Release 0.2.1

Reviewed-on: #9

README.md

@@ -1,3 +1,150 @@
 # chronos
 
 A Typst package to draw sequence diagrams with CeTZ
+
+---
+
+This package lets you render sequence diagrams directly in Typst. The following boilerplate code creates an empty sequence diagram with two participants:
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#import "@preview/chronos:0.2.1"
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+})
+```
+
+</td>
+<td><img src="./gallery/readme/boilerplate.png"></td>
+</tr>
+</table>
+
+> *Disclaimer*\
+> The package cannot parse PlantUML syntax for the moment, and thus requires the use of element functions, as shown in the examples.
+> A PlantUML parser is in the TODO list, just not the top priority
+
+## Basic sequences
+
+You can make basic sequences using the `_seq` function:
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+
+  _seq("Alice", "Bob", comment: "Hello")
+  _seq("Bob", "Bob", comment: "Think")
+  _seq("Bob", "Alice", comment: "Hi")
+})
+```
+
+</td>
+<td><img src="./gallery/readme/simple_sequence.png"></td>
+</tr>
+</table>
+
+You can make lifelines using the following parameters of the `_seq` function:
+ - `enable-dst`: enables the destination lifeline
+ - `create-dst`: creates the destination lifeline and participant
+ - `disable-dst`: disables the destination lifeline
+ - `destroy-dst`: destroys the destination lifeline and participant
+ - `disable-src`: disables the source lifeline
+ - `destroy-src`: destroy the source lifeline and participant
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#chronos.diagram({
+  import chronos: *
+  _par("A", display-name: "Alice")
+  _par("B", display-name: "Bob")
+  _par("C", display-name: "Charlie")
+  _par("D", display-name: "Derek")
+
+  _seq("A", "B", comment: "hello", enable-dst: true)
+  _seq("B", "B", comment: "self call", enable-dst: true)
+  _seq("C", "B", comment: "hello from thread 2", enable-dst: true, lifeline-style: (fill: rgb("#005500")))
+  _seq("B", "D", comment: "create", create-dst: true)
+  _seq("B", "C", comment: "done in thread 2", disable-src: true, dashed: true)
+  _seq("B", "B", comment: "rc", disable-src: true, dashed: true)
+  _seq("B", "D", comment: "delete", destroy-dst: true)
+  _seq("B", "A", comment: "success", disable-src: true, dashed: true)
+})
+```
+
+</td>
+<td><img src="./gallery/readme/lifelines.png"></td>
+</tr>
+</table>
+
+## Showcase
+
+Several features have already been implemented in Chronos. Don't hesitate to checkout the examples in the [gallery](./gallery) folder to see what you can do. 
+
+#### Quick example reference:
+<table>
+<tr>
+<td><strong>Example</strong></td>
+<td><strong>Features</strong></td>
+</tr>
+<tr>
+<td>
+
+`example1` <br>([PDF](./gallery/example1.pdf)|[Typst](./gallery/example1.typ))
+
+</td>
+<td>Simple cases, color sequences, groups, separators, gaps, self-sequences</td>
+</tr>
+<tr>
+<td>
+
+`example2` <br>([PDF](./gallery/example2.pdf)|[Typst](./gallery/example2.typ))
+
+</td>
+<td>Lifelines, found/lost messages, synchronized sequences, slanted sequences</td>
+</tr>
+<tr>
+<td>
+
+`example3` <br>([PDF](./gallery/example3.pdf)|[Typst](./gallery/example3.typ))
+
+</td>
+<td>Participant shapes, sequence tips, hidden partipicant ends</td>
+</tr>
+<tr>
+<td>
+
+`notes` <br>([PDF](./gallery/notes.pdf)|[Typst](./gallery/notes.typ))
+
+</td>
+<td>Notes (duh), deferred participant creation</td>
+</tr>
+</table>
+
+> [!NOTE]
+> 
+> Many examples were taken/adapted from the PlantUML [documentation](https://plantuml.com/sequence-diagram) on sequence diagrams

TODO.md

@@ -0,0 +1,28 @@
+# TODO
+
+- [x] Basic participants
+- [x] Basic sequences
+- [x] Separators
+- [x] Gaps
+- [x] Groups
+- [x] Self arrows
+- [x] Arrow from start / to end, small arrows
+- [x] Lifelines
+- [x] Different types of participants
+- [x] Notes
+- [x] Synchronized arrows
+- [x] Slanted arrows
+- [x] Different types of arrow tips
+- [x] Sequence comment alignment
+- [x] Fix group size with syncs
+- [ ] Fix column spacing with notes over multiple columns
+- [ ] Fix notes with arrows from start / to end / small arrows
+- [ ] Fix group size with self arrows + notes
+- [ ] Unify styling structure
+- [ ] Add args verification to catch user errors + pretty error messages
+- [ ] PlantUML parser
+- [ ] (Message numbering)
+- [ ] Mainframes
+- [x] Different types of groups (alt/loop/etc.)
+- [ ] Delays
+- [ ] Auto-fit in parent

docs/example.typ

@@ -0,0 +1,39 @@
+#import "../src/lib.typ" as chronos
+
+#let example-preamble = "import \"../src/lib.typ\": *;"
+#let example-scope = (
+  chronos: chronos
+)
+
+#let example(src, show-src: true, vertical: false, fill: false, wrap: true) = {
+  src = src.text
+  let full-src = example-preamble + src
+  let body = eval(full-src, scope: example-scope)
+  let img = if wrap { chronos.diagram(body) } else { body }
+
+  block(width: 100%,
+    align(center,
+      box(
+        stroke: black + 1pt,
+        radius: .5em,
+        fill: if fill {color.white.darken(2%)} else {none},
+        if show-src {
+          let src-block = raw(src, block: true, lang: "typc")
+          table(
+            columns: if vertical {1} else {2},
+            inset: 5pt,
+            align: horizon + center,
+            stroke: none,
+            table.cell(inset: 1em, img),
+            if vertical {table.hline()} else {table.vline()}, src-block
+          )
+        } else {
+          table(
+            inset: 1em,
+            img
+          )
+        }
+      )
+    )
+  )
+}

