Knuth was writing in Pascal, a language that had many limitations (e.g. it didn't even have a proper string type; "array of 15 characters" and "array of 16 char

Knuth was writing in Pascal, a language that had many limitations (e.g. it didn't even have a proper string type; "array of 15 characters" and "array of 16 characters" were distinct types) -- see Kernighan's article "Why Pascal is not my favourite programming language" from about the same time. So he had to implement a lot of the primitives in the program, and also more complicated data structures like a hash trie in this case, and the point was to demonstrate how to do that without the program becoming unreadable. I'm reading some of Knuth's Pascal programs recently and writing down notes for myself; ended up discussing some of these points here: https://shreevatsa.github.io/tex/program/pooltype/#other-problems-with-pascal https://shreevatsa.github.io/tex/program/pooltype/#other-pro... (A slightly better comparison may be with the source code of the Unix programs (tr, wc, etc), rather than with shell pipelines composing those programs.) Read the original sources for more: https://www.cs.tufts.edu/~nr/cs257/archive/don-knuth/pearls-1.pdf https://www.cs.tufts.edu/~nr/cs257/archive/don-knuth/pearls-... https://www.cs.tufts.edu/~nr/cs257/archive/don-knuth/pearls-2.pdf https://www.cs.tufts.edu/~nr/cs257/archive/don-knuth/pearls-... http://www.cs.upc.edu/~eipec/pdf/p583-van_wyk.pdf http://www.cs.upc.edu/~eipec/pdf/p583-van_wyk.pdf