I'm trying to think about what a reasonable GUI for this would even look like. What kinds of controls and displays make sense for helping to develop and debug a schema of this nature?
Brainstorming... Stretching every x-bits to be 8-bit and aligned (so we can display them). For example for x=7, a starting address as a bit offset, the number of bits to process, and if the LSB (least-significant-bit-first bit order) is on the right (last) or left (first), we can stretch 7-bit ASCII so we can see the text. I can envision a GUI viewport where we see the bits, maybe a click and drag to select some range of bits (this is going to depend on LSB location), then apply some function like this "bit stretcher" and have another viewport with the stretched results. I see you, Steve, and others have developed https://github.com/DFDLSchemas/mil-std-2045 so we have some examples of how DFDL is supposed to parse that kind of data. What tools would you like to see in the debugger that would facilitate developing and debugging these schemas? Wireframing this out will be extremely helpful. -Davin On 9/26/22, 6:32 PM, "Mike Beckerle" <mbecke...@apache.org> wrote: I wanted to share this bits dump so that people working on VSCode and the data display aspects can see what kind of data display some users are needing in order to debug data of late. We've written little tools to create this for us in order to debug DFDL schemas for mil-std-2045 and other mil-std data formats that use bitOrder 'leastSignificantBitFirst' and are not byte oriented. These formats never waste a bit. Absolutely nothing is byte aligned ever. Text strings are infrequent, but when they do occur 7-bits per character, packed together with no wasted bits, is typical. ******* Data Dump ********* 3322 2222 2222 1111 1111 1100 0000 0000 addr bitPos 1098 7654 3210 9876 5432 1098 7654 3210 hex dec(0b) ------------------------------------------------------------ 0000 0000 0000 0000 0000 0001 0110 0010 :00000010 128 0101 0010 1110 0110 1100 1101 0100 1101 :00000014 160 0101 0011 0011 0001 1001 0000 0001 0001 :00000018 192 1000 0001 0001 1011 1100 1000 0000 0000 :0000001c 224 0000 0000 0000 0000 0010 1011 0000 0000 :00000020 256 0010 0001 0000 0100 1000 0110 1100 0100 :00000024 288 0100 0011 0111 1011 1100 0111 0010 0100 :00000028 320 0101 0111 1101 1100 0001 1101 0010 0101 :0000002c 352 0000 1101 0010 0100 1000 1111 1110 1100 :00000030 384 0111 0010 1100 1001 1100 0101 0001 0101 :00000034 416 0101 1000 1011 1010 1111 0011 0010 0010 :00000038 448 1111 1111 1101 0011 0001 1110 0101 1101 :0000003c 480 0001 1100 1111 0100 1110 1000 1010 1000 :00000040 512 1100 0010 1000 0011 1001 1110 1001 0100 :00000044 544 0100 1110 0111 1001 0110 1010 0010 0000 :00000048 576 0000 0011 1111 1111 :0000004c 608 ------------------------------------------------------------ This is a right-to-left display of data where bytes are numbered right to left, and bits are numbered right to left. Text is most often 7-bit ascii, but it is bit packed, and a character begins at any bit position. However, there are also 6 and 5 bit character encodings. The addresses are byte positions, 0-based. The bit positions are decimal, also 0-based. I added the color alternating highlighting of the last characters of this example data which are "This is a Test␡" (which ends with a DEL). This is just by way of showing that it is possible to pick out the 7-bit-wide characters. It also illustrates why there is no text dump along side this bits dump. Because given that a character can start on any bit boundary there's no sensible interpretation of this data as text until you identify the start bit of the first character. Mike Beckerle Apache Daffodil PMC | daffodil.apache.org OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl Owl Cyber Defense | www.owlcyberdefense.com ----------------------------------------------------------------- This message and any files transmitted within are intended solely for the addressee or its representative and may contain company proprietary information. If you are not the intended recipient, notify the sender immediately and delete this message. Publication, reproduction, forwarding, or content disclosure is prohibited without the consent of the original sender and may be unlawful. Concurrent Technologies Corporation and its Affiliates. www.ctc.com 1-800-282-4392 -----------------------------------------------------------------
