultValueTest.java
@@ -3,6 +3,9 @@
 import org.junit.Test;
 import org.structs4java.example.tests.defaultvalues.*;
 
+import java.nio.ByteBuffer;
+import java.util.List;
+
 import static org.junit.Assert.assertEquals;
 
 public class DefaultValueTest {
@@ -33,4 +36,25 @@ public void testStructWithEnumDefaultValue() {
         StructWithEnum struct = new StructWithEnum();
         assertEquals(Int8Enum.B, struct.getInt8Enum());
     }
+
+    @Test
+    public void testStructWithArrayDefaultValue() {
+        StructWithArrayDefaultValue struct = new StructWithArrayDefaultValue();
+        assertBufferEquals(struct.getInt8(), 1, 0x20, 3);
+        assertListEquals(struct.getInt16(), 4, 5, 6);
+        assertListEquals(struct.getInt32(), 7, 8, 9);
+        assertListEquals(struct.getInt64(), 0x10, 0x11, 0x12);
+    }
+
+    private void assertBufferEquals(ByteBuffer buffer, int... expected) {
+        for(int value : expected) {
+            assertEquals(value, buffer.get() & 0xFF);
+        }
+    }
+
+    private void assertListEquals(List<Long> items, int... expected) {
+        for(int i = 0; i < expected.length; ++i) {
+            assertEquals(expected[i], items.get(i).longValue());
+        }
+    }
 }
diff --git a/structs4java-maven-plugin/src/main/java/org/structs4java/StructsBatchCompiler.java b/structs4java-maven-plugin/src/main/java/org/structs4java/StructsBatchCompiler.java
index 1218ff1..fb91683 100644
--- a/structs4java-maven-plugin/src/main/java/org/structs4java/StructsBatchCompiler.java
+++ b/structs4java-maven-plugin/src/main/java/org/structs4java/StructsBatchCompiler.java
@@ -453,8 +453,12 @@ private StringBuilder createIssueMessage(Issue issue) {
 		issueBuilder.append(filePath).append(":").append(issue.getLineNumber()).append(" ").append(issue.getMessage()).append("\n");
 
 		String sourceLineWithIssue = readLineFromResource(filePath, issue.getLineNumber());
-		issueBuilder.append(sourceLineWithIssue).append("\n");
-		issueBuilder.append(com.google.common.base.Strings.repeat(" ", issue.getColumn() - 1)).append("^");
+		int numTabsBeforeColStart = countTabsTillColumnStart(sourceLineWithIssue, issue.getColumn());
+		// 1 \t replaced by 4 spaces = 3 additional spaces / tab
+		int spacesIntroducedOnTopByReplacingTabsWithSpaces = 3 * numTabsBeforeColStart;
+
+		issueBuilder.append(replaceTabsWith4Spaces(sourceLineWithIssue)).append("\n");
+		issueBuilder.append(com.google.common.base.Strings.repeat(" ", issue.getColumn() - 1 + spacesIntroducedOnTopByReplacingTabsWithSpaces)).append("^");
 		int colLength = issue.getColumnEnd() - issue.getColumn();
 		if(colLength > 1) {
 			issueBuilder.append(com.google.common.base.Strings.repeat("-", colLength - 1));
@@ -462,6 +466,20 @@ private StringBuilder createIssueMessage(Issue issue) {
 		return issueBuilder;
 	}
 
+	private int countTabsTillColumnStart(String str, int colStart) {
+		int count = 0;
+		for(int i = 0; i < colStart; ++i) {
+			if(str.charAt(i) == '\t') {
+				count++;
+			}
+		}
+		return count;
+	}
+
+	private String replaceTabsWith4Spaces(String str) {
+		return str.replaceAll("\t", "    ");
+	}
+
 	private String readLineFromResource(String filePath, int line) {
 		JavaIoFileSystemAccess fileSystemAccess = javaIoFileSystemAccessProvider.get();
 		// if you don't set the output path before using you end up with below exception

From f7d7ff9166d771276b3e367c74bf3738d732f466 Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sat, 30 Nov 2024 22:48:59 +0100
Subject: [PATCH 2/8] Fixed some compiler warnings

---
 .../structs4java/formatting2/Structs4JavaDslFormatter.xtend | 6 +-----
 .../jvmmodel/Structs4JavaDslJvmModelInferrer.xtend          | 1 -
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
index e8b3439..65df5a7 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/formatting2/Structs4JavaDslFormatter.xtend
@@ -3,10 +3,8 @@
  */
 package org.structs4java.formatting2
 
