How to parse bits #46
Description
Hey,
I played around with you library and wanted to figure out how I can parse a sequence like one byte, then 3 bits and then one byte with Big Endian mode.
I created the following JBBP script:
byte byte1; bit:3 bits; byte byte2; which generated
package org.jbbp; import com.igormaznitsa.jbbp.model.*; import com.igormaznitsa.jbbp.io.*; import com.igormaznitsa.jbbp.compiler.*; import com.igormaznitsa.jbbp.compiler.tokenizer.*; import java.io.IOException; import java.util.*; /** * Generated from JBBP script by internal JBBP Class Source Generator */ public class Example { /** * The Constant contains parser flags * @see JBBPParser#FLAG_SKIP_REMAINING_FIELDS_IF_EOF * @see JBBPParser#FLAG_NEGATIVE_EXPRESSION_RESULT_AS_ZERO */ protected static final int _ParserFlags_ = 0; public byte byte1; public byte bits; public byte byte2; public Example () { } public Example read(final JBBPBitInputStream In) throws IOException { this.byte1 = (byte)In.readByte(); this.bits = In.readBitField(JBBPBitNumber.BITS_3); this.byte2 = (byte)In.readByte(); return this; } public Example write(final JBBPBitOutputStream Out) throws IOException { Out.write(this.byte1); Out.writeBits(this.bits,JBBPBitNumber.BITS_3); Out.write(this.byte2); return this; } }To test this, I used this data: 0x01a100
Binary representation: 00000001 101 00001000 00000 ________ ___ ________ ^ ^ ^ | | byte2 | bits byte1 I want to get
byte1: 1 bits: 5 byte2: 8 but get
byte1: 1 bits: 1 byte2: 20 I used this JUnit Test:
package org.example; import static org.assertj.core.api.Assertions.assertThat; import com.igormaznitsa.jbbp.io.JBBPBitInputStream; import java.io.ByteArrayInputStream; import java.util.HexFormat; import org.jbbp.Example; import org.junit.jupiter.api.Test; class ExampleTest { @Test void test() throws Exception { // 00000001 10100001 00000000 var data = HexFormat.of().parseHex("01a100"); var example = new Example(); example.read(new JBBPBitInputStream(new ByteArrayInputStream(data))); var expected = new Example(); expected.byte1 = 1; // 00000001 expected.bits = 5; // 00000101 expected.byte2 = 8; // 00001000 System.out.println("byte1: " + example.byte1); System.out.println("bits: " + example.bits); System.out.println("byte2: " + example.byte2); assertThat(example).usingRecursiveComparison().isEqualTo(expected); } }Can you help me to use your library to reach my expected outcome? Thank you!