Random Computer Rambles

Computer science is the study of algorithmic processes, computational machines and computation itself.

• What is Computer Science? - Computer Science, University of York

Theoretical computer science (TCS) is a subset of general computer science and mathematics that focuses on mathematical aspects of computer science such as the theory of computation, lambda calculus, and type theory. – Wikipedia

Computational Linguistics (Stanford Encyclopedia of Philosophy)

Human knowledge is expressed in language. So computational linguistics is very important. – Mark Steedman, ACL Presidential Address (2007)

Computer Programming

Computer programming is the process of designing and building an executable computer program to accomplish a specific computing result or to perform a specific task. Programming involves tasks such as: analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms in a chosen programming language (commonly referred to as coding).

• wiki <-

• find a few good bloggers in your field of choice, and take some time to understand what they're doing and why.
• Prevent Default

• Github, AWS, Google Cloud, Azure.. are all excellent tools.
• These services become a core part of your deployment pipeline, many of them are quite complex. The features you use are likely to be based on a subscription (monthly/yearly fee), pay-as-you-go model (Gb, /Hr), or even through a third-party extension (/gasp).
• These factors lead to a new level of meta-programming in which you create hacks to support your workflow, reduce costs, and integrate with your internal infrastructure. This is the 10th circle of Hell in which engineers and network specialists need to Read The Docs and become subject matter experts themselves.
• Is there a better way?
  • For conventional orgs, probably not.
  • For the one-man army or isolated tribe of hackers.. perhaps.
    • Build it yourself!
    • Own your data.
    • Develop in distributed silos or 'labs'.
    • Self-host services.

• A wonderful visual history reference

• ChaCha variant - most common stream cipher nowadays.

Public Key Infrastructure - Wikipedia

• defines some familiar elliptical curves for practical security, including in TLS. They work at ~128-bit and ~224-bit security levels.

• AEAD descriptions - we're usually going for a form of this approach with MAC+Encrypt

• HMAC - often used with MD5, SHA-1, etc, plus a secret shared key. Key Hashing

• Digital Signatures - IBM

• Wikipedia

• There are exceptions to this of course - Emacs-lisp is a big one considering that best-practice is often to vertically align elements.

  For example, this is considered good formatting:

  (format "%a %b"
          thing1
          thing2)
  

  And this is bad formatting:

  (format "%a %b"
   thing1
   thing2)
  

  In fact, adding my strict 2-space preference would be even worse formatting.

• Makefiles are another good example. the TAB character is the default indent, so you can either accept it or add an assignment for the special variable .RECIPEPREFIX that gets added to all of your Makefiles. I go for the former since it has better integration with IDEs (which often expect TABs and may warn you about invalid syntax, despite the .RECIPEPREFIX assignment)

• Functional https://en.wikipedia.org/wiki/Functional_programming

• FORTRAN
• OOP https://en.wikipedia.org/wiki/Object-oriented_programming Object-oriented Programming (OOP for short) is a programming model that organizes code around objects, and emphasizes the focus on objects that we want to manipulate, rather than the functions and logic necessary to manipulate them.
  • Objects Objects can be definied as data fields that have unique attributes and behavior. They are most often identified through data modeling, which is the practice of organizing an Information system by applying a variety of formal techniques.
  • Principles of OOP
    • Encapsulation
    • Abstraction
    • Inheritance
    • Polymorphism

Array-based

In computer science, array programming refers to solutions which allow the application of operations to an entire set of values at once. Such solutions are commonly used in scientific and engineering settings. – Wikipedia

• languages include Fortran, APL, J, K, Octave, BQN
• opposed to scalar languages like C and Pascal with can apply operations only to single values, so need to make use of control structures such as indexing and looping.

