Re: Finite State Machine
I only knew you could use it to write a compiler, or to process command-line parameters. Popular among Unix/Linux :) I did use state-transition diagram to describe some business behavior, for example, the states of an insurance contract. On Thu, Dec 19, 2013 at 12:34 PM, Nicholas Geti ng...@optonline.net wrote: Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/CAGv=MJCjd2g6eSRN=5y8beqam-fyhurjoz+putqk1gkg50u...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
RE: Finite State Machine
A finite state machine/system is one that: a. knows the current status of the machine at all times b. can recognise a state change of the machine c. reacts to a state change via a predetermined set of rules d. triggers a change in state for any state change in (c) above Although this would seem to be how any program/system can be defined, the Finite State Machine (FSM) is very rigid in how it models the system. You need very structured code patterns and usually these are driven via an events table where each event can have a number of states with events being rows and states being columns. The table is scanned via the events handler and the combination of row/column values at any instant in time dictate either a state change or a requirement for a state change. This state change is then handled, normally in an alternative programming thread and the results of the change fed back into the events table. What happens is that the system becomes virtually dynamic with regards to consequential events as there will be a finite but usually very large number of states that have to be processed or recognised. Lots of the mainframe operating systems that I used to work on at Singer used this methodology as did the early microcode mainframes at ICL. The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. Hope this makes sense as although it is a simple concept, the implementation of it is not a trivial task. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Nicholas Geti Sent: 19 December 2013 04:35 To: profox@leafe.com Subject: Finite State Machine Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/18725b8cd2d5d247873a2baf401d4ab22a476...@ex2010-a-fpl.fpl.LOCAL ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
RE: Finite State Machine
Nicholas, I guess that the simplest way of describing it is that: Anything can happen at any time, anywhere, with any thing the rules that govern the changes may or may not be changed in real time by the things which in turn generate a modified set of rules that may or may not act in the way of the original rules. i.e a Dynamic system Note that Finite State doesn't mean finite when it comes to reacting to rules or the number of rules, as the rules themselves can become dynamic. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Nicholas Geti Sent: 19 December 2013 04:35 To: profox@leafe.com Subject: Finite State Machine Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/18725b8cd2d5d247873a2baf401d4ab22a476...@ex2010-a-fpl.fpl.LOCAL ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
Many years ago I programmed factory-floor PLCs (programmable logic controllers) using 'ladder logic'. This sounds sort of like that. ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/1387448485.11395.61481045.1d62d...@webmail.messagingengine.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
Dave, did the IBM mainframe and early microprocessor model of instruction pointer; address / data registers map onto a finite-state machine? I can see how it might be done(e.g. by mapping op codes to microcoded OR/NAND/SHIFT/JUMP etc.), but I don't see why it /would/ be done that way. On 19/12/2013 15:39, Dave Crozier wrote: A finite state machine/system is one that: a. knows the current status of the machine at all times b. can recognise a state change of the machine c. reacts to a state change via a predetermined set of rules d. triggers a change in state for any state change in (c) above Although this would seem to be how any program/system can be defined, the Finite State Machine (FSM) is very rigid in how it models the system. You need very structured code patterns and usually these are driven via an events table where each event can have a number of states with events being rows and states being columns. The table is scanned via the events handler and the combination of row/column values at any instant in time dictate either a state change or a requirement for a state change. This state change is then handled, normally in an alternative programming thread and the results of the change fed back into the events table. What happens is that the system becomes virtually dynamic with regards to consequential events as there will be a finite but usually very large number of states that have to be processed or recognised. Lots of the mainframe operating systems that I used to work on at Singer used this methodology as did the early microcode mainframes at ICL. The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. Hope this makes sense as although it is a simple concept, the implementation of it is not a trivial task. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Nicholas Geti Sent: 19 December 2013 04:35 To: profox@leafe.com Subject: Finite State Machine Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/52b2d6b9.2050...@hawthorncottage.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
RE: Finite State Machine