-import com.google.inject.Inject
 import org.eclipse.xtext.formatting2.AbstractFormatter2
 import org.eclipse.xtext.formatting2.IFormattableDocument
-import org.structs4java.services.Structs4JavaDslGrammarAccess
 import org.structs4java.structs4JavaDsl.EnumDeclaration
 import org.structs4java.structs4JavaDsl.Import
 import org.structs4java.structs4JavaDsl.Member
@@ -17,8 +15,6 @@ import org.eclipse.xtext.EcoreUtil2
 
 class Structs4JavaDslFormatter extends AbstractFormatter2 {
 
-	@Inject extension Structs4JavaDslGrammarAccess
-
 	def dispatch void format(org.structs4java.structs4JavaDsl.StructsFile structsFile,
 		extension IFormattableDocument document) {
 		// TODO: format HiddenRegions around keywords, attributes, cross references, etc. 
@@ -50,7 +46,7 @@ class Structs4JavaDslFormatter extends AbstractFormatter2 {
 	}
 
 	def dispatch void format(Import imp, extension IFormattableDocument document) {
-		if ((imp.eContainer as org.structs4java.structs4JavaDsl.StructsFile).getImports().last == imp) {
+		if ((imp.eContainer as org.structs4java.structs4JavaDsl.StructsFile).getImports().lastOrNull == imp) {
 			imp.regionFor.keyword(";").prepend[noSpace].append[newLines = 2]
 		} else {
 			imp.regionFor.keyword(";").prepend[noSpace].append[newLine]
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
index 5be17ce..06c4c09 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/jvmmodel/Structs4JavaDslJvmModelInferrer.xtend
@@ -3,7 +3,6 @@
  */
 package org.structs4java.jvmmodel
 
-import com.google.inject.Inject
 import org.eclipse.xtext.xbase.jvmmodel.AbstractModelInferrer
 import org.eclipse.xtext.xbase.jvmmodel.IJvmDeclaredTypeAcceptor
 

From 324cc75c26077207f431e05dc3032ce33af1c824 Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 09:28:58 +0100
Subject: [PATCH 3/8] Added additional parser validations to inform user if
 default values do not fit into arrays

---
 README.md                                     |  2 +-
 .../tests/DefaultValuesParsingTest.xtend      | 51 +++++++++++++++
 .../validation/Structs4JavaDslValidator.xtend | 65 +++++++++++++++++++
 3 files changed, 117 insertions(+), 1 deletion(-)
 create mode 100644 org.structs4java.parent/org.structs4java.tests/src/org/structs4java/tests/DefaultValuesParsingTest.xtend

diff --git a/README.md b/README.md
index d3987c9..c5704a5 100644
--- a/README.md
+++ b/README.md
@@ -166,7 +166,7 @@ Variable-sized structures contain at least one array field which dimension is de
 ```C++
 struct BString { // no getSizeOf()
   uint32_t  length   sizeOf(value);
-  char      value[]  encoding("UCS-2") null-terminated;
+  char      value[]  encoding("UTF-16LE") null-terminated;
 }
 ```
 In the given example no explicit dimension of field `value` is provided. Instead the field `length` is marked with the `sizeOf` keyword indicating that it's value will provide the size of the overall array `value` in bytes. You can also use the `countOf` keyword to provide the count of elements an array will contain, e.g.
diff --git a/org.structs4java.parent/org.structs4java.tests/src/org/structs4java/tests/DefaultValuesParsingTest.xtend b/org.structs4java.parent/org.structs4java.tests/src/org/structs4java/tests/DefaultValuesParsingTest.xtend
new file mode 100644
index 0000000..1d56d7a
--- /dev/null
+++ b/org.structs4java.parent/org.structs4java.tests/src/org/structs4java/tests/DefaultValuesParsingTest.xtend
@@ -0,0 +1,51 @@
+package org.structs4java.tests
+
+import com.google.inject.Inject
+import org.eclipse.xtext.testing.InjectWith
+import org.eclipse.xtext.testing.XtextRunner
+import org.eclipse.xtext.testing.util.ParseHelper
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.structs4java.structs4JavaDsl.IntegerMember
+import org.structs4java.structs4JavaDsl.FloatMember
+
+import static org.junit.Assert.assertEquals
+
+@RunWith(XtextRunner)
+@InjectWith(Structs4JavaDslInjectorProvider)
+class DefaultValuesParsingTest {
+
+	@Inject
+	ParseHelper<org.structs4java.structs4JavaDsl.StructsFile> parseHelper
+
+	@Test
+	def void structWithValidPrimitivesWithDefaultValues() {
+		val pkg = parseHelper.parse('''
+			struct S {
+			    int8_t   a = 1;
+			    uint8_t  b = 2;
+			    int16_t  c = 3;
+			    uint16_t d = 4;
+			    int32_t  e = 5;
+			    uint32_t f = 6;
+			    int64_t  g = 7;
+			    uint64_t h = 8;
+			    float    i = 1.0;
+			    double   j = 2.0;
+			}
+		''')
+		val struct = pkg.structs.get(0)
+
+		assertEquals(1L, (struct.members.get(0) as IntegerMember).defaultValue)
+		assertEquals(2L, (struct.members.get(1) as IntegerMember).defaultValue)
+		assertEquals(3L, (struct.members.get(2) as IntegerMember).defaultValue)
+		assertEquals(4L, (struct.members.get(3) as IntegerMember).defaultValue)
+		assertEquals(5L, (struct.members.get(4) as IntegerMember).defaultValue)
+		assertEquals(6L, (struct.members.get(5) as IntegerMember).defaultValue)
+		assertEquals(7L, (struct.members.get(6) as IntegerMember).defaultValue)
+		assertEquals(8L, (struct.members.get(7) as IntegerMember).defaultValue)
+		assertEquals(1.0f, (struct.members.get(8) as FloatMember).defaultValue, 0.001f)
+		assertEquals(2.0f, (struct.members.get(9) as FloatMember).defaultValue, 0.001f)
+	}
+
+}
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
index 575771a..700d00b 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/validation/Structs4JavaDslValidator.xtend
@@ -5,6 +5,7 @@ package org.structs4java.validation
 
