basic loops things needed

[jessfraz]

this is my mental notes so i can mess around later

• [0..10] in the parser should expand to [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]  #456
• for text in v { innershit } needs to parse
• if we have number one here then for num in [0..10] { innershit } should parse the same way
• get properties from objects like obj.thing where obj = {thing: 2}  #454
• get properties from arrays like array[0] where array = [0, 1, 2]  #455
• we need to collect the data into a ForLoopExpression type and add it to the ast like:

struct ForLoopExpression {
     // the source range start and end
     start: usize,
    end: usize,
     // The var we assign in each loop.
      variable: Identifier,
      // The array we are looping over.
     array: ArrayExpression,
     // This is the inner shit in the loop.
      body: Program,
}

• then we need the executor to loop over the array expression and re-execute the body changing the identifier value every time

something like that

added some failing tests here: f3589e0

[jessfraz]

Okay before diving in more I wanted to spec this out with a gear and I have something a little like this but I really dont like it

let res = 64
let gear_step = 2 * pi() / res
let half_gear_step = gear_step / 2.0
let gear_radius = 5.0
let gear_sprocket_radius = 6.0

fn getCoord = (r) => {
    let first = {x: gear_radius * sin(gear_step * r), y: gear_radius * cos(gear_step * r)}
    let second = {x: gear_sprocket_radius * sin(gear_step * r), y: gear_sprocket_radius * cos(gear_step * r)}

    return [first, second]
}

let startingCoords = getCoord(0)

let myGear = startSketchAt(startingCoords[0])

for r in [1..64] {
    let lastCoords = getCoord(r - 1)
    let coords = getCoord(r)
    if (n - 1) % 4 < 2 {
        myGear
            |> line([coords[1].x-lastCoords[0].x, coords[1].y-lastCoords[0].y], %)
    } else {
        myGear
            |> line([coords[0].x-lastCoords[1].x, coords[0].y-lastCoords[1].y], %)
    }
}

also requires if statements which we can do, and sin and cos in std lib also doable, and a CONST you can access called PI, also doable.

anyways the pipes get super weird and I bet @adamchalmers had better ideas here

but this is a good example to make work, as in the gear not my syntax

[franknoirot]

@jessfraz check out this issue in the KCL experimentation repo that @adamchalmers set up: KittyCAD/kcl-experiments#6

[jessfraz]

okay yeah I like @Irev-Dev example it seems like patterns, unless I'm hallucinating what patterns are but also like @adamchalmers as well

[jessfraz]

i like the loop in the pipe like @Irev-Dev has and patterns like that I guess my question is do we need a regular loop then? just like a for x in [] do we even need that?