• what – The prose programming paradigm
• ~
• wiki
• literate programming flow
  

• linker sections:
  • text contains the program instructions
  • rodata contains constant values like strings
  • data contains statically allocated variables whose initial values are not zero
  • bss also contains statically allocated variables whose initial values are zero
  • vector_table is a non-standard section that we use to store the vector (interrupt) table
  • ARM.attributes and the .debug_* sections contain metadata and will not be loaded onto the target when flashing the binary.

Redditor comment regarding the C++ ecosystem

• This Redditor with 12y of XP writing C++ talks about all the

complexities involved with coding in C++. OP is asking about some of the nuances of Rust vs. C++, and our Redditor avoids regurgitating the common arguments that are given for Rust in favor of C++ - namely Memory Safety and Data Races. A fitting quote from Nietszche is given as explanation for not addressing those issues:

Whoever fights with monsters should see to it that he does not become a monster in the process. And when you gaze long into an abyss the abyss also gazes into you

– Friedrich Nietzsche

the rustc book

• rustc is the Rust compiler. It is rarely invoked directly by the programmer, but rather indirectly through Cargo. Use the --verbose flag to see how rustc is called, for example in:

  cargo build --verbose
  

• The compiler has many options.

  rustc --help    
  

  Usage: rustc [OPTIONS] INPUT
  
  Options:
      -h, --help          Display this message
  	--cfg SPEC      Configure the compilation environment
      -L [KIND=]PATH      Add a directory to the library search path. The
  			optional KIND can be one of dependency, crate, native,
  			framework, or all (the default).
      -l [KIND[:MODIFIERS]=]NAME[:RENAME]
  			Link the generated crate(s) to the specified native
  			library NAME. The optional KIND can be one of
  			static, framework, or dylib (the default).
  			Optional comma separated MODIFIERS
  			(bundle|verbatim|whole-archive|as-needed)
  			may be specified each with a prefix of either '+' to
  			enable or '-' to disable.
  	--crate-type [bin|lib|rlib|dylib|cdylib|staticlib|proc-macro]
  			Comma separated list of types of crates
  			for the compiler to emit
  	--crate-name NAME
  			Specify the name of the crate being built
  	--edition 2015|2018|2021|2024
  			Specify which edition of the compiler to use when
  			compiling code.
  	--emit [asm|llvm-bc|llvm-ir|obj|metadata|link|dep-info|mir]
  			Comma separated list of types of output for the
  			compiler to emit
  	--print [crate-name|file-names|sysroot|target-libdir|cfg|target-list|target-cpus|target-features|relocation-models|code-models|tls-models|target-spec-json|native-static-libs|stack-protector-strategies|link-args]
  			Compiler information to print on stdout
      -g                  Equivalent to -C debuginfo=2
      -O                  Equivalent to -C opt-level=2
      -o FILENAME         Write output to <filename>
  	--out-dir DIR   Write output to compiler-chosen filename in <dir>
  	--explain OPT   Provide a detailed explanation of an error message
  	--test          Build a test harness
  	--target TARGET Target triple for which the code is compiled
      -A, --allow LINT    Set lint allowed
      -W, --warn LINT     Set lint warnings
  	--force-warn LINT
  			Set lint force-warn
      -D, --deny LINT     Set lint denied
      -F, --forbid LINT   Set lint forbidden
  	--cap-lints LEVEL
  			Set the most restrictive lint level. More restrictive
  			lints are capped at this level
      -C, --codegen OPT[=VALUE]
  			Set a codegen option
      -V, --version       Print version info and exit
      -v, --verbose       Use verbose output
  
  Additional help:
      -C help             Print codegen options
      -W help             Print 'lint' options and default settings
      -Z help             Print unstable compiler options
      --help -v           Print the full set of options rustc accepts
  
  

• mermaid.js-powered inline dot

std::todo - Rust

• todo macros for code that is not yet written - unimplemented!

makes no such claims.

APL is the OG array PL

• inspired many other modern languages and concept models from spreadsheets to functional to DSLs.
• A Programming Language, 1962
  

Applied mathematics is largely concerned with the design and analysis of explicit procedures for calculating the exact or approximate values of various functions. Such explicit procedures are called algorithms or programs. Because an effective notation for the description of programs exhibits considerable syntactic structure, it is called a programming language.

