Just a note to point out that infix like a+b*c in a conventional programming language is not helpful if a,b,c are symbolic expressions.. Writing it as add(a, mul(b,c)) is not a big deal, nor is writing it in lisp (add a (mul b c)). Of course you need to write programs add and mul, but you have to do that regardless. Languages that are primarily oriented to provide arithmetic on fixed-length integers or double-float numbers, mostly have to be covered over by macros etc to do computer algebra. Languages like FORTRAN, Algol, C.
You could look at RLISP used for Reduce, if you want to see a version of lisp with "syntactic sugar" to look "infix" ish. And that is used for a computer algebra system, Reduce. There is something of a tradition, to hand to someone, perhaps someone who prefers infix, a project to "Write a scanner/parser/code generator for an infix language of your design [ or pick one, say Pascal]" in Lisp. I've done this with programming language/compiler undergraduate classes at Berkeley for decades, with probably thousands of students. It takes 10 weeks, assuming you know no lisp, nothing about lexical analysis, nothing about parsing, nothing about intermediate code generation. and maybe nothing about Pascal. At the completion of the project, most students prefer Lisp's parenthesized prefix. They also understand Pascal better, having written an interpreter and compiler for it. Often they choose to use Lisp for other projects, given a choice. Most criticisms of Lisp come from people who have never used it, and it shows. Complaints about too many parentheses. No, there are just exactly enough, and your editor helps. Or indentation (hi Pythonistas). Editors indent for you, exactly right. Not webby enough (see cl-http or other packages). Too slow (uh, faster than Python, some excellent optimizing compilers for Lisp). Too hard to learn. Think about how much time you spent in learning your current favorite language on the precedence of operators. Or what the operators meant. Or what happens when integers "overflow". Consider learning Lisp. Parts of Macsyma/Maxima are more like 60 years old. Almost as old as Lisp (circa 1959). James Slagle's 1961 PhD on symbolic integration (SAI'NT) includes a substantial section explaining Lisp, which was quite new at the time . On Friday, January 22, 2021 at 11:36:06 AM UTC-8 parisse wrote: > I (almost) do not code C++ myself, probably 99% of my code is C-style, but > I'm using a C++ compiler, that way I can link to the C++ standard template > library and benefit of features like operator overload. Doing so, I do not > have screens of error messages. > > Le vendredi 22 janvier 2021 à 15:07:51 UTC+1, dim...@gmail.com a écrit : > >> On Thu, Jan 21, 2021 at 8:04 PM parisse <bernard...@ujf-grenoble.fr> >> wrote: >> > >> > Well, searching for "lisp infix notation" is not very convincing >> (unless I missed something?), compared to built-in infix support. You might >> prefer Lisp to C/C++, it's your choice, but I don't see any objective >> reason that one should stay away from C/C++. And Giac is a proof that one >> can actually write a CAS in C/C++, that compares very well with the >> Lisp-based CAS Maxima. >> >> Maxima is ~40 years old with a bit of work done since then, but the >> core is that old, as far as I know: >> https://en.wikipedia.org/wiki/Macsyma >> >> As for staying away from C++, most people who might be trying to do >> something with supposedly state of the art library like boost, >> would run away screaming, closely followed by 100 screens of error >> messages :-) >> Or, now mostly gone (?), iterator_traits (my closest encounter with >> C++, contributing to CGAL, 20 years ago, where these had to be >> generated by a script for some classes, otherwise compilers kept >> crashing...) >> >> >> >> >> >> > Le jeudi 21 janvier 2021 à 18:07:14 UTC+1, dim...@gmail.com a écrit : >> >> >> >> On Wed, Jan 20, 2021 at 7:13 PM parisse <bernard...@ujf-grenoble.fr> >> wrote: >> >> > >> >> > As the author of a CAS, I can state that you need much more than 2 >> weeks to learn a programming language to make a CAS, and much much more if >> you want to be fast. Life is short, therefore choose your programming >> language carefully! I don't regret my choice for C (+ C++ STL and operator >> redefinition) made 20 years ago, because C can interact with a lot of >> languages (including compilation to Javascript). If I had to choose today, >> I would perhaps choose Julia. Not Python, it's much too slow. I don't know >> for Lisp speed, but it's not a language I would choose anyway, I like to >> write e.g. a+b*c when I do algebraic computations in my source code. >> >> >> >> There are macro packages for infix maths in Common Lisp, so this by no >> >> means should be a deal-breaker for anyone. >> >> >> >> Needless to say, C++ has its own can of worms, which anyone who tried >> >> to used it might easily produce, as a reason to stay >> >> away from it. >> >> >> >> > >> >> > Le mercredi 20 janvier 2021 à 19:47:01 UTC+1, rjf a écrit : >> >> >> >> >> >> I think you have to figure that there is a difference in >> productivity of people who just learned Python in high school and would >> really like to write a computer algebra system >> >> >> versus people who know more mathematics, are comfortable spending 2 >> weeks learning lisp, spending ?? (weeks? months?) studying the state of the >> art in >> >> >> computer algebra systems as evolved over 60 years, and want to >> contribute to advancing the art (rather than re-programming the easy >> stuff). >> >> >> I am under the impression that learning python is a reasonable >> stepping stone to learning lisp. >> >> >> >> >> >> As far as checking results for various systems, there is a category >> of CAS bugs that are syistem independent. >> >> >> That is, they occur in many systems! Sometimes they depend on >> secretly dividing by zero, or doing something >> >> >> that is invalid at a singularity. So "Maple and Mathematica and ... >> all agree" does not mean they are right! >> >> >> >> >> >> I think my essential point previously is that rewriting easy stuff >> (in a different language) typically fails to push the frontier. >> >> >> >> >> >> >> >> >> >> >> >> On Wednesday, January 20, 2021 at 5:54:51 AM UTC-8 kcrisman wrote: >> >> >>>> >> >> >>>> >> >> >>>> As to the question of replacing backends, there is already a >> ticket (which I cannot find right now, my apologies) which started the >> process of seeing what doctests would fail if we went to Sympy as default. >> Presumably something similar could be done with this engine (I don't know >> if it is more for low-level symbolics or also things like integration). >> >> >>> >> >> >>> >> >> >>> In particular, the (very minimal) documentation (really an API is >> all) makes it seems more a replacement for things like Ginac (already in >> C++), not Maxima et al. I don't know if that would provide a noticeable >> speedup per se, though the SageManifolds ticket mentioned parallelization >> so perhaps it is better suited for that? >> >> > >> >> > -- >> >> > You received this message because you are subscribed to the Google >> Groups "sage-devel" group. >> >> > To unsubscribe from this group and stop receiving emails from it, >> send an email to sage-devel+...@googlegroups.com. >> >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/sage-devel/879dd941-95a0-4f2f-b5ac-96f60439f80dn%40googlegroups.com. >> >> >> > >> > -- >> > You received this message because you are subscribed to the Google >> Groups "sage-devel" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to sage-devel+...@googlegroups.com. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/sage-devel/53e6e905-27ec-4545-a2ef-bca1eb01029cn%40googlegroups.com. >> >> >> > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. 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