Andy, Certainly the Singer 10 (which as a stripped IBM 360/148 Front end processor in its native form) when it was upgraded to the 220 by ICL did and it still maintained it's 10 bit architecture which made programming real fun! All the DRS 50 microcode was based on FSM architecture and this was lifted I believe from the 2903 which was ICL's first microcoded mini/mainframe. I can't vouch for the early 2900 ICL series as I never did any work on them to any degree. The wierd thing is that when you are using a FSM system then it can't have any properties if it is to remain pure. A propery merely becomes an additional state but many times have I seen a halfway house solution where properties are used when dealing with software FSM's. One good thing about FSM is that it can only ever possess one state and that is the current state apart from when multi threading, but that adds a whole new bag of worms. The nice thing about the Singer 10 was that FSM handling was extremely rapid because of the 10 bit architecture and we could shift around data much quicker than the IMB equivalent machines ... and we were also completely solid state with genuine core memory so shutting off the machine mid run was not a problem. I do remember though, when the 220 came out, forgetting that it had volatile memory and going through my regular Singer 10 demo and turning off the power, much to the annoyance of my allocated salesman who went pale ... and lots of g uffawing and piss taking as I knew what I had done as soon as I pulled the switch! I remember the customer (the Co-Op) actually said that the cock up actually sold them the system as they realised that we were in fact human, unlike the IBM slicko's who had demonstrated their 360 some days before. Happy days indeed.. Anyway, on a lighter note, how are you doing with your living in, is it Goa lots of the time? Hope you are both well and enjoying the sunshine. Must admit it is a place I'd love to visit and it's on my bucket list! Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of AndyHC Sent: 19 December 2013 11:21 To: profox@leafe.com Subject: Re: Finite State Machine Dave, did the IBM mainframe and early microprocessor model of instruction pointer; address / data registers map onto a finite-state machine? I can see how it might be done(e.g. by mapping op codes to microcoded OR/NAND/SHIFT/JUMP etc.), but I don't see why it /would/ be done that way. On 19/12/2013 15:39, Dave Crozier wrote: A finite state machine/system is one that: a. knows the current status of the machine at all times b. can recognise a state change of the machine c. reacts to a state change via a predetermined set of rules d. triggers a change in state for any state change in (c) above Although this would seem to be how any program/system can be defined, the Finite State Machine (FSM) is very rigid in how it models the system. You need very structured code patterns and usually these are driven via an events table where each event can have a number of states with events being rows and states being columns. The table is scanned via the events handler and the combination of row/column values at any instant in time dictate either a state change or a requirement for a state change. This state change is then handled, normally in an alternative programming thread and the results of the change fed back into the events table. What happens is that the system becomes virtually dynamic with regards to consequential events as there will be a finite but usually very large number of states that have to be processed or recognised. Lots of the mainframe operating systems that I used to work on at Singer used this methodology as did the early microcode mainframes at ICL. The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. Hope this makes sense as although it is a simple concept, the implementation of it is not a trivial task. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Nicholas Geti Sent: 19 December 2013 04:35 To: profox@leafe.com Subject: Finite State Machine Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com
RE: Finite State Machine
Sorry, I think this should probably go [NF] now. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Dave Crozier Sent: 19 December 2013 11:35 To: ProFox Email List Subject: RE: Finite State Machine Andy, Certainly the Singer 10 (which as a stripped IBM 360/148 Front end processor in its native form) when it was upgraded to the 220 by ICL did and it still maintained it's 10 bit architecture which made programming real fun! All the DRS 50 microcode was based on FSM architecture and this was lifted I believe from the 2903 which was ICL's first microcoded mini/mainframe. I can't vouch for the early 2900 ICL series as I never did any work on them to any degree. The wierd thing is that when you are using a FSM system then it can't have any properties if it is to remain pure. A propery merely becomes an additional state but many times have I seen a halfway house solution where properties are used when dealing with software FSM's. One good thing about FSM is that it can only ever possess one state and that is the current state apart from when multi threading, but that adds a whole new bag of worms. The nice thing about the Singer 10 was that FSM handling was extremely rapid because of the 10 bit architecture and we could shift around data much quicker than the IMB equivalent machines ... and we were also completely solid state with genuine core memory so shutting off the machine mid run was not a problem. I do remember though, when the 220 came out, forgetting that it had volatile memory and going through my regular Singer 10 demo and turning off the power, much to the annoyance of my allocated salesman who went pale ... and lots of g uffawing and piss taking as I knew what I had done as soon as I pulled the switch! I remember the customer (the Co-Op) actually said that the cock up actually sold them the system as they realised that we were in fact human, unlike the IBM slicko's who had demonstrated their 360 some days before. Happy days indeed.. Anyway, on a lighter note, how are you doing with your living in, is it Goa lots of the time? Hope you are both well and enjoying the sunshine. Must admit it is a place I'd love to visit and it's on my bucket list! Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of AndyHC Sent: 19 December 2013 11:21 To: profox@leafe.com Subject: Re: Finite State Machine Dave, did the IBM mainframe and early microprocessor model of instruction pointer; address / data registers map onto a finite-state machine? I can see how it might be done(e.g. by mapping op codes to microcoded OR/NAND/SHIFT/JUMP etc.), but I don't see why it /would/ be done that way. On 19/12/2013 15:39, Dave Crozier wrote: A finite state machine/system is one that: a. knows the current status of the machine at all times b. can recognise a state change of the machine c. reacts to a state change via a predetermined set of rules d. triggers a change in state for any state change in (c) above Although this would seem to be how any program/system can be defined, the Finite State Machine (FSM) is very rigid in how it models the system. You need very structured code patterns and usually these are driven via an events table where each event can have a number of states with events being rows and states being columns. The table is scanned via the events handler and the combination of row/column values at any instant in time dictate either a state change or a requirement for a state change. This state change is then handled, normally in an alternative programming thread and the results of the change fed back into the events table. What happens is that the system becomes virtually dynamic with regards to consequential events as there will be a finite but usually very large number of states that have to be processed or recognised. Lots of the mainframe operating systems that I used to work on at Singer used this methodology as did the early microcode mainframes at ICL. The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. Hope this makes sense as although it is a simple concept, the implementation of it is not a trivial task. Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Nicholas Geti Sent: 19 December 2013 04:35 To: profox@leafe.com Subject: Finite State Machine Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts
Re: Finite State Machine
Yes. In 30 years of programming I only met two people who knew what it was. I don't think it is taught in school any more. I would hate to see it disappear which is why I brought up the subject. It has come to my rescue in dozens of situations. Programming and debugging a finite state machine application is almost trivial. The hard part is determining the states. But that part is done with paper and pencil before one begins coding. The books on the subject have relatively simple examples so the student doesn't really see the value of it. Here is an easily understood sample from my experience: My project was for a machining company that used CNC to mill metal parts. Their programmers would prepare the CNC instructions on CAD computers but not being totally skilled in milling techniques there would be mistakes. So they wanted a way to read back and repair the command tapes quickly without having to go back to the CAD programs and try to figure out what went wrong. A programmer was working on this project for a year in Basic using lots of If-Then-Else logic and never got it to work. Using FSM I solved the problem in three days. Unfortunately the IT manager had no clue what I was talking about. On top of that the owner of the company signed papers to sell the company on the day I was to give a demonstration and everything was canceled. Think about it. CNC commands are free-form and streaming. That is, there is a one-byte command followed by one to four digits representing a number such as size of bit, distance to move, coordinates, etc. Try to create the If-Then-Else scenario. If the byte is a command, then look at next byte. Is it a command? Is it is number? And so on for fifteen or twenty commands. It is a rat's next of logic. Decoding/parsing commands such as needed in compilers is a natural for FSM. Real-life examples are much more difficult to find the states but it can be done. I once applied for a job at a firm that does product placement. They contracted with clients to determine how to match products with customers. They would break out patterns of customers: those that liked hot, or salty or special flavors or speed, etc. and tweak the products to match these various categories. The engineer that I interviewed was describing his programming efforts and I said it looked like a situation for the FSM. He immediately jumped out of his seat and said that's exactly what he was doing and ran to fetch his design notes to show me. Nick Geti - Original Message - From: Jean MAURICE jsm.maur...@wanadoo.fr To: profox@leafe.com Sent: Thursday, December 19, 2013 12:21 AM Subject: Re: Finite State Machine I think I do ! In fact I am not sure with the translation. When you have a lot of 'states' and a lot of conditions, you built an array. With one line per state and one column per condition. In each cell of this array, you get the index of the next state you must go and the name of the procedure you must execute. Is that what you are dealing with ? The Foxil [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/B80FE4164F434891A8311CAFB7C30EDF@dual ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On Wed, Dec 18, 2013 at 11:21 PM, Jean MAURICE jsm.maur...