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Diary, January 2021

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Friday, January 1, 2021

Dolmen and burial mounds

Conny and I went walking in the forest near Mander where there used to be a dolmen and where there are several burial mounds. We also went searching for border poles and found the following: We again searched for pole 86-IV, but did not find it. We concluded that it must have been removed.

Saturday, January 2, 2021

Going home

Today, we went home from our stay in Manderveen. We decided to search for two border poles, but while drivingvthrough Germany, Conny thought that she saw some one. At first I dismissed it, thinking we were too far from the border, but than we saw another one. We went back to have a look at them. We visited the followein border poles:

Wednesday, January 6, 2021

Some wet snow

This afternoon, we had some wet snow. It is the first wet snow of this winter. Because temperatures are above zero Celsius, there is no chance the snow will stay on the ground.

Sunday, January 10, 2021

Cloud bow

This afternoon, Conny and I mada a walk through the country side. At one point, while walking with the sun on our backs, we noted some bright spots in the clouds. We noted some other bright spots in some other clouds, and realized that they were on a bow. When we walked further the bow became clearer. We also noticed some slight colouration: red on the outside and blue on the inside. We took several pictures. Above one that I stiched together (with Hugin) from two pictures. At home, I concluded that the phenomenon we saw was like a fog bow, or also called a white rainbow. Because it was not in the fog, but in a cloud, I would call it a cloud bow.

Tuesday, January 12, 2021

Palindrome date

Today is palindome date of the form (D)D-(M)M-YY and/or YY.(M)M.(D)D: 12-1-21 and/or 21.1.12. This year there are nine other palindrome date like this and six other special dates, one of which we already have had. All of these, including today, are: There are also a lot of palindrome dates of the format M(M)/D(D)/YY in January and December (besides some already mentioned above):

Wednesday, January 13, 2021

Literate programming with Markdown

On March 20, I am going to give a (online) workshop on parsing. The workshop will start of with a overview of parsing and than explain the decision I took for implementing IParse. In the second part of the workshop, will consist of writing some simple grammar for IParse and test it on input. I am thinking about discussing RawParser, a reimplementation of IParse in 'raw' C, in the last part of the workshop. In the past months I have been working on RawParser and trying to add extensive documents to explain how it works, but I do not feel very happy about all the restrictions that C imposes on the order and level of detail you have to provide. A few days ago, I came across Build Your Own Text Editor and was rather charmed by it approach. It is generated from a collection of Markdown files and a steps.diff file with the help of a program called leg. This made me think about using Markdown as the primary source of the code and write a program to generate a C program from a collection of Markdown files as a form of literate programmin. I think it is possible to make the program smart enough to reorder the Markdown code fragments and to allow a mechanism for extending the code without having to include many instructions where to include which piece of the code as in CWEB, a computer programming system created by Donald Knuth and Silvio Levy as a follow-up to Knuth's WEB literate programming system. I have started this approach on RawParser/docs/ file. As a positive side effect, working on this did result into some improvement of RawParse.c itself.

Saturday, January 16, 2021


Yesterday, on the news there was an issue about how today a snow front would go over the country from the west to the east. Yesterday morning, I already saw some small snow specks fall from the sky, some of which stayed on the roofs of the houses. In the evening, I made some curly kail hotchpotch (with no fried pork but with smoked sausage). Only in the evening, it started to snow and some of it on the roads. At least about 2.5cm of snow fell during the evening, based on my own measurement. The coming days the temperature is going to rise and the snow is expected to quickly melt away.

Saturday, January 17, 2021

Uncontrolled spread

The authorities reported that the spread of the VUI - 202012/01 COVID-19 variant in the Netherlands is no longer contained. They estimate that now about 10% of the COVID cases are the VUI - 202012/01 variant. I am not surprised about this. The authorities have over and over failed in this respect. They are expecting that by April it will be the dominant variant leading to next wave and advising the government to take new measures. The government is thinking about a curfew from 20:00 till 4:00. The experts of the RIVM should have realized that the new variants with higher infection rates were to arise and plan ahead to counter this. As far as I know, they did not do anything. They even did not enough screening of variants to detect the development of mutations. And once the new variant was discovered, they failed to scale up testing to contain this variant. It seems that they only thing they did was to estimate the spread of the new variant in order that they could adise the government with respect to measures to be taken. That can be seen as a clever strategy to avoid their primary responsibility to contain the spread of infectious diseases. Over and over again our government has failed to contain the spread of the virus by means of testing and contact research. It is only since a few months that people who do not have symptoms can be tested.