 import org.eclipse.xtext.validation.Check
 import org.structs4java.structs4JavaDsl.IntegerMember
+import org.structs4java.structs4JavaDsl.FloatMember
 import org.structs4java.structs4JavaDsl.Member
 import org.structs4java.structs4JavaDsl.StructDeclaration
 import org.structs4java.structs4JavaDsl.Structs4JavaDslPackage
@@ -94,6 +95,70 @@ class Structs4JavaDslValidator extends AbstractStructs4JavaDslValidator {
 			}
 		}
 	}
+
+	@Check
+	def defaultValueInitializerListOfIntMemberDoesNotExceedArrayDimension(IntegerMember m) {
+	    if(m.array === null) {
+	        return
+	    }
+
+	    if(m.array.dimension == 0) {
+	        return
+	    }
+
+	    if(m.defaultValues === null) {
+	        return
+	    }
+
+	    if(m.array.dimension < m.defaultValues.items.size) {
+	        error("Can't fit default values (size=" + m.defaultValues.items.size + ") into fixed-sized array(size=" + m.array.dimension + ").", m, Structs4JavaDslPackage.Literals.INTEGER_MEMBER__DEFAULT_VALUES)
+	    }
+	}
+
+	@Check
+    def defaultValueInitializerListOfIntMemberDoesNotExceedArrayDimension(FloatMember m) {
+        if(m.array === null) {
+            return
+        }
+
+        if(m.array.dimension == 0) {
+            return
+        }
+
+        if(m.defaultValues === null) {
+            return
+        }
+
+        if(m.array.dimension < m.defaultValues.items.size) {
+            error("Can't fit default values (size=" + m.defaultValues.items.size + ") into fixed-sized array(size=" + m.array.dimension + ").", m, Structs4JavaDslPackage.Literals.FLOAT_MEMBER__DEFAULT_VALUES)
+        }
+    }
+
+    @Check
+    def defaultValueInitializerListOfIntMemberDoesNotExceedArrayDimension(StringMember m) {
+        if(m.array === null) {
+            return
+        }
+
+        if(m.array.dimension == 0) {
+            return
+        }
+
+        if(m.defaultValue === null) {
+            return
+        }
+
+        val encoding = if(m.encoding !== null) m.encoding else "UTF-8"
+        var lenBytes = m.defaultValue.getBytes(encoding).length
+
+        if(m.nullTerminated !== null) {
+            lenBytes += "\u0000".getBytes(encoding).length
+        }
+
+        if(m.array.dimension < lenBytes) {
+            error("Can't fit default value (size=" + lenBytes + ") into fixed-sized array(size=" + m.array.dimension + ").", m, Structs4JavaDslPackage.Literals.STRING_MEMBER__DEFAULT_VALUE)
+        }
+    }
 	
 	def getSizeOfFor(Member m) {
 		val struct = m.eContainer as StructDeclaration;

From a3cb9a154e08216fb5f9d7ad54b5740304486fd3 Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 11:47:29 +0100
Subject: [PATCH 4/8] Added support for constants

---
 .../org/structs4java/Structs4JavaDsl.xtext    |   5 +
 .../generator/StructGenerator.xtend           | 113 +++++++++++++--
 .../src/main/structs/constants.structs        |  31 +++++
 .../example/tests/ConstantTest.java           | 129 ++++++++++++++++++
 4 files changed, 265 insertions(+), 13 deletions(-)
 create mode 100644 structs4java-maven-plugin-test/src/main/structs/constants.structs
 create mode 100644 structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/ConstantTest.java

diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext b/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
index dc1adf8..c241f6f 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext
@@ -98,6 +98,7 @@ IntegerMember:
 		('countof' '(' countof=[Member] ')')?
 	)
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+	(constant='const')?
 	('=' defaultValue=LONG)?
 	';'
 	|
@@ -110,6 +111,7 @@ IntegerMember:
         ('countof' '(' countof=[Member] ')')?
     )
     ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+    (constant='const')?
     ('=' defaultValues=IntInitializerList)?
     ';'
 ;
@@ -118,6 +120,7 @@ FloatMember:
 	(comments += SL_COMMENT)*
 	typename=FLOAT_TYPE name=ID
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+	(constant='const')?
 	('=' defaultValue=FLOAT)?
 	';'
 	|
@@ -125,6 +128,7 @@ FloatMember:
     typename=FLOAT_TYPE name=ID
     array=ArrayDimension
     ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+    (constant='const')?
     ('=' defaultValues=FloatInitializerList)?
     ';'
 ;
@@ -137,6 +141,7 @@ StringMember:
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
 	('filler' '(' filler=LONG ')')?
 	(nullTerminated='null-terminated')?
+	(constant='const')?
 	('=' defaultValue=STRING)?
 	';'
 ;
diff --git a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
index b07dabc..247addf 100644
--- a/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
+++ b/org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend
@@ -384,14 +384,27 @@ class StructGenerator {
 							java.nio.ByteBuffer slice = buf.slice();
 							slice.order(buf.order());
 							slice.limit((int)«tempVarForMember(findMemberDefiningSizeOf(m))»);
+							«IF isConst(m)»
+							«readerMethodName(m)»(slice, true);
+							«ELSE»
 							obj.«setterName(m)»(«readerMethodName(m)»(slice, true));
+							«ENDIF»
+
 							buf.position(buf.position() + (int)«tempVarForMember(findMemberDefiningSizeOf(m))»);
 						}
 						«ELSE»
-						obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningSizeOf(m))»));
+						«IF isConst(m)»
+						«readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningSizeOf(m))»);
+                        «ELSE»
+                        obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningSizeOf(m))»));
+                        «ENDIF»
 						«ENDIF»
 					«ELSEIF findMemberDefiningCountOf(m) !== null»
-						obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningCountOf(m))»));
+					    «IF isConst(m)»
+					    «readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningCountOf(m))»);
+                        «ELSE»
+                        obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)«tempVarForMember(findMemberDefiningCountOf(m))»));
+                        «ENDIF»
 					«ELSE»
 						«IF m.isBitfield()»
 							«IF m.isArray()»
@@ -402,9 +415,9 @@ class StructGenerator {
 								long value = «readerMethodName(m)»(buf, partialRead);
 								«FOR entry : (m as BitfieldMember).entries»
 									«IF entry.type !== null»
-									obj.«setterName(entry)»(«javaType(entry.type)».fromValue((value & «computeBitmaskFor(entry)») >>> «computeBitsToShift(entry)»));
+                                    obj.«setterName(entry)»(«javaType(entry.type)».fromValue((value & «computeBitmaskFor(entry)») >>> «computeBitsToShift(entry)»));
 									«ELSEIF entry.typename == "boolean"»
-									obj.«setterName(entry)»(((value & «computeBitmaskFor(entry)») >>> «computeBitsToShift(entry)») != 0);
+                                    obj.«setterName(entry)»(((value & «computeBitmaskFor(entry)») >>> «computeBitsToShift(entry)») != 0);
 									«ELSE»
 									obj.«setterName(entry)»((value & «computeBitmaskFor(entry)») >>> «computeBitsToShift(entry)»);
 									«ENDIF»
@@ -413,13 +426,25 @@ class StructGenerator {
 							«ENDIF»	
 						«ELSEIF m.isArray() && !m.isString() && m.isGreedy()»
 							«IF struct.isSelfSized()»
-							obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)(structEndPosition - buf.position())));
+							«IF isConst(m)»
+							«readerMethodName(m)»(buf, partialRead, (int)(structEndPosition - buf.position()));
+                            «ELSE»
+                            obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)(structEndPosition - buf.position())));
+                            «ENDIF»
 							«ELSE»
 							// greedy member
-							obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)(buf.limit() - buf.position())));
+							«IF isConst(m)»
+							«readerMethodName(m)»(buf, partialRead, (int)(buf.limit() - buf.position()));
+                            «ELSE»
+                            obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead, (int)(buf.limit() - buf.position())));
+                            «ENDIF»
 							«ENDIF»
 						«ELSE»
-							obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead));
+						    «IF isConst(m)»
+						    «readerMethodName(m)»(buf, partialRead);
+                            «ELSE»
+                            obj.«setterName(m)»(«readerMethodName(m)»(buf, partialRead));
+                            «ENDIF»
 						«ENDIF»
 					«ENDIF»
 				«ENDIF»
@@ -608,6 +633,12 @@ class StructGenerator {
 	def getDefiningStruct(Member m) {
 		return m.eContainer as StructDeclaration;
 	}
+
+	def getDefaultValues(Member m) {
+        if(m instanceof IntegerMember) return m.defaultValues.items
+        if(m instanceof FloatMember) return m.defaultValues.items
+        return null
+    }
 	
 	def readerMethodForArrayMember(Member m) '''
 	private static java.util.ArrayList<«m.nativeTypeName().native2JavaType().box()»> «m.readerMethodName()»(java.nio.ByteBuffer buf, boolean partialRead«IF findMemberDefiningCountOf(m) !== null», long countof«ENDIF») throws java.io.IOException {
@@ -635,9 +666,15 @@ class StructGenerator {
 			}
 		}
 
+		«IF isConst(m)»
+		«FOR i : 0 ..< getDefaultValues(m).size»
+		if(lst.get(«i») != «getDefaultValues(m).get(i)») throw new java.io.IOException("Expected constant '«getDefaultValues(m).get(i)»' but got '" + lst.get(«i») + "'.");
+		«ENDFOR»
+		«ENDIF»
+
 		return lst;
 	}
-	
+
 	«readerMethodForPrimitive(m)»
 	'''
 	