• APLcart - Find your way in APL
• Talk:APL - HaskellWiki
• APL and Haskell quick comparison
  https://youtube.com/watch?v=QtvvQ7MdwKY
• APL keyboard layout
  
• TryAPL
• some great youtube tutorials and problem walkthroughs available from code_report
• Essays/Incunabulum - J Wiki

expressions

+-×÷⋆√˜⁼˙∘

• literals = char, num
• primitives = functions, modifiers
• 1-modifiers = superscript
• 2-modifiers = unbroken circlers
• other primitives are always functions
• to try out BQN, use the BQN online REPL it's helpful with debugging since it shows the interpreted structure via evaluation diagram

• BQN's grammar is governed by syntactic roles.

  Precedence	Role	Input roles	Output role	Associativity
  0	()	Whatever	Same thing	(none)
  1	Modifier	Function, subject	Function	left-to-right
  2	Function	Subject	subject	Right-to-left

lists

∾≍⌽↕¨´

• companies made with 1d (K) by Arthur Whitney : Kx Systems , shakti

• a string is a list of characters

  "Text!" 
  

• list notation uses angle brackets, ',', newline, and '⋄' are interchangeable separators

  ⟨ π, ∘, "element" ⋄ ⟨'l',1,5,'t'⟩ ⟩
  

• strands are an alternative notation for lists: '‿'

  >> 2 × ⟨0‿2 ⋄ 1‿3‿5⟩
  ⟨ ⟨ 0 4 ⟩ ⟨ 2 6 10 ⟩ ⟩
  
  >> ⟨ 10, 20‿30 ⟩ + ⟨ 1‿2, 3 ⟩
  ⟨ ⟨ 11 12 ⟩ ⟨ 23 33 ⟩ ⟩
  

• '≍' is the function for making one or two atom arguments into a list. Solo in the one-arg case, couple in the two.

• '∾' is Join To (inverted lazy S), which concatenates lists

  >> ⟨1,2,3⟩ ∾ "abc"
  ⟨ 1 2 3 'a' 'b' 'c' ⟩
  
  >> 0 ∾ ⟨1,2,3⟩
  ⟨ 0 1 2 3 ⟩
  
  >> "plural" ∾ 's'
  "plurals"
  

• '⌽' is Reverse - puts a list back to front

  >> ⌽ "drawer"
  "reward"
  

  with a left argument, means Rotate which shifts values over by a specified amount. positive rotates left, negative roates right.

• '¨' is the 1-modifier Each which applies the operand to every element of a list argument - it's the same as map in a functional programming language. with two list arguments (with the same length), the elements of each list are paired - like a zip function.
• '´' is Fold - reduce or accumulate functions such as `+´` which sums a list
• '↕' Range - returns all natural numbers less than subject
  • natural numbers start at 0 (naturally)

combinators

<>≠=≤≥≡≢○⊸⟜

Tacit programming does not use variables during the execution of a function (but you might use them for convenience in order to construct a tacit program). Variables allow you to use any accessible value in the program with the same level of ease. Tacit code doesn't. In fact it becomes pretty unusable when more than about three values are active at once. One consequence is that tacit code won't cause confusion by modifying far-away variables. But something unique to the tacit paradigm is that when only a small number of values are active—which is always true in a small enough portion of a program!—it has more powerful ways to describe the way these values flow through the program. The main way it achieves this is with combinators.

• booleans are represented by the natural numbers 0 and 1, no built-in primitives for this. the concept and power behind this is seen in how counts and occurences work -

  >> 'e' = "George Boole"
  ⟨ 0 1 0 0 0 1 0 0 0 0 0 1 ⟩
  
  >> +´ 'e' = "George Boole"
  3
  
  >> 'e' +´∘= "George Boole"  # With a combinator
  3
  
  

• '⋆⟜-' is "Power After Negation"
• '⋆⊸-' is "Exponent Before Subtracting"
• of course have one-arg or two arg-case of Before and After, structure of application is the same.