docs/examples.typ

@@ -0,0 +1,213 @@
+#import "example.typ": example
+
+#let seq-return = example(```
+_seq(
+  "Bob", "Alice",
+  comment: [hello],
+  enable-dst: true
+)
+_seq(
+  "Alice", "Alice",
+  comment: [some action]
+)
+_ret(comment: [bye])
+```)
+
+#let seq-comm-align = example(```
+_par("p1",
+     display-name: "Start participant")
+_par("p2",
+     display-name: "End participant")
+let alignments = (
+  "start", "end",
+  "left", "right",
+  "center"
+)
+for a in alignments {
+  _seq(
+    "p2", "p1",
+    comment: raw(a),
+    comment-align: a
+  )
+}
+```)
+
+#let seq-tips = example(```
+let _seq = _seq.with(comment-align: "center")
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_seq("a", "b", comment: "Various tips", end-tip: "")
+_seq("a", "b", end-tip: ">", comment: `->`)
+_seq("a", "b", end-tip: ">>", comment: `->>`)
+_seq("a", "b", end-tip: "\\", comment: `-\`)
+_seq("a", "b", end-tip: "\\\\", comment: `-\\`)
+_seq("a", "b", end-tip: "/", comment: `-/`)
+_seq("a", "b", end-tip: "//", comment: `-//`)
+_seq("a", "b", end-tip: "x", comment: `->x`)
+_seq("a", "b", start-tip: "x", comment: `x->`)
+_seq("a", "b", start-tip: "o", comment: `o->`)
+_seq("a", "b", end-tip: ("o", ">"), comment: `->o`)
+_seq("a", "b", start-tip: "o",
+               end-tip: ("o", ">"), comment: `o->o`)
+_seq("a", "b", start-tip: ">",
+               end-tip: ">", comment: `<->`)
+_seq("a", "b", start-tip: ("o", ">"),
+               end-tip: ("o", ">"), comment: `o<->o`)
+_seq("a", "b", start-tip: "x",
+               end-tip: "x", comment: `x<->x`)
+_seq("a", "b", end-tip: ("o", ">>"), comment: `->>o`)
+_seq("a", "b", end-tip: ("o", "\\"), comment: `-\o`)
+_seq("a", "b", end-tip: ("o", "\\\\"), comment: `-\\o`)
+_seq("a", "b", end-tip: ("o", "/"), comment: `-/o`)
+_seq("a", "b", end-tip: ("o", "//"), comment: `-//o`)
+_seq("a", "b", start-tip: "x",
+               end-tip: ("o", ">"), comment: `x->o`)
+```)
+
+#let grp = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_grp("Group 1", desc: "Description", {
+  _seq("a", "b", comment: "Authentication")
+  _grp("loop", desc: "1000 times", {
+    _seq("a", "b", comment: "DoS Attack")
+  })
+  _seq("a", "b", end-tip: "x")
+})
+```)
+
+#let alt = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_alt(
+  "first encounter", {
+    _seq("a", "b", comment: "Who are you ?")
+    _seq("b", "a", comment: "I'm Bob")
+  },
+
+  "know eachother", {
+    _seq("a", "b", comment: "Hello Bob")
+    _seq("b", "a", comment: "Hello Alice")
+  },
+
+  "best friends", {
+    _seq("a", "b", comment: "Hi !")
+    _seq("b", "a", comment: "Hi !")
+  }
+)
+```)
+
+#let loop = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_loop("default loop", {
+  _seq("a", "b", comment: "Are you here?")
+})
+_gap()
+_loop("min loop", min: 1, {
+  _seq("a", "b", comment: "Are you here?")
+})
+_gap()
+_loop("min-max loop", min: 1, max: 5, {
+  _seq("a", "b", comment: "Are you still here?")
+})
+```)
+
+#let sync = example(```
+_par("alice", display-name: "Alice")
+_par("bob", display-name: "Bob")
+_par("craig", display-name: "Craig")
+
+_seq("bob", "alice")  // Unsynchronized
+_seq("bob", "craig")  //  "
+_sync({
+  _seq("bob", "alice")  // Synchronized
+  _seq("bob", "craig")  //  "
+})
+_seq("alice", "bob")  // Unsynchronized
+_seq("craig", "bob")  //  "
+_sync({
+  _seq("alice", "bob")  // Synchronized
+  _seq("craig", "bob")  //  "
+})
+```)
+
+#let gaps = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_seq("a", "b", comment: [message 1])
+_seq("b", "a", comment: [ok], dashed: true)
+_gap()
+_seq("a", "b", comment: [message 2])
+_seq("b", "a", comment: [ok], dashed: true)
+_gap(size: 40)
+_seq("a", "b", comment: [message 3])
+_seq("b", "a", comment: [ok], dashed: true)
+```)
+
+#let seps = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_sep[Initialization]
+_seq("a", "b", comment: [Request 1])
+_seq(
+  "b", "a",
+  comment: [Response 1],
+  dashed: true
+)
+
+_sep[Repetition]
+_seq("a", "b", comment: [Request 2])
+_seq(
+  "b", "a",
+  comment: [Response 2],
+  dashed: true
+)
+```)
+
+#let delays = example(```
+_par("a", display-name: "Alice")
+_par("b", display-name: "Bob")
+
+_seq("a", "b", comment: [Auth Request])
+_delay()
+_seq(
+  "b", "a",
+  comment: [Auth Response],
+  dashed: true
+)
+_delay(name: [5 minutes later])
+_seq(
+  "b", "a",
+  comment: [Good Bye !],
+  dashed: true
+)
+```)
+
+#let notes-shapes = example(```
+_par("alice", display-name: "Alice")
+_par("bob", display-name: "Bob")
+_note("over", `default`, pos: "alice")
+_note("over", `rect`, pos: "bob", shape: "rect")
+_note("over", `hex`, pos: ("alice", "bob"), shape: "hex")
+```)
+
+#let notes-sides = example(```
+_par("alice", display-name: "Alice")
+_par("bob", display-name: "Bob")
+_par("charlie", display-name: "Charlie")
+_note("left", [`left` of Alice], pos: "alice")
+_note("right", [`right` of Charlie], pos: "charlie")
+_note("over", [`over` Alice and Bob], pos: ("alice", "bob"))
+_note("across", [`across` all participants])
+_seq("alice", "bob")
+_note("left", [linked with sequence])
+_note("over", [A note], pos: "alice")
+_note("over", [Aligned note], pos: "charlie", aligned: true)
+```, vertical: true)

docs/gaps_seps.typ

@@ -0,0 +1,15 @@
+/// Creates a separator before the next element
+/// #examples.seps
+/// - name (content): Name to display in the middle of the separator
+#let _sep(name) = {}
+
+/// Creates a delay before the next element
+/// #examples.delays
+/// - name (content, none): Name to display in the middle of the delay area
+/// - size (int): Size of the delay
+#let _delay(name: none, size: 30) = {}
+
+/// Creates a gap before the next element
+/// #examples.gaps
+/// - size (int): Size of the gap
+#let _gap(size: 20) = {}

docs/groups.typ

@@ -0,0 +1,58 @@
+/// Creates a group of sequences
+/// #examples.grp
+/// - name (content): The group's name
+/// - desc (none, content): Optional description
+/// - type (str): The groups's type (should only be set through other functions like @@_alt() or @@_loop() )
+/// - elmts (array): Elements inside the group (can be sequences, other groups, notes, etc.)
+#let _grp(
+  name,
+  desc: none,
+  type: "default",
+  elmts
+) = {}
+
+/// Creates an alt-else group of sequences
+/// 
+/// It contains at least one section but can have as many as needed
+/// #examples.alt
+/// - desc (content): The alt's label
+/// - elmts (array): Elements inside the alt's first section
+/// - ..args (content, array): Complementary "else" sections.\ You can add as many else sections as you need by passing a content (else section label) followed by an array of elements (see example)
+#let _alt(
+  desc,
+  elmts,
+  ..args
+)
+
+/// Creates a looped group of sequences
+/// #examples.loop
+/// - desc (content): Loop description
+/// - min (none, number): Optional lower bound of the loop
+/// - max (auto, number): Upper bound of the loop. If left as `auto` and `min` is set, it will be infinity (`'*'`)
+/// - elmts (array): Elements inside the group
+#let _loop(
+  desc,
+  min: none,
+  max: auto,
+  elmts
+) = {}
+
+/// Synchronizes multiple sequences\
+/// All elements inside a synchronized group will start at the same time
+/// #examples.sync
+/// - elmts (array): Synchronized elements (generally sequences or notes)
+#let _sync(
+  elmts
+)
+
+/// Creates an optional group\
+/// This is a simple wrapper around @@_grp()
+/// - desc (content): Group description
+/// - elmts (array): Elements inside the group
+#let _opt(desc, elmts) = {}
+
+/// Creates a break group\
+/// This is a simple wrapper around @@_grp()
+/// - desc (content): Group description
+/// - elmts (array): Elements inside the group
+#let _break(desc, elmts) = {}

docs/notes.typ

@@ -0,0 +1,23 @@
+/// Creates a note
+/// - side (str): The side on which to place the note (see @@SIDES for accepted values)
+/// - content (content): The note's content
+/// - pos (none, str, array): Optional participant(s) on which to draw next to / over. If `side` is "left" or "right", sets next to which participant the note is placed. If `side` is "over", sets over which participant(s) it is placed
+/// - color (color): The note's color
+/// - shape (str): The note's shape (see @@SHAPES for accepted values)
+/// - aligned (bool): True if the note is aligned with another note, in which case `side` must be `"over"`, false otherwise
+#let _note(
+  side,
+  content,
+  pos: none,
+  color: rgb("#FEFFDD"),
+  shape: "default",
+  aligned: false
+) = {}
+
+/// Accepted values for `shape` argument of @@_note()
+/// #examples.notes-shapes
+#let SHAPES = ("default", "rect", "hex")
+
+/// Accepted values for `side` argument of @@_note()
+/// #examples.notes-sides
+#let SIDES = ("left", "right", "over", "across")

docs/participants.typ

@@ -0,0 +1,69 @@
+/// Possible participant shapes
+/// #box(width: 100%, align(center)[
+///   #chronos.diagram({
+///     import chronos: *
+///     let _par = _par.with(show-bottom: false)
+///     _par("Foo", display-name: "participant", shape: "participant")
+///     _par("Foo1", display-name: "actor", shape: "actor")
+///     _par("Foo2", display-name: "boundary", shape: "boundary")
+///     _par("Foo3", display-name: "control", shape: "control")
+///     _par("Foo4", display-name: "entity", shape: "entity")
+///     _par("Foo5", display-name: "database", shape: "database")
+///     _par("Foo6", display-name: "collections", shape: "collections")
+///     _par("Foo7", display-name: "queue", shape: "queue")
+///     _par("Foo8", display-name: "custom", shape: "custom", custom-image: TYPST)
+///     _gap()
+///   })
+/// ])
+#let SHAPES = (
+  "participant",
+  "actor",
+  "boundary",
+  "control",
+  "entity",
+  "database",
+  "collections",
+  "queue",
+  "custom"
+)
+
+/// Creates a new participant
+/// - name (str): Unique participant name used as reference in other functions
+/// - display-name (auto, content): Name to display in the diagram. If set to `auto`, `name` is used
+/// - from-start (bool): If set to true, the participant is created at the top of the diagram. Otherwise, it is created at the first reference
+/// - invisible (bool): If set to true, the participant will not be shown
+/// - shape (str): The shape of the participant. Possible values in @@SHAPES
+/// - color (color): The participant's color
+/// - custom-image (none, image): If shape is 'custom', sets the custom image to display
+/// - show-bottom (bool): Whether to display the bottom shape
+/// - show-top (bool): Whether to display the top shape
+/// -> array
+#let _par(
+  name,
+  display-name: auto,
+  from-start: true,
+  invisible: false,
+  shape: "participant",
+  color: rgb("#E2E2F0"),
+  custom-image: none,
+  show-bottom: true,
+  show-top: true,
+) = {}
+
+/// Sets some options for columns between participants
+///
+/// Parameters `p1` and `p2` MUST be consecutive participants (also counting found/lost messages), but they do not need to be in the left to right order
+/// - p1 (str): The first neighbouring participant
+/// - p2 (str): The second neighbouring participant
+/// - width (auto, int, float, length): Optional fixed width of the column\ If the column's content (e.g. sequence comments) is larger, it will overflow
+/// - margin (int, float, length): Additional margin to add to the column\ This margin is not included in `width` and `min-width`, but rather added separately
+/// - min-width (int, float, length): Minimum width of the column\ If set to a larger value than `width`, the latter will be overriden
+/// - max-width (int, float, length, none): Maximum width of the column\ If set to a lower value than `width`, the latter will be overriden\ If set to `none`, no restriction is applied
+#let _col(
+  p1,
+  p2,
+  width: auto,
+  margin: 0,
+  min-width: 0,
+  max-width: none
+) = {}

