[lib/util] DataWriter.acquire returns Range<byte> internally

aeneas/src/mach/MachDataWriter.v3

@@ -47,10 +47,7 @@ class MachDataWriter extends DataWriter {
 	}
 	def alignAddr(size: int) {
 		var rem = (pos + startAddr) & (size - 1);
-		if (rem > 0) {
-			acquire(size - rem);
-			at(pos + size - rem);
-		}
+		if (rem > 0) skipN(rem);
 	}
 	def posAddr() -> int {
 		return startAddr + pos;

aeneas/src/main/Version.v3

@@ -3,6 +3,6 @@
 
 // Updated by VCS scripts. DO NOT EDIT.
 component Version {
-	def version: string = "III-7.1755";
+	def version: string = "III-7.1756";
 	var buildData: string;
 }

lib/util/DataWriter.v3

@@ -14,38 +14,34 @@ class DataWriter {
 
 	// Write a byte.
 	def putb(data: int) -> this {
-		acquire(1)[pos++] = byte.view(data);
+		acquire(1)[0] = byte.view(data);
 	}
 	// Write two bytes.
 	def putbb(b0: int, b1: int) -> this {
-		var a = acquire(2), p = pos;
-		a[p + 0] = byte.view(b0);
-		a[p + 1] = byte.view(b1);
-		pos = p + 2;
+		var a = acquire(2);
+		a[0] = byte.view(b0);
+		a[1] = byte.view(b1);
 	}
 	// Write three bytes.
 	def putbbb(b0: int, b1: int, b2: int) -> this {
-		var a = acquire(3), p = pos;
-		a[p + 0] = byte.view(b0);
-		a[p + 1] = byte.view(b1);
-		a[p + 2] = byte.view(b2);
-		pos = p + 3;
+		var a = acquire(3);
+		a[0] = byte.view(b0);
+		a[1] = byte.view(b1);
+		a[2] = byte.view(b2);
 	}
 	// Write a 16-bit little-endian integer.
 	def put_b16(data: int) -> this {
-		var a = acquire(2), p = pos;
-		a[p + 0] = byte.view(data);
-		a[p + 1] = byte.view(data >> 8);
-		pos = p + 2;
+		var a = acquire(2);
+		a[0] = byte.view(data);
+		a[1] = byte.view(data >> 8);
 	}
 	// Write a 32-bit little-endian integer.
 	def put_b32(data: int) -> this {
-		var a = acquire(4), p = pos;
-		a[p + 0] = byte.view(data);
-		a[p + 1] = byte.view(data >> 8);
-		a[p + 2] = byte.view(data >> 16);
-		a[p + 3] = byte.view(data >> 24);
-		pos = p + 4;
+		var a = acquire(4);
+		a[0] = byte.view(data);
+		a[1] = byte.view(data >> 8);
+		a[2] = byte.view(data >> 16);
+		a[3] = byte.view(data >> 24);
 	}
 	// Write a 64-bit little-endian integer.
 	def put_b64(data: long) -> this {
@@ -54,19 +50,17 @@ class DataWriter {
 	}
 	// Write a 16-bit big-endian integer.
 	def put_b16be(data: int) -> this {
-		var a = acquire(2), p = pos;
-		a[p + 0] = byte.view(data >> 8);
-		a[p + 1] = byte.view(data);
-		pos = p + 2;
+		var a = acquire(2);
+		a[0] = byte.view(data >> 8);
+		a[1] = byte.view(data);
 	}
 	// Write a 32-bit big-endian integer.
 	def put_b32be(data: int) -> this {
-		var a = acquire(4), p = pos;
-		a[p + 0] = byte.view(data >> 24);
-		a[p + 1] = byte.view(data >> 16);
-		a[p + 2] = byte.view(data >> 8);
-		a[p + 3] = byte.view(data);
-		pos = p + 4;
+		var a = acquire(4);
+		a[0] = byte.view(data >> 24);
+		a[1] = byte.view(data >> 16);
+		a[2] = byte.view(data >> 8);
+		a[3] = byte.view(data);
 	}
 	// Write a 64-bit big-endian integer.
 	def put_b64be(data: long) -> this {
@@ -128,22 +122,17 @@ class DataWriter {
 	}
 	// Write the bytes from the given range to this writer.
 	def putr(data: Range<byte>) -> this {
-		var len = data.length;
-		acquire(len);
-		var a = this.data[pos ..+ len];
-		for (i < len) a[i] = data[i];
-		pos += len;
+		var a = acquire(data.length);
+		for (i < a.length) a[i] = data[i];
 	}
 	// Write {length} zero bytes.
 	def zeroN(length: int) -> this {
-		var a = acquire(length), end = pos + length;
-		for (p = pos; p < end; p++) a[p] = 0;
-		pos = end;
+		var a = acquire(length);
+		for (i < a.length) a[i] = 0;
 	}
 	// Skip {length} bytes.
 	def skipN(length: int) -> this {
 		acquire(length);
-		pos = pos + length;
 	}
 	// Skip 5 bytes for a 32-bit LEB that will be written later.
 	def skip_leb32() -> int {
@@ -153,7 +142,6 @@ class DataWriter {
 	}
 	// Overwrite a 32-bit LEB at the current position.
 	def overwrite_uleb32(val: int) -> this {
-		acquire(5);
 		for (i < 4) {
 			putb(val | 0x80);
 			val >>= 7;
@@ -180,11 +168,13 @@ class DataWriter {
 		if (pos > max) max = pos;
 		else pos = max;
 	}
-	// Acquire {size} bytes of internal storage.
-	def acquire(size: int) -> Array<byte> {
-		var nsize = pos + size;
-		if (data == null || nsize > data.length) refill(this, nsize);
-		return data;
+	// Acquire {size} bytes of internal storage and advance the position.
+	def acquire(size: int) -> Range<byte> {
+		var end = pos + size;
+		if (data == null || end > data.length) refill(this, end);
+		var result = data[pos ... end];
+		pos = end;
+		return result;
 	}
 	// Grow the internal storage to be at least 2X bigger.
 	private def growI2X(nlength: int) -> this {

test/lib/DataWriterTest.v3

@@ -212,10 +212,10 @@ def test_send2(t: LibTest) {
 }
 
 def assertAcquire(t: LibTest, w: DataWriter, n: int) {
+	var prev_pos = w.pos;
 	var a = w.acquire(1);
-	t.asserteq(a, w.data);
-	t.assert(a.length >= 1);
-	t.assert(w.pos + 1 <= a.length);
+	t.asserteq(1, a.length);
+	t.asserteq(1 + prev_pos, w.pos);
 }
 
 def test_acquire(t: LibTest) {