Wednesday, January 20, 2021

Software engineering is mostly a craft

In my experience as a software engineer for many years, I feel that software engineering is still heavily relying on craftmanship to such an extend that it barely can be called engineering. With engineering, I understand a well defined process to arrive at a reliable solution for a well specified problem by applying a standard set of methods. Of course, software engineering is operating in a context where the problem specification is volutile and usually not well understood from the start of a project. But that can also be seen as a motivation for a more enginering based approach to quickly respond to changing requirements. Currently, most software development is done by writing code, which contains the specified problem and its implementation mixed in such away that it is often not possible to see which is which. So far, not many tools have been developed for a more engineering approach to software engineering. Almost every day new programming languages are proposed, but most of these are just new combinations of language construct in other languages and/or an alternative way to implement them. Most of these languages end a silent death. Most of the software engineering of today is related to data management, where multiple people operate on a shared data repository, either through websites or dedicated applications. Although there are some no-code development platforms they usually work with simple data models. There are some low-code development platforms that are more promesing. (One that I know of is the one developed by ThinkWise.) I believe that these platforms can only succesfull if they are based on rich semantic models. These kind of no/low-code platforms implement just one implementation strategy from a high-level specification to an executable platform. What I am thinking of is the development of languages that specify how a high-level specification can be implemented using lov-level programming languages. I understand that this is a very hard problem. I have started developing a data specification language, which I called DataLang, a name that also has been used for similar approaces. An introduction to this can be found here.

Palindrome dates

Today is a palindrome date when written in the (M)M/(D)D/(YYY)Y format: 1/20/2021.

Thursday, January 21, 2021

Curfew effectiveness

In the document COVID-19, 25e Tweede Kamer briefing, 20 jan 2021 (in Dutch), yesterdays technical briefing of the RIVM to House of Representatives of the Netherlands, it mentions (on page 28) some statistics with respect to nonpharamceutical interventions against COVID-19. On the page there references to scientific publications: The effectiveness of eight nonpharmaceutical interventions against COVID-19 in 41 countries, Ranking the effectiveness of worldwide COVID-19 government interventions, Early assessment of the impact of mitigation measures to control COVID-19 in 22 French metropolitan areas, October to November 2020, and An Early Assessment of Curfew and Second COVID-19 Lock-down on Virus Propagation in France. I presume that the graph presented on the page is based on the data from these (and possible other) publications. It clearly shows that mandating to wear masks in (some) public spaces is not very effective. And also that the effectivess of stay-at-home order (with exemptions) on the reproduction number is about 20%. At the moment there is no strong support for a curfew in the House of Representatives of the Netherlands, because there are doubts about the effectiveness with respect to impact of the measure, which in the Netherlands with a strong culture of personal freedom and choice, is seen as a last resort type of measure.

Book with map

Conny gave me book Trajecten door Utrecht 7 written by D.T. Koen and J. Renes in Dutch and published by Het Utrechts Archief in 2003, ISBN:9076366128. With the book there is a reproduction of a map of the province of Utrecht from 1743 (second edition).

Saturday, January 23, 2021

Schoonebeker Diep

Conny and I travelled along the Schoonebeker Diep at the border of Germany, which is actually the part of the Grenzaa river, which starts in Germany, that is on the border. We followed it in search of border poles. Because the border is in the middle of the river, border poles were placed in pairs at both sides of the river, where the exact middle of the two poles signifies the position of the border. In some cases, only the pole on the Dutch side is left. We followed the book Op zoek naar grenspalen and maps from Topografische atlas van Drenthe proved very helpful. There is a biking path along a large part of the river. We traveled by car and could not follow the river over the whole distance but had to use the road from Coevorden to Nieuw-Schoonebeek. We failed to locate the border pole 152-I. We made a short walk through the center of Nieuw-Schoonebeek. We found the following border poles (and two shields on a bridge).

Afterwards, we traveled to the Germany village Neugnadenfeld where we visited two graveyards. During the second world war it was the location of a prisoner of war camp with primarily Russian soldiers. Because Russia had not signed the First Geneva Convention, the Russian solders were not protected by it. As a result of this, many died and were thrown in a mass grave. After the war, members of the Moravian Church from Germany and other parts of (Eastern) Europe were granted the establish a village at the location of the camp. At their graveyard people are buried in order of their date of death and the graves have simple and similar looking tombstone. There is a rahter strong constrast between the two graveyards.

Friday, January 29, 2021


At 13:42:16, I bought the following books from the Taschen: These are not the type of books that I would normally buy, but because I have bookshops (as non-essential shops) have been closed since December 15, I could not resist the urge to buy some books.

Sunday, January 31, 2021

Online interactive parser

In the past weeks, I worked on an reimplementation of IParse in JavaScript as an online interactive parser for educational purposes, which I am going to use this for workshop that I will be giving for TkkrLab on Saturday, March 20.

This months interesting links

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