docs/sequences.typ

@@ -0,0 +1,65 @@
+/// Manually adds an event to the given participant
+/// - participant (str): The participant concerned by the event
+/// - event (str): The event type (see @@EVENTS for ccepted values)
+#let _evt(participant, event) = {}
+
+/// Creates a sequence / message between two participants
+/// - p1 (str): Start participant
+/// - p2 (str): End participant
+/// - comment (none, content): Optional comment to display along the arrow
+/// - comment-align (str): Where to align the comment with respect to the arrow (see @@comment-align for accepted values)
+/// - dashed (bool): Whether the arrow's stroke is dashed or not
+/// - start-tip (str): Start arrow tip (see @@tips for accepted values)
+/// - end-tip (str): End arrow tip (see @@tips for accepted values)
+/// - color (color): Arrow's color
+/// - flip (bool): If true, the arrow is flipped (goes from end to start). This is particularly useful for self calls, to change the side on which the arrow appears
+/// - enable-dst (bool): If true, enables the destination lifeline
+/// - create-dst (bool): If true, creates the destination lifeline and participant
+/// - disable-dst (bool): If true, disables the destination lifeline
+/// - destroy-dst (bool): If true, destroys the destination lifeline and participant
+/// - disable-src (bool): If true, disables the source lifeline
+/// - destroy-src (bool): If true, destroy the source lifeline and participant
+/// - lifeline-style (auto, dict): Optional styling options for lifeline rectangles (see CeTZ documentation for more information on all possible values)
+/// - slant (none, int): Optional slant of the arrow
+/// -> array
+#let _seq(
+  p1,
+  p2,
+  comment: none,
+  comment-align: "left",
+  dashed: false,
+  start-tip: "",
+  end-tip: ">",
+  color: black,
+  flip: false,
+  enable-dst: false,
+  create-dst: false,
+  disable-dst: false,
+  destroy-dst: false,
+  disable-src: false,
+  destroy-src: false,
+  lifeline-style: auto,
+  slant: none
+) = {}
+
+/// Creates a return sequence
+/// #examples.seq-return
+/// - comment (none, content): Optional comment to display along the arrow
+#let _ret(comment: none) = {}
+
+/// Accepted values for `comment-align` argument of @@_seq()
+/// #examples.seq-comm-align
+#let comment-align = (
+  "start", "end", "left", "center", "right"
+)
+
+/// Accepted values for `event` argument of @@_evt()
+/// 
+/// `EVENTS = ("create", "destroy", "enable", "disable")`
+#let EVENTS = ("create", "destroy", "enable", "disable")
+
+/// Accepted values for `start-tip` and `end-tip` arguments of @@_seq()
+/// #examples.seq-tips
+#let tips = (
+  "", ">", ">>", "\\", "\\\\", "/", "//", "x", "o",
+)

gallery/example1.typ

@@ -33,15 +33,38 @@ Alice <-- Bob: Another authentication Response
 #chronos.diagram({
   import chronos: *
   _seq("Alice", "Bob", comment: "Authentication Request")
+
+  _alt(
+    "successful case", {
+      _seq("Bob", "Alice", comment: "Authentication Accepted")
+    },
+    "some kind of failure", {
       _seq("Bob", "Alice", comment: "Authentication Failure")
 
       _grp("My own label", desc: "My own label2", {
         _seq("Alice", "Log", comment: "Log attack start")
-    _grp("loop", desc: "1000 times", {
+        _loop("1000 times", {
           _seq("Alice", "Bob", comment: "DNS Attack")
         })
-    _seq("Alice", "Bob", comment: "Log attack end")
+        _seq("Alice", "Log", comment: "Log attack end")
       })
+    },
+    "Another type of failure", {
+      _seq("Bob", "Alice", comment: "Please repeat")
+    }
+  )
+})
+
+#chronos.diagram({
+  import chronos: *
+  _par("a", display-name: box(width: 1.5em, height: .5em), show-bottom: false)
+  _par("b", display-name: box(width: 1.5em, height: .5em), show-bottom: false)
+  _col("a", "b", width: 2cm)
+  _loop("a<1", min: 1, {
+    _seq("a", "b", end-tip: ">>")
+    _seq("b", "a", end-tip: ">>")
+  })
+  _seq("a", "b", end-tip: ">>")
 })
 
 #chronos.diagram({
@@ -55,6 +78,15 @@ Alice <-- Bob: Another authentication Response
   _seq("Bob", "Alice", comment: "another authentication Response", dashed: true)
 })
 
+#chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Bob", comment: "Authentication Request")
+  _delay()
+  _seq("Bob", "Alice", comment: "Authentication Response")
+  _delay(name: "5 minutes later")
+  _seq("Bob", "Alice", comment: "Good Bye !")
+})
+
 #chronos.diagram({
   import chronos: *
   _seq("Alice", "Bob", comment: "message 1")

gallery/example2.typ

@@ -49,3 +49,121 @@
   _seq("Alice", "?", comment: [->?\ *short* from actor1])
   _seq("Alice", "Bob", comment: [->\ from actor1 to actor2])
 })
+
+#chronos.diagram({
+  import chronos: *
+  _par("alice", display-name: "Alice")
+  _par("bob", display-name: "Bob")
+  _par("craig", display-name: "Craig")
+
+  _seq("bob", "alice")
+  _seq("bob", "craig")
+  _gap()
+  
+  _sync({
+    _seq("bob", "alice", comment: "Synched", comment-align: "start")
+    _seq("bob", "craig", comment: "Synched", comment-align: "start")
+  })
+  _gap()
+  
+  _seq("alice", "bob")
+  _seq("craig", "bob")
+  _gap()
+  
+  _sync({
+    _seq("alice", "bob")
+    _seq("craig", "bob")
+  })
+  _gap()
+  
+  _sync({
+    _seq("alice", "bob", enable-dst: true)
+    _seq("craig", "bob")
+  })
+  _gap()
+
+  _evt("bob", "disable")
+})
+
+#chronos.diagram({
+  import chronos: *
+  _par("alice", display-name: "Alice")
+  _par("bob", display-name: "Bob")
+  _par("craig", display-name: "Craig")
+
+  _seq("alice", "bob")
+  _seq("bob", "craig", slant: auto)
+  _seq("alice", "craig", slant: 20)
+
+  _sync({
+    _seq("alice", "bob", slant: 10)
+    _seq("craig", "bob", slant: 20)
+  })
+
+  _sync({
+    _seq("alice", "bob", slant: auto)
+    _seq("bob", "alice", slant: auto)
+  })
+
+  _gap()
+  _evt("bob", "disable")
+})
+
+#grid(columns: 2, column-gutter: 2em,
+  chronos.diagram({
+    import chronos: *
+
+    _par("alice", display-name: "Alice")
+    _par("bob", display-name: "Bob")
+    _seq("alice", "bob", comment: "This is a very long comment")
+
+    // Left to right
+    _seq("alice", "bob", comment: "Start aligned", comment-align: "start")
+    _seq("alice", "bob", comment: "End aligned", comment-align: "end")
+    _seq("alice", "bob", comment: "Left aligned", comment-align: "left")
+    _seq("alice", "bob", comment: "Right aligned", comment-align: "right")
+    _seq("alice", "bob", comment: "Centered", comment-align: "center")
+    _gap()
+
+    // Right to left
+    _seq("bob", "alice", comment: "Start aligned", comment-align: "start")
+    _seq("bob", "alice", comment: "End aligned", comment-align: "end")
+    _seq("bob", "alice", comment: "Left aligned", comment-align: "left")
+    _seq("bob", "alice", comment: "Right aligned", comment-align: "right")
+    _seq("bob", "alice", comment: "Centered", comment-align: "center")
+    _gap()
+
+    // Slant left to right
+    _seq("alice", "bob", comment: "Start aligned", comment-align: "start", slant: 10)
+    _seq("alice", "bob", comment: "End aligned", comment-align: "end", slant: 10)
+    _seq("alice", "bob", comment: "Left aligned", comment-align: "left", slant: 10)
+    _seq("alice", "bob", comment: "Right aligned", comment-align: "right", slant: 10)
+    _seq("alice", "bob", comment: "Centered", comment-align: "center", slant: 10)
+    _gap()
+
+    // Slant right to left
+    _seq("bob", "alice", comment: "Start aligned", comment-align: "start", slant: 10)
+    _seq("bob", "alice", comment: "End aligned", comment-align: "end", slant: 10)
+    _seq("bob", "alice", comment: "Left aligned", comment-align: "left", slant: 10)
+    _seq("bob", "alice", comment: "Right aligned", comment-align: "right", slant: 10)
+    _seq("bob", "alice", comment: "Centered", comment-align: "center", slant: 10)
+  }),
+
+  chronos.diagram({
+    import chronos: *
+
+    _par("alice", display-name: "Alice")
+
+    _seq("alice", "alice", comment: "Start aligned", comment-align: "start")
+    _seq("alice", "alice", comment: "End aligned", comment-align: "end")
+    _seq("alice", "alice", comment: "Left aligned", comment-align: "left")
+    _seq("alice", "alice", comment: "Right aligned", comment-align: "right")
+    _seq("alice", "alice", comment: "Centered", comment-align: "center")
+
+    _seq("alice", "alice", comment: "Start aligned", comment-align: "start", flip: true)
+    _seq("alice", "alice", comment: "End aligned", comment-align: "end", flip: true)
+    _seq("alice", "alice", comment: "Left aligned", comment-align: "left", flip: true)
+    _seq("alice", "alice", comment: "Right aligned", comment-align: "right", flip: true)
+    _seq("alice", "alice", comment: "Centered", comment-align: "center", flip: true)
+  })
+)