@@ -660,6 +697,17 @@ class StructGenerator {
 				buf.position(buf.position() + «m.padding» - bytesOverlap);				
 			}
 			«ENDIF»
+
+			«IF isConst(m)»
+			«FOR i : 0 ..< getDefaultValues(m).size»
+			{
+			    int actual = buffer.get(«i») & 0xFF;
+                if(actual != «getDefaultValues(m).get(i)») throw new java.io.IOException("Expected constant '«getDefaultValues(m).get(i)»' but got '" + actual + "' at offset «i».");
+            }
+            «ENDFOR»
+            buffer.position(0);
+			«ENDIF»
+
 			return buffer; 
 		}
 	'''
@@ -723,6 +771,11 @@ class StructGenerator {
 			buf.position(buf.position() + «m.padding» - 8);
 			«ENDIF»
 			«ENDIF»
+
+			«IF isConst(m) && !m.isArray()»
+            if(value != «m.defaultValue») throw new java.io.IOException("Expected constant '«m.defaultValue»' but got '" + value + "'.");
+            «ENDIF»
+
 			return value;
 		}
 	'''
@@ -787,12 +840,18 @@ class StructGenerator {
 			buf.position(buf.position() + «m.padding» - 8);
 			«ENDIF»
 			«ENDIF»
+
+			«IF isConst(m) && !m.isArray()»
+            if(value != «m.defaultValue») throw new java.io.IOException("Expected constant '«m.defaultValue»' but got '" + value + "'.");
+            «ENDIF»
+
 			return value;
 		}
 	'''
 
 	def readerMethodForStringMember(StringMember m) '''
 		private static String «m.readerMethodName()»(java.nio.ByteBuffer buf, boolean partialRead«IF dimensionOf(m) == 0 && findMemberDefiningSizeOf(m) !== null», «attributeJavaType(findMemberDefiningSizeOrCountOf(m))» sizeof«ENDIF») throws java.io.IOException {
+			String value = null;
 			«IF dimensionOf(m) == 0 && findMemberDefiningSizeOf(m) === null»
 			java.io.ByteArrayOutputStream tmp = new java.io.ByteArrayOutputStream();
 			int zerosRead = 0;
@@ -816,7 +875,7 @@ class StructGenerator {
 					buf.position(buf.position() + «m.padding» - bytesOverlap);				
 				}
 				«ENDIF»
-				return new String(tmp.toByteArray(), 0, tmp.size() - zerosRead, "«encodingOf(m)»");
+				value = new String(tmp.toByteArray(), 0, tmp.size() - zerosRead, "«encodingOf(m)»");
 				«ELSE»
 
 				byte[] tmp = new byte[(int)sizeof];
@@ -830,10 +889,10 @@ class StructGenerator {
 				«ENDIF»
 
 				«IF m.getNullTerminated() === null»
-				return new String(tmp, 0, (int)sizeof, "«encodingOf(m)»");
+				value = new String(tmp, 0, (int)sizeof, "«encodingOf(m)»");
 				«ELSE»
 				int terminatingZeros = "\0".getBytes("«encodingOf(m)»").length;
-				return new String(tmp, 0, (int)(sizeof - terminatingZeros), "«encodingOf(m)»");
+				value = new String(tmp, 0, (int)(sizeof - terminatingZeros), "«encodingOf(m)»");
 				«ENDIF»
 
 				«ENDIF»
@@ -859,7 +918,7 @@ class StructGenerator {
 				«IF m.isPadded() && (dimensionOf(m) % m.padding) > 0»
 				buf.position(buf.position() + «m.padding - (dimensionOf(m) % m.padding)»);
 				«ENDIF»
-				return new String(tmp, 0, len, "«encodingOf(m)»");
+				value = new String(tmp, 0, len, "«encodingOf(m)»");
 			«ENDIF»
 			} catch(java.io.UnsupportedEncodingException e) {
 				throw new java.io.IOException(e);
@@ -869,9 +928,15 @@ class StructGenerator {
 				if(!partialRead) {
 					throw e;
 				}
-				return new String(tmp.toByteArray(), 0, tmp.size() - zerosRead, "«encodingOf(m)»");
+				value = new String(tmp.toByteArray(), 0, tmp.size() - zerosRead, "«encodingOf(m)»");
 			}
 			«ENDIF»
+
+			«IF isConst(m)»
+            if(!"«m.defaultValue»".equals(value)) throw new java.io.IOException("Expected constant '«m.defaultValue»' but got '" + value + "'.");
+            «ENDIF»
+
+			return value;
 		}
 	'''
 	
@@ -1432,14 +1497,36 @@ class StructGenerator {
 
 	def setters(StructDeclaration struct) '''
 		«FOR m : struct.nonTransientMembers()»
+		«IF !isConst(m)»
 		«IF m instanceof BitfieldMember»
 			«setter(m)»
 		«ELSE»
 			«setter(m)»
 		«ENDIF»
+		«ENDIF»
 		«ENDFOR»
 	'''
 
