adapted wire stubs with auto side detection

gallery/target_api.typ

@@ -14,24 +14,10 @@
     debug: (ports: true)
   )
   
-  element.block(
-    size: (1, 2),
-    ports: (
-      west: (("a", "A"), "e"),
-      north: "b",
-      east: "c",
-      south: "d"
-    ),
-    pos: (
-      (offset: -1, from: "PCBuf.south"),
-      2,//(align: "e", with: "PCBuf.EN"),
-    )
-  )
-  
-  /*
   wire.stub("PCBuf.CLK", name: "CLK")
   wire.stub("PCBuf.EN", name: "PCWrite")
   
+  /*
   element.multiplexer(
     pos: (
       3, (align: "in0", with: "PCBuf.PC")

src/util.typ

@@ -74,3 +74,14 @@
   "center", "north", "east", "west", "south",
   "north-east", "north-west", "south-east", "south-west"
 )
+
+#let get-port-side(element, port) = {
+  for (side, ports) in element.ports {
+    for p in ports {
+      if p.id == port {
+        return side
+      }
+    }
+  }
+  panic("Unknown port " + port + " on element " + element.id)
+}

src/wire.typ

@@ -1,5 +1,6 @@
 #import "@preview/cetz:0.3.2": draw, coordinate
-#import "util.typ": opposite-anchor
+#import "util.typ": opposite-anchor, get-port-side
+#import "elements/element.typ"
 
 /// List of valid wire styles
 /// #examples.wires
@@ -267,7 +268,28 @@
 /// - vertical (bool): Whether the name should be displayed vertically
 /// - length (number): The length of the stub
 /// - name-offset (number): The name offset, perpendicular to the stub
-#let stub(port-id, side, name: none, vertical: false, length: 1em, name-offset: 0) = {
+#let stub(anchor, name: none, vertical: false, length: 1em, name-offset: 0) = {
+  if "." not in anchor {
+    panic("`anchor` must be a valid anchor of an element")
+  }
+  let parts = anchor.split(".")
+  let port-id = parts.last()
+  let port-elmt-id = parts.slice(0, -1).join(".")
+
+  let pre-process = (elements, elmt) => {
+    let eid = elmt.id
+
+    if port-elmt-id not in elements {
+      panic("Unknown element " + port-elmt-id)
+    }
+    let port-elmt = elements.at(port-elmt-id)
+    let side = get-port-side(port-elmt, port-id)
+    elements.at(eid).insert("side", side)
+    return elements
+  }
+
+  let draw-func(elmt, bounds) = {
+    let side = elmt.side
     let end-offset = (
       north: (0, length),
       east: (length, 0),
@@ -282,9 +304,10 @@
       west: (-length, name-offset)
     ).at(side)
 
-  draw.line(
-    port-id,
-    (rel: end-offset, to: port-id)
+    let shapes = ()
+    shapes += draw.line(
+      anchor,
+      (rel: end-offset, to: anchor)
     )
     if name != none {
       let text-anchor = if vertical {
@@ -295,12 +318,20 @@
           "east": "north"
         ).at(side)
       } else { opposite-anchor(side) }
-    draw.content(
+      shapes += draw.content(
         anchor: text-anchor,
         padding: 0.2em,
         angle: if vertical {90deg} else {0deg},
-      (rel: name-offset, to: port-id),
+        (rel: name-offset, to: anchor),
         name
       )
     }
+
+    return (shapes, bounds)
+  }
+
+  return element.elmt(
+    draw-shape: draw-func,
+    pre-process: pre-process
+  )
 }