gallery/example3.typ

@@ -0,0 +1,166 @@
+#import "/src/lib.typ" as chronos
+
+#set page(width: auto, height: auto)
+
+#let TYPST = image("typst.png", width: 1.5cm, height: 1.5cm, fit: "contain")
+#let FERRIS = image("ferris.png", width: 1.5cm, height: 1.5cm, fit: "contain")
+#let ME = image("me.jpg", width: 1.5cm, height: 1.5cm, fit: "contain")
+
+#chronos.diagram({
+  import chronos: *
+  _par("Foo", display-name: "Participant", shape: "participant")
+  _par("Foo1", display-name: "Actor", shape: "actor")
+  _par("Foo2", display-name: "Boundary", shape: "boundary")
+  _par("Foo3", display-name: "Control", shape: "control")
+  _par("Foo4", display-name: "Entity", shape: "entity")
+  _par("Foo5", display-name: "Database", shape: "database")
+  _par("Foo6", display-name: "Collections", shape: "collections")
+  _par("Foo7", display-name: "Queue", shape: "queue")
+  _par("Foo8", display-name: "Typst", shape: "custom", custom-image: TYPST)
+  _par("Foo9", display-name: "Ferris", shape: "custom", custom-image: FERRIS)
+  _par("Foo10", display-name: "Baryhobal", shape: "custom", custom-image: ME)
+
+  _seq("Foo", "Foo1", comment: "To actor")
+  _seq("Foo", "Foo2", comment: "To boundary")
+  _seq("Foo", "Foo3", comment: "To control")
+  _seq("Foo", "Foo4", comment: "To entity")
+  _seq("Foo", "Foo5", comment: "To database")
+  _seq("Foo", "Foo6", comment: "To collections")
+  _seq("Foo", "Foo7", comment: "To queue")
+  _seq("Foo", "Foo8", comment: "To Typst")
+  _seq("Foo", "Foo9", comment: "To ferris")
+  _seq("Foo", "Foo10", comment: "To Baryhobal")
+})
+
+#pagebreak()
+#chronos.diagram({
+  import chronos: *
+  _par("me", display-name: "Me", shape: "custom", custom-image: ME)
+  _par("typst", display-name: "Typst", shape: "custom", custom-image: TYPST)
+  _par("rust", display-name: "Rust", shape: "custom", custom-image: FERRIS)
+
+  _seq("me", "typst", comment: "opens document", enable-dst: true)
+  _seq("me", "typst", comment: "types document")
+  _seq("typst", "rust", comment: "compiles content", enable-dst: true)
+  _seq("rust", "typst", comment: "renders document", disable-src: true)
+  _seq("typst", "me", comment: "displays document")
+  _evt("typst", "disable")
+})
+
+#pagebreak()
+
+#stack(dir: ltr, spacing: 1em,
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "b", end-tip: ">", comment: `->`)
+  _seq("a", "b", end-tip: ">>", comment: `->>`)
+  _seq("a", "b", end-tip: "\\", comment: `-\`)
+  _seq("a", "b", end-tip: "\\\\", comment: `-\\`)
+  _seq("a", "b", end-tip: "/", comment: `-/`)
+  _seq("a", "b", end-tip: "//", comment: `-//`)
+  _seq("a", "b", end-tip: "x", comment: `->x`)
+  _seq("a", "b", start-tip: "x", comment: `x->`)
+  _seq("a", "b", start-tip: "o", comment: `o->`)
+  _seq("a", "b", end-tip: ("o", ">"), comment: `->o`)
+  _seq("a", "b", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("a", "b", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("a", "b", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("a", "b", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("a", "b", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("a", "b", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("a", "b", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("a", "b", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("a", "b", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("a", "b", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+}),
+
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("b", "a", end-tip: ">", comment: `->`)
+  _seq("b", "a", end-tip: ">>", comment: `->>`)
+  _seq("b", "a", end-tip: "\\", comment: `-\`)
+  _seq("b", "a", end-tip: "\\\\", comment: `-\\`)
+  _seq("b", "a", end-tip: "/", comment: `-/`)
+  _seq("b", "a", end-tip: "//", comment: `-//`)
+  _seq("b", "a", end-tip: "x", comment: `->x`)
+  _seq("b", "a", start-tip: "x", comment: `x->`)
+  _seq("b", "a", start-tip: "o", comment: `o->`)
+  _seq("b", "a", end-tip: ("o", ">"), comment: `->o`)
+  _seq("b", "a", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("b", "a", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("b", "a", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("b", "a", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("b", "a", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("b", "a", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("b", "a", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("b", "a", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("b", "a", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("b", "a", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+}),
+
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "a", end-tip: ">", comment: `->`)
+  _seq("a", "a", end-tip: ">>", comment: `->>`)
+  _seq("a", "a", end-tip: "\\", comment: `-\`)
+  _seq("a", "a", end-tip: "\\\\", comment: `-\\`)
+  _seq("a", "a", end-tip: "/", comment: `-/`)
+  _seq("a", "a", end-tip: "//", comment: `-//`)
+  _seq("a", "a", end-tip: "x", comment: `->x`)
+  _seq("a", "a", start-tip: "x", comment: `x->`)
+  _seq("a", "a", start-tip: "o", comment: `o->`)
+  _seq("a", "a", end-tip: ("o", ">"), comment: `->o`)
+  _seq("a", "a", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("a", "a", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("a", "a", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("a", "a", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("a", "a", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("a", "a", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("a", "a", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("a", "a", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("a", "a", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("a", "a", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+})
+)
+
+#chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob", show-bottom: false)
+  _par("c", display-name: "Caleb", show-top: false)
+  _par("d", display-name: "Danny", show-bottom: false, show-top: false)
+
+  _gap()
+})
+
+#chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+  _par("c", display-name: "Caleb")
+  _par("d", display-name: "Danny")
+  _par("e", display-name: "Erika")
+
+  _col("a", "b")
+  _col("b", "c", width: 2cm)
+  _col("c", "d", margin: .5cm)
+  _col("d", "e", min-width: 2cm)
+
+  //_seq("b", "c", comment: [Hello World !])
+  //_seq("c", "d", comment: [Hello World])
+  //_seq("d", "e", comment: [Hello World])
+})

