KCL
defines the following types and keywords the language.
All these types can be nested in various forms where nesting applies. Like arrays can hold objects and vice versa.
Constant declaration
Constants are defined with a name and a value, like so:
myBool = false
Currently you cannot redeclare a constant.
Objects
An object is defined with {}
braces. Here is an example object:
myObj = { a = 0, b = "thing" }
To get the property of an object, you can call myObj.a
, which in the above
example returns 0.
ImportedGeometry
Using import
you can import geometry defined using other CAD software. In KCL,
these objects have type ImportedGeometry
and can mostly be treated like any
other solid (they can be rotated, scaled, etc.), although there is no access to
their internal components. See the modules and imports docs for more
detail on importing geometry.
Tags
Tags are used to give a name (tag) to a specific path.
Tag declarations - TagDecl
The syntax for declaring a tag is $myTag
you would use it in the following
way:
startSketchOn(XZ)
|> startProfile(at = origin)
|> angledLine(angle = 0, length = 191.26, tag = $rectangleSegmentA001)
|> angledLine(
angle = segAng(rectangleSegmentA001) - 90,
length = 196.99,
tag = $rectangleSegmentB001,
)
|> angledLine(
angle = segAng(rectangleSegmentA001),
length = -segLen(rectangleSegmentA001),
tag = $rectangleSegmentC001,
)
|> line(endAbsolute = [profileStartX(%), profileStartY(%)])
|> close()
When a function requires declaring a new tag (using the $
syntax), the argument has type TagDecl
.
Tag identifiers
A tag created using a tag declarator can be used by writing its name without the $
, e.g., myTag
.
Where necessary to disambiguate from tag declarations, we call these tag identifiers.
In the example above we use the tag identifier rectangleSegmentA001
to get the angle of the segment
using segAng(rectangleSegmentA001)
.
Tags can identify either an edge or face of a solid, or a line or other edge of a sketch. Functions
which take a tag identifier as an argument will use either TaggedEdge
(for the edge of a
solid or sketch) or TaggedFace
.
If a line in a sketch is tagged and then the sketch is extruded, the tag is a TaggedEdge
before
extrusion and a TaggedFace
after extrusion.
START
and END
START
and END
are special tags
for identifying the starting and ending faces of an extruded solid.
Tag Scope
Tags are scoped globally if in the root context meaning in this example you can
use the tag rectangleSegmentA001
in any function or expression in the file.
However if the code was written like this:
fn rect(origin) {
return startSketchOn(XZ)
|> startProfile(at = origin)
|> angledLine(angle = 0, length = 191.26, tag = $rectangleSegmentA001)
|> angledLine(
angle = segAng(rectangleSegmentA001) - 90,
length = 196.99,
tag = $rectangleSegmentB001,
)
|> angledLine(
angle = segAng(rectangleSegmentA001),
length = -segLen(rectangleSegmentA001),
tag = $rectangleSegmentC001,
)
|> line(endAbsolute = [profileStartX(%), profileStartY(%)])
|> close()
}
rect(origin = [0, 0])
rect(origin = [20, 0])
Those tags would only be available in the rect
function and not globally.
However you likely want to use those tags somewhere outside the rect
function.
Tags are accessible through the sketch group they are declared in. For example the following code works.
fn rect(origin) {
return startSketchOn(XZ)
|> startProfile(at = origin)
|> angledLine(angle = 0, length = 191.26, tag = $rectangleSegmentA001)
|> angledLine(
angle = segAng(rectangleSegmentA001) - 90,
length = 196.99,
tag = $rectangleSegmentB001,
)
|> angledLine(
angle = segAng(rectangleSegmentA001),
length = -segLen(rectangleSegmentA001),
tag = $rectangleSegmentC001,
)
|> line(endAbsolute = [profileStartX(%), profileStartY(%)])
|> close()
}
rect(origin = [0, 0])
myRect = rect(origin = [20, 0])
myRect
|> extrude(length = 10)
|> fillet(radius = 0.5, tags = [myRect.tags.rectangleSegmentA001])
See how we use the tag rectangleSegmentA001
in the fillet
function outside
the rect
function. This is because the rect
function is returning the
sketch group that contains the tags.
If you find any issues using any of the above expressions or syntax,
please file an issue with the ast
label on the modeling-app
repo.