@wanadoo.frwrote: I think I do ! In fact I am not sure with the translation. When you have a lot of 'states' and a lot of conditions, you built an array. With one line per state and one column per condition. In each cell of this array, you get the index of the next state you must go and the name of the procedure you must execute. Is that what you are dealing with ? - To me that is a workflow. -- Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/CAJidMYKX=pvtp_xdjbltqfpqrdydv63zjutlsd35wloisns...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On Thu, Dec 19, 2013 at 4:09 AM, Dave Crozier da...@flexipol.co.uk wrote: The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. - I see Taxation at Sales following this methodology. Rigid rules for physical locations all over and you have to charge different rates depending on your customer because you do drop ships for them. -- Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/cajidmy+lsiyzcwvbryyayr54cd88zoi71bn3m9jes0jg1y4...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
RE: Finite State Machine
Stephen, Yes, I believe this model is used in large tax systems as it is to process large queueing systems. We used it because it is flexible and we used to call it Dynamic Jump-pad programming used when memory is at a premium and the coding you start off with in a process isn't necessarily the coding you end up with because the code in te State responses actually can modify an existing set of response code. At the time this really opened my eyes on two fronts. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. This was necessary because we only had 8K of core in those days and so to operate efficiently we didn't want to overlay code from disk back into memory so we dynamically altered code whilst it was in memory. The project was to write an operating system that supported Point of Sale Tills as external nodes, each of which was firing transactions back to a mainframe at any time so the mainframe had to be able to queue the events/transactions effectively. Using conventional if...else topdown technology would never have worked and would have become too large anyway. We ended up streaming 4 FSM program models together in parallel in order to process the transactions which effectively did away with the conventional polling technique that most people would have used to create a solution. Funnily enough, OOP was only a glimmer in the sky at that stage but to all intents and purposes we were using all the OOP techniques in creating a solution to the problem. It must have worked as it was only decommissioned 5 years ago after 25 years of operation on the same hardware!!! Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of Stephen Russell Sent: 19 December 2013 16:17 To: ProFox Email List Subject: Re: Finite State Machine On Thu, Dec 19, 2013 at 4:09 AM, Dave Crozier da...@flexipol.co.uk wrote: The biggest difficulty in writing software this way is not the programming, it is actually defining the finite number of events, states and combinations of the two that will generate a state change that may or may not affect the actual state of the thread that is currently processing the change. - I see Taxation at Sales following this methodology. Rigid rules for physical locations all over and you have to charge different rates depending on your customer because you do drop ships for them. -- Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/18725b8cd2d5d247873a2baf401d4ab22a477...@ex2010-a-fpl.fpl.LOCAL ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On Thu, Dec 19, 2013 at 10:32 AM, Dave Crozier da...@flexipol.co.uk wrote: Stephen, Yes, I believe this model is used in large tax systems as it is to process large queueing systems. We used it because it is flexible and we used to call it Dynamic Jump-pad programming used when memory is at a premium and the coding you start off with in a process isn't necessarily the coding you end up with because the code in te State responses actually can modify an existing set of response code. At the time this really opened my eyes on two fronts. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. This was necessary because we only had 8K of core in those days and so to operate efficiently we didn't want to overlay code from disk back into memory so we dynamically altered code whilst it was in memory. The project was to write an operating system that supported Point of Sale Tills as external nodes, each of which was firing transactions back to a mainframe at any time so the mainframe had to be able to queue the events/transactions effectively. Using conventional if...else topdown technology would never have worked and would have become too large anyway. We ended up streaming 4 FSM program models together in parallel in order to process the transactions which effectively did away with the conventional polling technique that most people would have used to create a solution. Funnily enough, OOP was only a glimmer in the sky at that stage but to all intents and purposes we were using all the OOP techniques in creating a solution to the problem. It must have worked as it was only decommissioned 5 years ago after 25 years of operation on the same hardware!!! - Awesome. I bounce back and forth between easy code and workflow code. We have an asset approval process that s butt ugly in rules that use to be all hard coded. Now have modules that determine state and only get the rules that pertain in this situation. It take a bunch of sign-off here to buy something. # of people required is determined by asset type and cost. -- Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/cajidmyk7ho-vm2wayzk7b6eknb6-tt30dpoxd-jtfaca2jm...