gallery/notes.typ

@@ -0,0 +1,145 @@
+#import "/src/lib.typ" as chronos: *
+
+#set page(width: auto, height: auto)
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "b", comment: [hello])
+  _note("left", [this is a first note])
+
+  _seq("b", "a", comment: [ok])
+  _note("right", [this is another note])
+
+  _seq("b", "b", comment: [I am thinking])
+  _note("left", [a note\ can also be defined\ on several lines])
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _note("left", [This is displayed\ left of Alice.], pos: "a", color: rgb("#00FFFF"))
+  _note("right", [This is displayed right of Alice.], pos: "a")
+  _note("over", [This is displayed over Alice.], pos: "a")
+  _note("over", [This is displayed\ over Bob and Alice.], pos: ("a", "b"), color: rgb("#FFAAAA"))
+  _note("over", [This is yet another\ example of\ a long note.], pos: ("a", "b"))
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("caller")
+  _par("server")
+
+  _seq("caller", "server", comment: [conReq])
+  _note("over", [idle], pos: "caller", shape: "hex")
+  _seq("server", "caller", comment: [conConf])
+  _note("over", ["r" as rectangle\ "h" as hexagon], pos: "server", shape: "rect")
+  _note("over", [this is\ on several\ lines], pos: "server", shape: "rect")
+  _note("over", [this is\ on several\ lines], pos: "caller", shape: "hex")
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+  _par("c", display-name: "Charlie")
+
+  _seq("a", "b", comment: [m1])
+  _seq("b", "c", comment: [m2])
+
+  _note("over", [Old method for note over all part. with:\ `note over FirstPart, LastPart`.], pos: ("a", "c"))
+  _note("across", [New method with:\ `note across`.])
+
+  _seq("b", "a")
+
+  _note("across", [Note across all part.], shape: "hex")
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _note("over", [initial state of Alice], pos: "a")
+  _note("over", [initial state of Bob], pos: "b")
+  _seq("b", "a", comment: [hello])
+})
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+  _par("c", display-name: "Charlie")
+  _par("d", display-name: "Donald")
+  _par("e", display-name: "Eddie")
+
+  _note("over", [initial state of Alice], pos: "a")
+  _note("over", [initial state of Bob the builder], pos: "b", aligned: true)
+
+  _note("over", [Note 1], pos: "a")
+  _note("over", [Note 2], pos: "b", aligned: true)
+  _note("over", [Note 3], pos: "c", aligned: true)
+
+  _seq("a", "d")
+  _note("over", [this is an extremely long note], pos: ("d", "e"))
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: [Alice])
+  _par("b", display-name: [The *Famous* Bob])
+
+  _seq("a", "b", comment: [hello #strike([there])])
+
+  _gap()
+  _seq("b", "a", comment: [ok])
+  _note("left", [
+    This is *bold*\
+    This is _italics_\
+    This is `monospaced`\
+    This is #strike([stroked])\
+    This is #underline([underlined])\
+    This is #underline([waved])\
+  ])
+
+  _seq("a", "b", comment: [A _well formatted_ message])
+  _note("right", [
+    This is #box(text([displayed], size: 18pt), fill: rgb("#5F9EA0"))\
+    #underline([left of]) Alice.
+  ], pos: "a")
+  _note("left", [
+    #underline([This], stroke: red) is #text([displayed], fill: rgb("#118888"))\
+    *#text([left of], fill: rgb("#800080")) #strike([Alice], stroke: red) Bob.*
+  ], pos: "b")
+  _note("over", [
+    #underline([This is hosted], stroke: rgb("#FF33FF")) by #box(baseline: 50%, image("gitea.png", width: 1cm, height: 1cm, fit: "contain"))
+  ], pos: ("a", "b"))
+})
+
+// TODO
+/*
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: [Alice])
+  _par("b", display-name: [Bob])
+
+  _seq("a", "b", comment: [Hello])
+  _note("left", [This is a note])
+
+  _seq("[", "a", comment: [Test])
+  _note("left", [This is also a note])
+})*/
+
+#pagebreak()
+
+#chronos.diagram({
+  _seq("Bob", "Alice", comment: [Hello])
+  _evt("Other", "create")
+})

gallery/readme/boilerplate.typ

@@ -0,0 +1,13 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+})

gallery/readme/lifelines.typ

@@ -0,0 +1,24 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("A", display-name: "Alice")
+  _par("B", display-name: "Bob")
+  _par("C", display-name: "Charlie")
+  _par("D", display-name: "Derek")
+
+  _seq("A", "B", comment: "hello", enable-dst: true)
+  _seq("B", "B", comment: "self call", enable-dst: true)
+  _seq("C", "B", comment: "hello from thread 2", enable-dst: true, lifeline-style: (fill: rgb("#005500")))
+  _seq("B", "D", comment: "create", create-dst: true)
+  _seq("B", "C", comment: "done in thread 2", disable-src: true, dashed: true)
+  _seq("B", "B", comment: "rc", disable-src: true, dashed: true)
+  _seq("B", "D", comment: "delete", destroy-dst: true)
+  _seq("B", "A", comment: "success", disable-src: true, dashed: true)
+})

gallery/readme/simple_sequence.typ

@@ -0,0 +1,17 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+
+  _seq("Alice", "Bob", comment: "Hello")
+  _seq("Bob", "Bob", comment: "Think")
+  _seq("Bob", "Alice", comment: "Hi")
+})

justfile

@@ -0,0 +1,12 @@
+# Local Variables:
+# mode: makefile
+# End:
+gallery_dir := "./gallery"
+set shell := ["bash", "-uc"]
+
+manual:
+  typst c manual.typ manual.pdf
+
+gallery:
+  for f in "{{gallery_dir}}"/*.typ; do typst c --root . "$f" "${f%typ}pdf"; done
+  for f in "{{gallery_dir}}"/readme/*.typ; do typst c --root . "$f" "${f%typ}png"; done

