First language Raku tutorial.md

Programs in a nutshell:

• input
• computation
• output

Of course they don't have to happen only once/in a strict order.

The nature of the computation: two approaches a. the input is reflected in inner state changes - "imperative style" b. the input is transformed into the output using pure functions - "functional style"

Metaphysical background:

• in math, a = a + 1 doesn't make sense
• however, in nature, things are in constant change
  • my age changes
  • well, my birth date doesn't...
  • ... but then time itself does
• we assume that the laws of physics don't change and numbers definitely don't
• Ship of Theseus will return a couple of times

Practical consequences:

• FP
  • data dependencies are more transparent -> better concurrency
• IP
  • the basic paradigm of CPU's -> easy to make fast

Let's start with values:

• most important property: cannot change (plain values)
• types (in Raku)
  • Numeric: Rat, FatRat, Complex, Num, Int...
  • Textual: Str
  • composite structures (if they consist of plain values only)
    • List, Map
      • only according to my definition - doesn't behave like that
      • there is ValueList and ValueMap :)
    • Setty types: Set, Bag

Sigilless symbols:

• declared with \
  • disclaimer: among other things - note to self: needs a better name
• referenced without any prefix(=sigil)
• bound to the right handside
  • can be seen as alias when used with plain values

First runtime interactions:

• prompt subroutine

Installation:

• using rakubrew on Ubuntu, WSL
• major OS'es are supported
• please report issues you encounter

Calculations in the REPL:

• TODO: a show-off of some operators on numbers and strings
  • basic numeric operators
  • some method calls
  • ~, x
  • comparisons: at least numeric and textual