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On 19/12/2013 22:02, Dave Crozier wrote: ... At the time this really opened my eyes on two fronts. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. snip At the time this got me really slapped on the wrist. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. Self modifying code was a real memory saver and a real No-No for the newly invented programming standards wonks. A couple of years later I was put in charge of ... programming standards - and I made it a rule 'no self modifying code' - so a lass (yes there were female programmers in the neolithic!) whose program was at the memory limit *moved some code into the data area, modified it, and executed it there* - then defied me to rule it out of order bg bl**dy 'L - that took me back! ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/52b323c3.5070...@hawthorncottage.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On Thu, Dec 19, 2013 at 2:21 AM, Alan Bourke alanpbou...@fastmail.fm wrote: Many years ago I programmed factory-floor PLCs (programmable logic controllers) using 'ladder logic'. This sounds sort of like that. I was going to make a joke and give an example such as: do while .t. enddo and call it good g I *think* I've heard of FSM in the past but perhaps not. I know I never studied the concept in college as I was a Math major not Comp Science Interesting stuff, especially as I see some of the practical examples ya'll are putting out there... -- Matt Jarvis Eugene, Oregon USA ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/capt54rzv32+ekboaqxuc6e59qruj0osxuqrv6pbt5glw+jk...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
RE: Finite State Machine
Just to bring this thread back onto VFP, the O/S had a built in ISAM (Index Sequential Access Method) built into it which closely resembled VFP Files and indexes. On top of this we built a high level language to manipulate the ISAM files which virtually has a one to one with the early Foxbase DBASE products on a database level i.e seek, find, browse, insert, delete etc. it was at that time that I decided that any language that I was to do development of desktop apps on would have to have these facilities built into it and some years after I discovered Dbase II and Foxplus which was like a gift from god! Dave -Original Message- From: ProFox [mailto:profox-boun...@leafe.com] On Behalf Of AndyHC Sent: 19 December 2013 16:50 To: profox@leafe.com Subject: Re: Finite State Machine On 19/12/2013 22:02, Dave Crozier wrote: ... At the time this really opened my eyes on two fronts. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. snip At the time this got me really slapped on the wrist. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. Self modifying code was a real memory saver and a real No-No for the newly invented programming standards wonks. A couple of years later I was put in charge of ... programming standards - and I made it a rule 'no self modifying code' - so a lass (yes there were female programmers in the neolithic!) whose program was at the memory limit *moved some code into the data area, modified it, and executed it there* - then defied me to rule it out of order bg bl**dy 'L - that took me back! [excessive quoting removed by server] ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/18725b8cd2d5d247873a2baf401d4ab22a477...@ex2010-a-fpl.fpl.LOCAL ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
The thinking about states in the FSM is similar to that in VFP. It is object-oriented style. The advantage of the FSM is the small size of the engine to drive it. One doesn't need a full blown OOP like VFP to write an app. Most of the logic is in arrays holding the state information. Note that moving from one state to the next also includes the ability to execute an output function just like in OOP so you need to code the output functions. Another problem with thinking in VFP is that commercial frameworks are based on forms so now everything looks like a form. Not all apps require forms such as the examples I mentioned in my last note. Nick Geti - Original Message - From: Stephen Russell srussell...@gmail.com To: ProFox Email List profox@leafe.com Sent: Thursday, December 19, 2013 11:46 AM Subject: Re: Finite State Machine On Thu, Dec 19, 2013 at 10:32 AM, Dave Crozier da...@flexipol.co.uk wrote: Stephen, Yes, I believe this model is used in large tax systems as it is to process large queueing systems. We used it because it is flexible and we used to call it Dynamic Jump-pad programming used when memory is at a premium and the coding you start off with in a process isn't necessarily the coding you end up with because the code in te State responses actually can modify an existing set of response code. At the time this really opened my eyes on two fronts. a. The strength and versatility of assembler coding b. The ability of a program to effectively learn by modifying itself. This was necessary because we only had 8K of core in those days and so to operate efficiently we didn't want to overlay code from disk back into memory so we dynamically altered code whilst it was in memory. The project was to write an operating system that supported Point of Sale Tills as external nodes, each of which was firing transactions back to a mainframe at any time so the mainframe had to be able to queue the events/transactions effectively. Using conventional if...else topdown technology would never have worked and would have become too large anyway. We ended up streaming 4 FSM program models together in parallel in order to process the transactions which effectively did away with the conventional polling technique that most people