+	def isConst(Member m) {
+	    if(m instanceof ComplexTypeMember) {
+	        return false
+	    }
+
+	    if(m instanceof IntegerMember) {
+	        return m.constant !== null
+	    }
+
+	    if(m instanceof FloatMember) {
+            return m.constant !== null
+        }
+
+        if(m instanceof StringMember) {
+            return m.constant !== null
+        }
+
+        return false
+	}
+
 	def field(Member m) '''
 		«printComments(m)»
 		private «attributeJavaType(m)» «attributeName(m)» = «defaultConstruct(m)»;
diff --git a/structs4java-maven-plugin-test/src/main/structs/constants.structs b/structs4java-maven-plugin-test/src/main/structs/constants.structs
new file mode 100644
index 0000000..7e18029
--- /dev/null
+++ b/structs4java-maven-plugin-test/src/main/structs/constants.structs
@@ -0,0 +1,31 @@
+package org.structs4java.example.tests.constants;
+
+struct StructWithPrimitiveConstants {
+    int8_t   a const = 1;
+    uint8_t  b const = 2;
+    int16_t  c const = 3;
+    uint16_t d const = 4;
+    int32_t  e const = 5;
+    uint32_t f const = 6;
+    int64_t  g const = 7;
+    uint64_t h const = 8;
+    float    i const = 1.0;
+    double   j const = 2.0;
+}
+
+struct StructWithArrayConstants {
+    int8_t   a[1] const = { 1 };
+    uint8_t  b[1] const = { 2 };
+    int16_t  c[1] const = { 3 };
+    uint16_t d[1] const = { 4 };
+    int32_t  e[1] const = { 5 };
+    uint32_t f[1] const = { 6 };
+    int64_t  g[1] const = { 7 };
+    uint64_t h[1] const = { 8 };
+    float    i[1] const = { 1.0 };
+    double   j[1] const = { 2.0 };
+}
+
+struct StructWithStringConstant {
+    char str[4] const = "test";
+}
diff --git a/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/ConstantTest.java b/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/ConstantTest.java
new file mode 100644
index 0000000..5b8f4ff
--- /dev/null
+++ b/structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/ConstantTest.java
@@ -0,0 +1,129 @@
+package org.structs4java.example.tests;
+
+import org.junit.Test;
+import org.structs4java.example.tests.constants.StructWithArrayConstants;
+import org.structs4java.example.tests.constants.StructWithPrimitiveConstants;
+import org.structs4java.example.tests.constants.StructWithStringConstant;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+public class ConstantTest {
+
+    @Test(expected = IOException.class)
+    public void testStructWithPrimitiveConstantsFailsOnIntegerMember() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x00,
+                0x00,
+                0x00, 0x00,
+                0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithPrimitiveConstants.read(buffer);
+    }
+
+    @Test(expected = IOException.class)
+    public void testStructWithPrimitiveConstantsFailsOnFloatMember() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x01,
+                0x02,
+                0x03, 0x00,
+                0x04, 0x00,
+                0x05, 0x00, 0x00, 0x00,
+                0x06, 0x00, 0x00, 0x00,
+                0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, (byte)0x80, 0x3F,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithPrimitiveConstants.read(buffer);
+    }
+
+    @Test(expected = IOException.class)
+    public void testStructWithArrayConstantsFailsOnIntegerMember() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x00,
+                0x00,
+                0x00, 0x00,
+                0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithArrayConstants.read(buffer);
+    }
+
+    @Test(expected = IOException.class)
+    public void testStructWithArrayConstantsFailsOnFloatMember() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x01,
+                0x02,
+                0x03, 0x00,
+                0x04, 0x00,
+                0x05, 0x00, 0x00, 0x00,
+                0x06, 0x00, 0x00, 0x00,
+                0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, (byte)0x80, 0x3F,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithArrayConstants.read(buffer);
+    }
+
+    @Test(expected = IOException.class)
+    public void testStructWithStringConstantFails() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{0x74, 0x61, 0x73, 0x74});
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithStringConstant.read(buffer);
+    }
+
+    @Test
+    public void testStructWithPrimitiveConstantsPasses() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x01,
+                0x02,
+                0x03, 0x00,
+                0x04, 0x00,
+                0x05, 0x00, 0x00, 0x00,
+                0x06, 0x00, 0x00, 0x00,
+                0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, (byte)0x80, 0x3F,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithPrimitiveConstants.read(buffer);
+    }
+
+    @Test
+    public void testStructWithArrayConstantsPasses() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{
+                0x01,
+                0x02,
+                0x03, 0x00,
+                0x04, 0x00,
+                0x05, 0x00, 0x00, 0x00,
+                0x06, 0x00, 0x00, 0x00,
+                0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                0x00, 0x00, (byte)0x80, 0x3F,
+                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40 });
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithArrayConstants.read(buffer);
+    }
+
+    @Test
+    public void testStructWithStringConstantPasses() throws IOException {
+        ByteBuffer buffer = ByteBuffer.wrap(new byte[]{0x74, 0x65, 0x73, 0x74});
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        StructWithStringConstant.read(buffer);
+    }
+}