manual.typ

@@ -0,0 +1,238 @@
+#import "@preview/tidy:0.4.2"
+#import "@preview/codly:1.2.0": codly-init, codly
+#import "@preview/codly-languages:0.1.8": codly-languages
+#import "src/lib.typ" as chronos
+#import "src/participant.typ" as mod-par
+#import "docs/examples.typ"
+#import "docs/example.typ": example
+
+#let TYPST = image("gallery/typst.png", width: 1.5cm, height: 1.5cm, fit: "contain")
+
+#show: codly-init
+#codly(
+  languages: codly-languages
+)
+
+#set text(font: "Source Sans 3")
+
+#set heading(numbering: (..num) => if num.pos().len() < 4 {
+  numbering("1.1", ..num)
+})
+
+#align(center)[
+  #v(2cm)
+  #text(size: 2em)[*Chronos*]
+  
+  _v#chronos.version;_
+  #v(1cm)
+  #chronos.diagram({
+    import chronos: *
+    _par("u", display-name: [User], shape: "actor")
+    _par("wa", display-name: [Web App])
+    _par("tu", display-name: [Typst Universe], shape: "database")
+
+    _seq("u", "wa", comment: [Compile document], enable-dst: true)
+    _seq("wa", "tu", comment: [Fetch Chronos])
+    _seq("tu", "wa", dashed: true, slant: 10)
+    _seq("wa", "wa", comment: [Render])
+    _ret(comment: [Nice sequence diagram])
+  })
+]
+
+#pagebreak()
+
+#{
+  outline(indent: auto, depth: 3)
+}
+#show link: set text(fill: blue)
+
+#set page(numbering: "1/1", header: align(right)[chronos #sym.dash.em v#chronos.version])
+#set page(
+  header: align(left)[chronos #sym.dash.em v#chronos.version],
+  footer: context align(center, counter(page).display("1/1", both: true))
+)
+
+= Introduction
+
+This package lets you create nice sequence diagrams using the CeTZ package.
+
+= Usage
+
+#let import-stmt = "#import \"@preview/chronos:" + str(chronos.version) + "\""
+
+Simply import #link("https://typst.app/universe/package/chronos/")[chronos] and call the `diagram` function:
+#raw(block:true, lang: "typ", ```typ
+$import
+#chronos.diagram({
+  import chronos: *
+  ...
+})
+```.text.replace("$import", import-stmt))
+
+= Examples
+
+You can find the following examples and more in the #link("https://git.kb28.ch/HEL/circuiteria/src/branch/main/gallery")[gallery] directory
+
+== Some groups and sequences
+
+#example(```
+chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Bob", comment: "Authentication Request")
+  _seq("Bob", "Alice", comment: "Authentication Failure")
+
+  _grp("My own label", desc: "My own label2", {
+    _seq("Alice", "Log", comment: "Log attack start")
+    _grp("loop", desc: "1000 times", {
+      _seq("Alice", "Bob", comment: "DNS Attack")
+    })
+    _seq("Alice", "Bob", comment: "Log attack end")
+  })
+})
+```, wrap: false, vertical: true)
+
+#pagebreak(weak: true)
+
+== Lifelines
+
+#example(```
+chronos.diagram({
+  import chronos: *
+  _seq("alice", "bob", comment: "hello", enable-dst: true)
+  _seq("bob", "bob", comment: "self call", enable-dst: true)
+  _seq(
+    "bill", "bob",
+    comment: "hello from thread 2",
+    enable-dst: true,
+    lifeline-style: (fill: rgb("#005500"))
+  )
+  _seq("bob", "george", comment: "create", create-dst: true)
+  _seq(
+    "bob", "bill",
+    comment: "done in thread 2",
+    disable-src: true,
+    dashed: true
+  )
+  _seq("bob", "bob", comment: "rc", disable-src: true, dashed: true)
+  _seq("bob", "george", comment: "delete", destroy-dst: true)
+  _seq("bob", "alice", comment: "success", disable-src: true, dashed: true)
+})
+```, wrap: false, vertical: true)
+
+#pagebreak(weak: true)
+
+== Found and lost messages
+
+#example(```
+chronos.diagram({
+  import chronos: *
+  _seq("?", "Alice", comment: [?->\ *short* to actor1])
+  _seq("[", "Alice", comment: [\[->\ *from start* to actor1])
+  _seq("[", "Bob", comment: [\[->\ *from start* to actor2])
+  _seq("?", "Bob", comment: [?->\ *short* to actor2])
+  _seq("Alice", "]", comment: [->\]\ from actor1 *to end*])
+  _seq("Alice", "?", comment: [->?\ *short* from actor1])
+  _seq("Alice", "Bob", comment: [->\ from actor1 to actor2])
+})
+```, wrap: false, vertical: true)
+
+#pagebreak(weak: true)
+
+== Custom images
+
+#example(```
+let load-img(path) = image(
+  path,
+  width: 1.5cm, height: 1.5cm,
+  fit:"contain"
+)
+let TYPST = load-img("../gallery/typst.png")
+let FERRIS = load-img("../gallery/ferris.png")
+let ME = load-img("../gallery/me.jpg")
+
+chronos.diagram({
+  import chronos: *
+  _par("me", display-name: "Me", shape: "custom", custom-image: ME)
+  _par("typst", display-name: "Typst", shape: "custom", custom-image: TYPST)
+  _par("rust", display-name: "Rust", shape: "custom", custom-image: FERRIS)
+
+  _seq("me", "typst", comment: "opens document", enable-dst: true)
+  _seq("me", "typst", comment: "types document")
+  _seq("typst", "rust", comment: "compiles content", enable-dst: true)
+  _seq("rust", "typst", comment: "renders document", disable-src: true)
+  _seq("typst", "me", comment: "displays document", disable-src: true)
+})
+```, wrap: false, vertical: true)
+
+#pagebreak(weak: true)
+
+= Reference
+
+#let par-docs = tidy.parse-module(
+  read("docs/participants.typ"),
+  name: "Participants",
+  require-all-parameters: true,
+  old-syntax: true,
+  scope: (
+    chronos: chronos,
+    mod-par: mod-par,
+    TYPST: TYPST
+  )
+)
+#tidy.show-module(par-docs, show-outline: false, sort-functions: none)
+
+#pagebreak(weak: true)
+
+#let seq-docs = tidy.parse-module(
+  read("docs/sequences.typ"),
+  name: "Sequences",
+  require-all-parameters: true,
+  old-syntax: true,
+  scope: (
+    chronos: chronos,
+    examples: examples
+  )
+)
+#tidy.show-module(seq-docs, show-outline: false, sort-functions: none)
+
+#pagebreak(weak: true)
+
+#let grp-docs = tidy.parse-module(
+  read("docs/groups.typ"),
+  name: "Groups",
+  require-all-parameters: true,
+  old-syntax: true,
+  scope: (
+    chronos: chronos,
+    examples: examples
+  )
+)
+#tidy.show-module(grp-docs, show-outline: false, sort-functions: none)
+
+#pagebreak(weak: true)
+
+#let gap-sep-docs = tidy.parse-module(
+  read("docs/gaps_seps.typ"),
+  name: "Gaps and separators",
+  require-all-parameters: true,
+  old-syntax: true,
+  scope: (
+    chronos: chronos,
+    examples: examples
+  )
+)
+#tidy.show-module(gap-sep-docs, show-outline: false, sort-functions: none)
+
+#pagebreak(weak: true)
+
+#let notes-docs = tidy.parse-module(
+  read("docs/notes.typ"),
+  name: "Notes",
+  require-all-parameters: true,
+  old-syntax: true,
+  scope: (
+    chronos: chronos,
+    examples: examples
+  )
+)
+#tidy.show-module(notes-docs, show-outline: false)

src/consts.typ

@@ -2,6 +2,10 @@
 #let PAR-SPACE = 10
 #let COMMENT-PAD = 8
 #let LIFELINE-W = 10
+#let CREATE-OFFSET = 15
+#let DEFAULT-SLANT = 10
+#let CROSS-TIP-SIZE = 4
+#let CIRCLE-TIP-RADIUS = 3
 
 #let SYM-GAP = 5
 #let PAR-PAD = (5pt, 3pt)
@@ -15,6 +19,12 @@
 #let COLLECTIONS-DY = 3
 #let QUEUE-PAD = (5pt, 3pt)
 
+#let NOTE-PAD = (6, 3)
+#let NOTE-CORNER-SIZE = 6
+#let NOTE-GAP = 3
+#let NOTE-HEX-PAD = (6, 8)
+
 #let COL-DESTRUCTION = rgb("#A80238")
 #let COL-GRP-NAME = rgb("#EEEEEE")
 #let COL-SEP-NAME = rgb("#EEEEEE")
+#let COL-NOTE = rgb("#FEFFDD")

src/diagram.typ

@@ -1,6 +1,7 @@
-#import "utils.typ": get-group-span
+#import "utils.typ": get-group-span, fit-canvas
 #import "renderer.typ": render
 #import "participant.typ" as participant: _par, PAR-SPECIALS
+#import "sequence.typ": _seq
 
 #let _gap(size: 20) = {
   return ((
@@ -9,7 +10,28 @@
   ),)
 }
 
-#let diagram(elements) = {
+#let _evt(participant, event) = {
+  return ((
+    type: "evt",
+    participant: participant,
+    event: event,
+    lifeline-style: auto
+  ),)
+}
+
+#let _col(p1, p2, width: auto, margin: 0, min-width: 0, max-width: none) = {
+  return ((
+    type: "col",
+    p1: p1,
+    p2: p2,
+    width: width,
+    margin: margin,
+    min-width: min-width,
+    max-width: max-width
+  ),)
+}
+
+#let diagram(elements, width: auto) = {
   if elements == none {
     return
   }
@@ -18,11 +40,12 @@
   let elmts = elements
   let i = 0
 
-  // Flatten groups
+  let activation-history = ()
+
+  // Flatten groups + convert returns
   while i < elmts.len() {
     let elmt = elmts.at(i)
     if elmt.type == "grp" {
-      let grp-elmts = elmt.elmts
       elmt.elmts = elmt.elmts.map(e => {
         if e.type == "seq" {
           if e.p1 == "?" {
@@ -36,19 +59,50 @@
       elmts.at(i) = elmt
       elmts = (
         elmts.slice(0, i + 1) +
-        grp-elmts +
+        elmt.elmts +
         ((
-          type: "grp-end"
+          type: "grp-end",
+          start-i: i
         ),) +
         elmts.slice(i+1)
       )
+    } else if elmt.type == "grp-end" {
+      // Put back elements in group because they might have changed
+      elmts.at(elmt.start-i).elmts = elmts.slice(elmt.start-i + 1, i)
+
+    } else if elmt.type == "seq" {
+      if elmt.enable-dst {
+        activation-history.push(elmt)
+      }
+    } else if elmt.type == "evt" {
+      if elmt.event == "enable" {
+        for elmt2 in elmts.slice(0, i).rev() {
+          if elmt2.type == "seq" {
+            activation-history.push(elmt2)
+            break
+          }
+        }
+      }
+    } else if elmt.type == "ret" {
+      if activation-history.len() == 0 {
+        panic("Cannot return if no lifeline is activated")
+      }
+      let seq = activation-history.pop()
+      elmts.at(i) = _seq(
+        seq.p2, seq.p1,
+        comment: elmt.comment,
+        disable-src: true,
+        dashed: true
+      ).first()
     }
     i += 1
   }
 
   // List participants
   let linked = ()
-  for elmt in elmts {
+  let last-seq = none
+  let last-note = none
+  for (i, elmt) in elmts.enumerate() {
     if elmt.type == "par" {
       participants.push(elmt)
     } else if elmt.type == "seq" {
@@ -64,15 +118,78 @@
         participants.at(i).from-start = false
       }
 