• introduced the Not function - holy crap! ¬x == 1-x gives us multiple ways to write some interesting things

  >> ¬⊸× 0.5
  0.25
  

• reintroducing fact that modifiers can be assigned to data values, also, data values can be applied as functions. specifically constant functions that just return themselves

• consider the following improvement to a previous example for use of number as const function using Range

  >> ↕⊸÷⟜(-⟜1) 8
  ⟨ 0 0.14285714285714285 0.2857142857142857 0.42857142857142855 0.5714285714285714 0.7142857142857143 0.8571428571428571 1 ⟩
  

  or with a train, simply

  (↕÷-⟜1) 8
  

  our new base-decode function:

  (@+ ·+⟜(2⊸×)´∘⌽¨ -⟜'0') "01000010"‿"01010001"‿"01001110"
  

• using a data value as the left operand of Before or the right operand of After is called Bind because it attaches that data value as an argument to the other operand

variables

∧∨¬⊣⊢↑↓«»⌾

To take a proud denizen of the eternal cosmos of values, held for a fleeting instant by the course of code, and bind it. Tie it down with a name, failing always to alter its inner nature but allowing context to reform its outer appearance. So labelled, perhaps through the progress of time it will know escape, or else find itself passed through one bond to another, ever tethered. It's a task to be approached only with respect.

>> hey ← "Hi there"

>> hey ∾ ", World!"
"Hi there, World!"

> lol

• ← is used for declare and assign
• ↩ is just assign (after already declared)
• oh my variables have roles too
  • lowercase = subject
  • Uppercase = function
  • _leftUnderscore = 1-modifier
  • \_twoUnderscores = 2-modifier

Using embedded BQN

Probably you can figure out the easy things like calling bqn("×´1+↕6") to compute six factorial. But how do you get JS and BQN to talk to each other, for example to compute the factorial of a number n? Constructing a source string with bqn("×´1+↕"+n) isn't the best way—in fact I would recommend you never use this strategy.

Instead, return a function from BQN and call it: bqn("{×´1+↕𝕩}")(n). This strategy also has the advantage that you can store the function, so that it will only be compiled once. Define let fact = bqn("{×´1+↕𝕩}"); at the top of your program and use it as a function elsewhere.

example of BQN characters

+-×÷⋆√⌊⌈∧∨¬|=≠≤<>≥≡≢⊣⊢⥊∾≍↑↓↕⌽⍉/⍋⍒⊏⊑⊐⊒∊⍷⊔
`˜˘¨⁼⌜´˝˙  ∘⊸⟜○⌾⎉⚇⍟⊘◶⎊
π‿∞‿@↩←⇐→,⋄  𝕨𝕩𝔽𝔾𝕎𝕏𝕗𝕘𝕊𝕤ℝ𝕣⦃⦄⟨⟩

See glyphs.bqn

In computerized society where individuality is diminished, there are those who find little or no satisfaction in strict conformity to stereotyped thinking and are searching for their own answers to life's questions and how best to live, work and find inspiration.

Although little is known about what transpired during his brief visit to the Northern Venice, the idea Arthur conceived during that trip is much better known — he had a clear and uncompromising vision of a new system.

In 1992, Whitney departed from Morgan Stanley to fully concentrate on the design of a new computer language.

• you can download the evaluation version of shakti for 30-days without charge. The enterprise version is where some of the premium features are though.

• Shakti (k9) tutorial

• As far as I know, Arthur is working more heavily on the DB side - kdb+ has web APIs, FFI (for Rust too!), IPC, ML, you name it. shakti plays well with these.

• Loading Objects : You can load dynamic objects into Makefiles with the load keyword.
  • Such an object might include new make functions and a 'setup' function for registering them with GNU make's function handling system.