From 436367f68d7dc70a82b8d6f58a5dbaa0f631b9ad Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 12:13:53 +0100
Subject: [PATCH 5/8] Updated readme and example project to make use of new
 features

---
 README.md                                     | 62 +++++++++++++++++--
 .../src/main/structs/zip.structs              |  6 +-
 .../java/examples/zip/ZipFileWritingTest.java |  3 -
 3 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index c5704a5..aa286ec 100644
--- a/README.md
+++ b/README.md
@@ -120,7 +120,7 @@ fileHeader.write(buffer);
 The following table shows the built-in data types of Structs4Java. They can be used to compose more advanced types.
 
 | S4J Typename  | Java Mapping           | Size (bytes) | Subject to Endianess | Description                            |
-| ------------- | ---------------------- | ------------ | ---------------------| -------------------------------------- |
+| ------------- | ---------------------- | ------------ | ---------------------|----------------------------------------|
 | uint8_t       | long                   | 1            | no                   | Fixed-size 8bit unsigned integer       |
 | int8_t        | long                   | 1            | no                   | Fixed-size 8bit signed integer         |
 | uint16_t      | long                   | 2            | yes                  | Fixed-size 16bit unsigned integer      |
@@ -131,11 +131,16 @@ The following table shows the built-in data types of Structs4Java. They can be u
 | int64_t       | long                   | 8            | yes                  | Fixed-size 64bit signed integer        |
 | float         | double                 | 4            | no                   | Fixed-size 32bit floating point number |
 | double        | double                 | 8            | no                   | Fixed-size 64bit floating point number |
-| char[]        | String                 | variable     | no                   | String of characters (max size 2^31)   |
-| uint8_t[]     | java.nio.ByteBuffer    | variable     | no                   | Raw ByteBuffer                         |
-| int8_t[]      | java.nio.ByteBuffer    | variable     | no                   | Raw ByteBuffer                         |
+| char[]        | String                 | variable     | no                   | String of characters (max size 2^31)<sup>1</sup>   |
+| uint8_t[]     | java.nio.ByteBuffer    | variable     | no                   | Raw ByteBuffer<sup>2</sup>             |
+| int8_t[]      | java.nio.ByteBuffer    | variable     | no                   | Raw ByteBuffer<sup>2</sup>             |
 
-There is no primitive type `char` available. If you need to read a single 1-byte character you can use `char[1]` instead.
+<sup>1</sup> There is no primitive type `char` available. If you need to read a single 1-byte character you can use `char[1]` instead.  
+
+<sup>2</sup> When a field is mapped to a  `java.nio.ByteBuffer`, the underlying buffer stored in the struct is a 
+slice of the original buffer passed into the `read(java.nio.ByteBuffer)` method, and NOT a copy. Hence, the fields' buffer stays only 
+valid until you deallocate the original buffer. This is done for performance reasons to avoid reading potential large amounts of
+unstructured/binary data until it is explicitly requested.
 