+      let p1 = elmt.p1
+      let p2 = elmt.p2
       if elmt.p1 == "?" {
-        linked.push("?" + elmt.p2)
+        p1 = "?" + elmt.p2
-      } else {
-        linked.push(elmt.p1)
       }
       if elmt.p2 == "?" {
-        linked.push(elmt.p1 + "?")
+        p2 = elmt.p1 + "?"
-      } else {
+      }
-        linked.push(elmt.p2)
+      linked.push(p1)
+      linked.push(p2)
+      last-seq = (
+        elmt: elmt,
+        i: i,
+        p1: p1,
+        p2: p2
+      )
+    } else if elmt.type == "note" {
+      elmt.insert("linked", elmt.pos == none and elmt.side != "across")
+      if elmt.pos == none and elmt.side != "across" {
+        let names = participants.map(p => p.name)
+        let i1 = names.position(n => n == last-seq.p1)
+        let i2 = names.position(n => n == last-seq.p2)
+        let pars = ((i1, last-seq.p1), (i2, last-seq.p2)).sorted(key: p => p.first())
+        if elmt.side == "left" {
+          elmt.pos = pars.first().last()
+        } else if elmt.side == "right" {
+          elmt.pos = pars.last().last()
+        }
+
+        let seq = last-seq.elmt
+        seq.insert("linked-note", elmt)
+        elmts.at(last-seq.i) = seq
+      }
+      if elmt.aligned {
+        let n = last-note.elmt
+        n.aligned-with = elmt
+        elmts.at(last-note.i) = n
+      }
+      elmts.at(i) = elmt
+      if elmt.side == "left" {
+        linked.push("[")
+      } else if elmt.side == "right" {
+        linked.push("]")
+      }
+
+      let pars = none
+      if type(elmt.pos) == str {
+        pars = (elmt.pos,)
+      } else if type(elmt.pos) == array {
+        pars = elmt.pos
+      }
+      if pars != none {
+        for par in pars {
+          if not participant._exists(participants, par) {
+            participants.push(_par(par).first())
+          }
+        }
+      }
+
+      last-note = (
+        elmt: elmt,
+        i: i
+      )
+    } else if elmt.type == "evt" {
+      let par = elmt.participant
+      if not participant._exists(participants, par) {
+        let p = _par(par, from-start: elmt.event != "create").first()
+        participants.push(p)
+      
+      } else if elmt.event == "create" {
+        let i = participants.position(p => p.name == par)
+        participants.at(i).from-start = false
       }
     }
   }
@@ -115,7 +232,7 @@
 
   // Compute groups spans (horizontal)
   for (i, elmt) in elmts.enumerate() {
-    if elmt.type == "grp" {
+    if elmt.type == "grp" or elmt.type == "alt" {
       let (min-i, max-i) = get-group-span(participants, elmt)
       elmts.at(i).insert("min-i", min-i)
       elmts.at(i).insert("max-i", max-i)
@@ -128,7 +245,8 @@
     }
   }
 
-  render(participants, elmts)
+  let canvas = render(participants, elmts)
+  fit-canvas(canvas, width: width)
 }
 
 #let from-plantuml(code) = {

src/group.typ

@@ -1,4 +1,4 @@
-#import "@preview/cetz:0.2.2": draw
+#import "/src/cetz.typ": draw
 #import "consts.typ": *
 
 #let _grp(name, desc: none, type: "default", elmts) = {
@@ -11,6 +11,36 @@
   ),)
 }
 
+#let _alt(desc, elmts, ..args) = {
+  let all-elmts = ()
+  all-elmts += elmts
+  let args = args.pos()
+  for i in range(0, args.len(), step: 2) {
+    let else-desc = args.at(i)
+    let else-elmts = args.at(i + 1, default: ())
+    all-elmts.push((
+      type: "else",
+      desc: else-desc
+    ))
+    all-elmts += else-elmts
+  }
+
+  return _grp("alt", desc: desc, type: "alt", all-elmts)
+}
+
+#let _loop(desc, min: none, max: auto, elmts) = {
+  let name = "loop"
+  if min != none {
+    if max == auto {
+      max = "*"
+    }
+    name += "(" + str(min) + "," + str(max) + ")"
+  }
+  _grp(name, desc: desc, type: "loop", elmts)
+}
+#let _opt(desc, elmts) = grp("opt", desc: desc, type: "opt", elmts)
+#let _break(desc, elmts) = grp("break", desc: desc, type: "break", elmts)
+
 #let render(x0, x1, y0, y1, group) = {
   let shapes = ()
   let name = text(group.name, weight: "bold")
@@ -44,7 +74,7 @@
   if group.desc != none {
     shapes += draw.content(
       (x0 + w, y0),
-      text([\[#group.desc\]], weight: "bold"),
+      text([\[#group.desc\]], weight: "bold", size: .8em),
       anchor: "north-west",
       padding: 3pt
     )
@@ -52,3 +82,18 @@
 
   return shapes
 }
+
+#let render-else(x0, x1, y, elmt) = {
+  let shapes = draw.line(
+    (x0, y),
+    (x1, y),
+    stroke: (dash: (2pt, 1pt), thickness: .5pt)
+  )
+  shapes += draw.content(
+    (x0, y),
+    text([\[#elmt.desc\]], weight: "bold", size: .8em),
+    anchor: "north-west",
+    padding: 3pt
+  )
+  return shapes
+}

src/lib.typ

@@ -1,6 +1,9 @@
-#import "diagram.typ": diagram, from-plantuml, _gap
+#let version = version(0, 2, 1)
+#import "diagram.typ": diagram, from-plantuml, _gap, _evt, _col
 
-#import "sequence.typ": _seq
+#import "sequence.typ": _seq, _ret
-#import "group.typ": _grp
+#import "group.typ": _grp, _loop, _alt, _opt, _break
 #import "participant.typ": _par
-#import "separator.typ": _sep
+#import "separator.typ": _sep, _delay
+#import "note.typ": _note
+#import "sync.typ": _sync

src/note.typ

@@ -0,0 +1,185 @@
+#import "/src/cetz.typ": draw
+#import "consts.typ": *
+
+#let SIDES = (
+  "left",
+  "right",
+  "over",
+  "across"
+)
+
+#let SHAPES = (
+  "default",
+  "rect",
+  "hex"
+)
+
+#let _note(side, content, pos: none, color: COL-NOTE, shape: "default", aligned: false) = {
+  if side == "over" {
+    if pos == none {
+      panic("Pos cannot be none with side 'over'")
+    }
+  }
+  if aligned {
+    if side != "over" {
+      panic("Aligned notes can only be over a participant (got side '" + side + "')")
+    }
+  }
+  if color == auto {
+    color = COL-NOTE
+  }
+  return ((
+    type: "note",
+    side: side,
+    content: content,
+    pos: pos,
+    color: color,
+    shape: shape,
+    aligned: aligned,
+    aligned-with: none
+  ),)
+}
+
+#let get-note-box(note) = {
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let inset = (
+    left: PAD.last() * 1pt,
+    right: PAD.last() * 1pt,
+    top: PAD.first() * 1pt,
+    bottom: PAD.first() * 1pt,
+  )
+  if note.shape == "default" {
+    inset.right += NOTE-CORNER-SIZE * 1pt
+  }
+  if note.side == "left" {
+    inset.right += NOTE-GAP * 1pt
+  } else if note.side == "right" {
+    inset.left += NOTE-GAP * 1pt
+  }
+  return box(note.content, inset: inset)
+}
+
+#let get-size(note) = {
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let m = measure(box(note.content))
+  let w = m.width / 1pt + PAD.last() * 2
+  let h = m.height / 1pt + PAD.first() * 2
+  if note.shape == "default" {
+    w += NOTE-CORNER-SIZE
+  }
+  return (
+    width: w,
+    height: h
+  )
+}
+
+#let _get-base-x(pars-i, x-pos, note) = {
+  if note.side == "across" {
+    return (x-pos.first() + x-pos.last()) / 2
+  }
+  if note.side == "over" {
+    if type(note.pos) == array {
+      let xs = note.pos.map(par => x-pos.at(pars-i.at(par)))
+      return (calc.min(..xs) + calc.max(..xs)) / 2
+    }
+  }
+  return x-pos.at(pars-i.at(note.pos))
+}
+
+#let render(pars-i, x-pos, note, y, lifelines) = {
+  let shapes = ()
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let m = measure(box(note.content))
+  let w = m.width / 1pt + PAD.last() * 2
+  let h = m.height / 1pt + PAD.first() * 2
+  let total-w = w
+  if note.shape == "default" {
+    total-w += NOTE-CORNER-SIZE
+  }
+
+  let base-x = _get-base-x(pars-i, x-pos, note)
+
+  let i = none
+  if note.pos != none and type(note.pos) == str {
+    i = pars-i.at(note.pos)
+  }
+  let x0 = base-x
+  if note.side == "left" {
+    x0 -= NOTE-GAP
+    x0 -= total-w
+    if lifelines.at(i).level != 0 {
+      x0 -= LIFELINE-W / 2
+    }
+  } else if note.side == "right" {
+    x0 += NOTE-GAP
+    x0 += lifelines.at(i).level * LIFELINE-W / 2
+  } else if note.side == "over" or note.side == "across" {
+    x0 -= total-w / 2
+  }
+
+  let x1 = x0 + w
+  let x2 = x0 + total-w
+  let y0 = y
+
+  if note.linked {
+    y0 += h / 2
+  }
+  let y1 = y0 - h
+
+  if note.shape == "default" {
+    shapes += draw.merge-path(
+      stroke: black + .5pt,
+      fill: note.color,
+      close: true,
+      {
+        draw.line(
+          (x0, y0),
+          (x1, y0),
+          (x2, y0 - NOTE-CORNER-SIZE),
+          (x2, y1),
+          (x0, y1)
+        )
+      }
+    )
+    shapes += draw.line((x1, y0), (x1, y0 - NOTE-CORNER-SIZE), (x2, y0 - NOTE-CORNER-SIZE), stroke: black + .5pt)
+  } else if note.shape == "rect" {
+    shapes += draw.rect(
+      (x0, y0),
+      (x2, y1),
+      stroke: black + .5pt,
+      fill: note.color
+    )
+  } else if note.shape == "hex" {
+    let lx = x0 + PAD.last()
+    let rx = x2 - PAD.last()
+    let my = (y0 + y1) / 2
+    shapes += draw.merge-path(
+      stroke: black + .5pt,
+      fill: note.color,
+      close: true,
+      {
+        draw.line(
+          (lx, y0),
+          (rx, y0),
+          (x2, my),
+          (rx, y1),
+          (lx, y1),
+          (x0, my),
+        )
+      }
+    )
+  }
+
+  shapes += draw.content(
+    ((x0 + x1)/2, (y0 + y1)/2),
+    note.content,
+    anchor: "center"
+  )
+
+  if note.aligned-with == none and (note.pos != none or note.side == "across") {
+    y -= h
+  }
+
+  let r = (y, shapes)
+  return r
+}