would have used to create a solution. Funnily enough, OOP was only a glimmer in the sky at that stage but to all intents and purposes we were using all the OOP techniques in creating a solution to the problem. It must have worked as it was only decommissioned 5 years ago after 25 years of operation on the same hardware!!! - Awesome. I bounce back and forth between easy code and workflow code. We have an asset approval process that s butt ugly in rules that use to be all hard coded. Now have modules that determine state and only get the rules that pertain in this situation. It take a bunch of sign-off here to buy something. # of people required is determined by asset type and cost. -- Stephen Russell . --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/14C4AA84D6F94EC69A1D47BB43E4F77A@dual ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
Your joke is not far off. Just add a call do while currentstate .NE. done currentstate= FSM(event, currentstate, output) ; where FSM returns the next state and execute the output function endwhile I Googled Finite State Machine Looks like a hotbed of information about it. Nick Geti - Original Message - From: M Jarvis brewda...@gmail.com To: profox@leafe.com Sent: Thursday, December 19, 2013 12:05 PM Subject: Re: Finite State Machine On Thu, Dec 19, 2013 at 2:21 AM, Alan Bourke alanpbou...@fastmail.fm wrote: Many years ago I programmed factory-floor PLCs (programmable logic controllers) using 'ladder logic'. This sounds sort of like that. I was going to make a joke and give an example such as: do while .t. enddo and call it good g I *think* I've heard of FSM in the past but perhaps not. I know I never studied the concept in college as I was a Math major not Comp Science Interesting stuff, especially as I see some of the practical examples ya'll are putting out there... -- Matt Jarvis Eugene, Oregon USA --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/241DA8C6F9C04FC08CDB95C841D6648E@dual ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
On Thu, Dec 19, 2013 at 11:17 AM, Nicholas Geti ng...@optonline.net wrote: Your joke is not far off. Just add a call do while currentstate .NE. done currentstate= FSM(event, currentstate, output) ; where FSM returns the next state and execute the output function endwhile In my case that output is actually a request via email to to give a thumbs up or down on the transaction. Depending on the asset we will track comments and cross references through our app and people high atop the totem pole can see what has transpired for this request. -- Stephen Russell Sr. Analyst Ring Container Technology Oakland TN 901.246-0159 cell --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/CAJidMYJ7_QX-8aDtaTari3t9=-yxnhbqc6t6gcjmztom71y...@mail.gmail.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
At 20:34 2013-12-18, Nicholas Geti ng...@optonline.net wrote: Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Yes. Yes. I find it very useful for some forms of parsing. Sincerely, Gene Wirchenko ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/ ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
At 07:38 2013-12-19, Nicholas Geti ng...@optonline.net wrote: Yes. In 30 years of programming I only met two people who knew what it was. I don't think it is taught in school any more. I would hate to see it disappear which is why I brought up the subject. It has come to my rescue in dozens of situations. It might partly be a matter of vocabulary. state transition diagram is another term. It was taught in my computing diploma in the last semester. I had previously used an extended version to implement a calculator. Programming and debugging a finite state machine application is almost trivial. The hard part is determining the states. But that part is done with paper and pencil before one begins coding. GASP! You mean planning in advance? The books on the subject have relatively simple examples so the student doesn't really see the value of it. And complicated examples are a bear to follow. Here is an easily understood sample from my experience: [snipped example] Here are mine. 1) My VFP app needed a string for how credit card transactions are handled. The date had to be substituted in there somewhere once. I used % as an escape character with %d meaning the date and %% meaning a percent character. My FSM validated that the date escape occurred exactly once and that all escape codes were correct and that the string did not end mid-escape. 2) On my computing diploma, I implemented an FSM with additional actions to implement a four-banger calculator. It took three states. It was easy. My classmates who did not know the technique were cursing the assignment. Sincerely, Gene Wirchenko ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/ ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Finite State Machine
Do any of you know the Finite State Machine technique for programming? Has anyone used it to do programming? Nick Geti --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/9F17FCAEACA24E22882A73E638E11B19@dual ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
Re: Finite State Machine
I think I do ! In fact I am not sure with the translation. When you have a lot of 'states' and a lot of conditions, you built an array. With one line per state and one column per condition. In each cell of this array, you get the index of the next state you must go and the name of the procedure you must execute. Is that what you are dealing with ? The Foxil ___ Post Messages to: ProFox@leafe.com Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/52b2826d.6070...@wanadoo.fr ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