 ## Advanced Data Types (Structs & Enums)
 
@@ -429,6 +434,53 @@ enum SomeEnum : uint8_t {
 ```
 You can NOT define default values for fields within a bitfield, though.
 
+Note that default values are only used during default construction of the structures. A default value is NOT returned if the read operation did not yield any value from the underlying buffer, e.g.
+```
+struct SomeStruct {
+  char str[] = "my default";
+}
+```
+
+```Java
+ByteBuffer buffer = ByteBuffer.wrap(new byte[]{});
+SomeStruct struct = SomeStruct.read(buffer);
+
+assertEquals("", struct.getStr());
+```
+
+```Java
+SomeStruct struct = new SomeStruct();
+
+assertEquals("my default", struct.getStr());
+```
+
+You can also assign default values to arrays of primitives, e.g.
+```
+struct SomeStruct {
+  uint8_t  int8[3]  = { 1, 0x02, 3 };
+  uint16_t int16[3] = { 0x45, 2, 3 };
+  uint32_t int32[3] = { 7, 8, 9 };
+  uint64_t int64[3] = { 0x20, 0x21, 0x22 };
+  float    f[3]     = { 7.534, 1.4, 3.2 };
+  double   d[3]     = { 9.75142476, 0.0, 7.7777 }
+}
+```
+
+## Constants
+Constants are fields that have a default value and are marked as `const`, e.g.
+```
+struct SomeStruct {
+  uint8_t magic[4] const = { 0x50, 0x4b, 0x01, 0x02 };
+}
+```
+Once a field is marked as `const` only the corresponding getter method will be generated and you won't be able to 
+override the fields' value. Furthermore, during the read operation of the structure, the value read from the underlying 
+buffer will be compared with the expected default value. If the values don't match, an `java.io.IOException` will be thrown.
+
+Typical use cases for constants are magic or signature fields within structures.
+
+Constants are NOT supported on structures, enums, bitfields or enum fields (unlike default values).
+
 ## Plugin configuration
 
 Below is a full example configuration, including the default values, of the plugin:
diff --git a/examples/zip-file-format/src/main/structs/zip.structs b/examples/zip-file-format/src/main/structs/zip.structs
index 989d444..9672f6e 100644
--- a/examples/zip-file-format/src/main/structs/zip.structs
+++ b/examples/zip-file-format/src/main/structs/zip.structs
@@ -1,7 +1,7 @@
 package examples.zip;
 
 struct LocalFileHeader {
-    uint8_t  signature[4];
+    uint8_t  signature[4] const = { 0x50, 0x4b, 0x03, 0x04 };
     uint16_t version;
     bitfield uint16_t {
         uint16_t generalPurposeFlags : 16;
@@ -25,7 +25,7 @@ struct ExtraFieldRecord {
 }
 
 struct CentralDirectoryFileHeader {
-    uint8_t signature[4];
+    uint8_t signature[4] const = { 0x50, 0x4b, 0x01, 0x02 };
     uint16_t versionMadeBy;
     uint16_t versionNeededToExtract;
     bitfield uint16_t {
@@ -50,7 +50,7 @@ struct CentralDirectoryFileHeader {
 }
 
 struct EndOfCentralDirectoryRecord {
-    uint8_t signature[4];
+    uint8_t signature[4] const = { 0x50, 0x4b, 0x05, 0x06 };
     uint16_t diskNumber;
     uint16_t diskWhereCentralDirectoryStarts;
     uint16_t numberOfCentralDirectoryRecordsOnThisDisk;
diff --git a/examples/zip-file-format/src/test/java/examples/zip/ZipFileWritingTest.java b/examples/zip-file-format/src/test/java/examples/zip/ZipFileWritingTest.java
index af694dd..0169d02 100644
--- a/examples/zip-file-format/src/test/java/examples/zip/ZipFileWritingTest.java
+++ b/examples/zip-file-format/src/test/java/examples/zip/ZipFileWritingTest.java
@@ -30,7 +30,6 @@ public void testWritingZipFile() throws IOException {
         // first we create and write the local file header
         long positionOfLocalFileHeader = buffer.position();
         LocalFileHeader fhFile = new LocalFileHeader();
-        fhFile.setSignature(ByteBuffer.wrap(new byte[]{ 0x50, 0x4b, 0x03, 0x04 }));
         fhFile.setFileName("example.txt");
         fhFile.setCompressedSizeInBytes(fileData.length);
         fhFile.setUncompressedSizeInBytes(fileData.length);
@@ -42,7 +41,6 @@ public void testWritingZipFile() throws IOException {
         // now we need to create the central directory header
         long positionOfFirstCentralDirectoryHeader = buffer.position();
         CentralDirectoryFileHeader cdfh = new CentralDirectoryFileHeader();
-        cdfh.setSignature(ByteBuffer.wrap(new byte[]{ 0x50, 0x4b, 0x01, 0x02 }));
         cdfh.setFileName("example.txt");
         cdfh.setCrc32OfUncompressedData(crc32);
         cdfh.setCompressedSizeInBytes(fileData.length);
@@ -52,7 +50,6 @@ public void testWritingZipFile() throws IOException {
 
         // finally, we need to write the closing end of central directory header
         EndOfCentralDirectoryRecord eocdr = new EndOfCentralDirectoryRecord();
-        eocdr.setSignature(ByteBuffer.wrap(new byte[]{ 0x50, 0x4b, 0x05, 0x06 }));
         eocdr.setOffsetOfStartOfCentralDirectory(positionOfFirstCentralDirectoryHeader);
         eocdr.setNumberOfCentralDirectoryRecordsOnThisDisk(1);
         eocdr.setTotalNumberOfCentralDirectoryRecords(1);

From e4281d81ffcfad8460ed9f30d38efb801d9e4722 Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 12:15:34 +0100
Subject: [PATCH 6/8] Updated readme

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index aa286ec..aad5deb 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@ Define some structures you would like to read/write in a `*.structs` file under
 package com.mycompany.projectx;
 
 struct FileHeader {
-  uint8_t     magic[4];
+  uint8_t     magic[4] const = { 0x50, 0x4b, 0x01, 0x02 };
   uint16_t    numberSections countof(sections);
   FileSection sections[];
 }

From f027c5e52a7a87bbfb56be5679a0228e75429bee Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 12:16:17 +0100
Subject: [PATCH 7/8] Updated readme

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index aad5deb..e1e63f2 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ struct FileHeader {
 struct FileSection {
   SectionType type;
   char        name[32];
-  uint32_t    length sizeof(sectionContent);
+  uint32_t    length sizeof(content);
   uint8_t     content[];
 }
 

From ccd7fd1d49ce0e0f88b0e8065f64ac4d875f3850 Mon Sep 17 00:00:00 2001
From: Marc-Christian Schulze <Marc.Christian.Schulze@gmail.com>
Date: Sun, 1 Dec 2024 12:16:53 +0100
Subject: [PATCH 8/8] Updated readme

---
 README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.md b/README.md
index e1e63f2..644fb9a 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,7 @@ fileHeader.write(buffer);
   * bit fields
   * implement Java interfaces
   * default values
+  * constants
 
 ## Unsupported
 * Unions