src/participant.typ

@@ -1,4 +1,4 @@
-#import "@preview/cetz:0.2.2": draw
+#import "/src/cetz.typ": draw
 #import "consts.typ": *
 
 #let PAR-SPECIALS = "?[]"
@@ -13,6 +13,7 @@
   "queue",
   "custom"
 )
+#let DEFAULT-COLOR = rgb("#E2E2F0")
 
 #let _par(
   name,
@@ -20,9 +21,14 @@
   from-start: true,
   invisible: false,
   shape: "participant",
-  color: rgb("#E2E2F0"),
+  color: DEFAULT-COLOR,
-  custom-image: none
+  custom-image: none,
+  show-bottom: true,
+  show-top: true,
 ) = {
+  if color == auto {
+    color = DEFAULT-COLOR
+  }
   return ((
     type: "par",
     name: name,
@@ -31,7 +37,9 @@
     invisible: invisible,
     shape: shape,
     color: color,
-    custom-image: custom-image
+    custom-image: custom-image,
+    show-bottom: show-bottom,
+    show-top: show-top
   ),)
 }
 

src/renderer.typ

@@ -1,11 +1,13 @@
-#import "@preview/cetz:0.2.2": canvas, draw
+#import "/src/cetz.typ": canvas, draw
-#import "utils.typ": get-participants-i, get-style
+#import "utils.typ": get-participants-i, get-style, normalize-units
 #import "group.typ"
 #import "participant.typ"
 #import participant: PAR-SPECIALS
 #import "sequence.typ"
 #import "separator.typ"
+#import "sync.typ"
 #import "consts.typ": *
+#import "note.typ" as note: get-note-box
 
 #let DEBUG-INVISIBLE = false
 
@@ -18,6 +20,16 @@
   let pars-i = get-participants-i(participants)
   let cells = ()
 
+  // Unwrap syncs
+  let i = 0
+  while i < elements.len() {
+    let elmt = elements.at(i)
+    if elmt.type == "sync" {
+      elements = elements.slice(0, i + 1) + elmt.elmts + elements.slice(i + 1)
+    }
+    i += 1
+  }
+
   // Compute max lifeline levels
   for elmt in elements {
     if elmt.type == "seq" {
@@ -49,6 +61,54 @@
         p.max-lifelines = calc.max(p.max-lifelines, p.lifeline-lvl)
         participants.at(i2) = p
       }
+    } else if elmt.type == "evt" {
+      let par-name = elmt.participant
+      let i = pars-i.at(par-name)
+      let par = participants.at(i)
+      if elmt.event == "disable" or elmt.event == "destroy" {
+        par.lifeline-lvl -= 1
+      
+      } else if elmt.event == "enable" {
+        par.lifeline-lvl += 1
+        par.max-lifelines = calc.max(par.max-lifelines, par.lifeline-lvl)
+      }
+      participants.at(i) = par
+    
+    } else if elmt.type == "note" {
+      let (p1, p2) = (none, none)
+      let cell = none
+      if elmt.side == "left" {
+        p1 = "["
+        p2 = elmt.pos
+        cell = get-note-box(elmt)
+      } else if elmt.side == "right" {
+        p1 = elmt.pos
+        p2 = "]"
+        cell = get-note-box(elmt)
+      } else if elmt.side == "over" {
+        if elmt.aligned-with != none {
+          let box1 = get-note-box(elmt)
+          let box2 = get-note-box(elmt.aligned-with)
+          let m1 = measure(box1)
+          let m2 = measure(box2)
+          cell = box(width: (m1.width + m2.width) / 2, height: calc.max(m1.height, m2.height))
+          p1 = elmt.pos
+          p2 = elmt.aligned-with.pos
+        }
+      }
+
+      if p1 != none and p2 != none and cell != none {
+        let i1 = pars-i.at(p1)
+        let i2 = pars-i.at(p2)
+        cells.push(
+          (
+            elmt: elmt,
+            i1: calc.min(i1, i2),
+            i2: calc.max(i1, i2),
+            cell: cell
+          )
+        )
+      }
     }
   }
 
@@ -65,6 +125,28 @@
     widths.push(w1 / 2pt + w2 / 2pt + PAR-SPACE)
   }
 
+  // Compute minimum width for over notes
+  for n in elements.filter(e => (e.type == "note" and
+                                 e.side == "over" and 
+                                 type(e.pos) == str)) {
+    
+    let m = note.get-size(n)
+    let i = pars-i.at(n.pos)
+
+    if i < widths.len() {
+      widths.at(i) = calc.max(
+        widths.at(i),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+    if i > 0 {
+      widths.at(i - 1) = calc.max(
+        widths.at(i - 1),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+  }
+
   // Compute minimum width for simple sequences (spanning 1 column)
   for cell in cells.filter(c => c.i2 - c.i1 == 1) {
     let m = measure(cell.cell)
@@ -74,6 +156,21 @@
     )
   }
 
+  // Compute minimum width for self sequences
+  for cell in cells.filter(c => c.elmt.type == "seq" and c.i1 == c.i2) {
+    let m = measure(cell.cell)
+    let i = cell.i1
+    if cell.elmt.flip {
+      i -= 1
+    }
+    if 0 <= i and i < widths.len() {
+      widths.at(i) = calc.max(
+        widths.at(i),
+        m.width / 1pt + COMMENT-PAD
+      )
+    }
+  }
+
   // Compute remaining widths for longer sequences (spanning multiple columns)
   let multicol-cells = cells.filter(c => c.i2 - c.i1 > 1)
   multicol-cells = multicol-cells.sorted(key: c => {
@@ -97,6 +194,40 @@
     }
     widths.at(i) = w
   }
+
+  for elmt in elements {
+    if elmt.type == "col" {
+      let i1 = pars-i.at(elmt.p1)
+      let i2 = pars-i.at(elmt.p2)
+      if calc.abs(i1 - i2) != 1 {
+        let i-min = calc.min(i1, i2)
+        let i-max = calc.max(i1, i2)
+        let others = pars-i.pairs()
+                           .sorted(key: p => p.last())
+                           .slice(i-min + 1, i-max)
+                           .map(p => "'" + p.first() + "'")
+                           .join(", ")
+        panic(
+          "Column participants must be consecutive (participants (" +
+          others +
+          ") are in between)"
+        )
+      }
+      let i = calc.min(i1, i2)
+
+      if elmt.width != auto {
+        widths.at(i) = normalize-units(elmt.width)
+      }
+
+      let width = widths.at(i)
+      width = calc.max(width, normalize-units(elmt.min-width))
+      if elmt.max-width != none {
+        width = calc.min(width, normalize-units(elmt.max-width))
+      }
+      widths.at(i) = width + normalize-units(elmt.margin)
+    }
+  }
+
   return widths
 }
 
@@ -114,17 +245,20 @@
 
   let draw-seq = sequence.render.with(pars-i, x-pos, participants)
   let draw-group = group.render.with()
+  let draw-else = group.render-else.with()
   let draw-sep = separator.render.with(x-pos)
   let draw-par = participant.render.with(x-pos)
+  let draw-note = note.render.with(pars-i, x-pos)
+  let draw-sync = sync.render.with(pars-i, x-pos, participants)
   
   // Draw participants (start)
   for p in participants {
-    if p.from-start and not p.invisible {
+    if p.from-start and not p.invisible and p.show-top {
       shapes += draw-par(p)
     }
   }
 
-  let y = -Y-SPACE
+  let y = 0
   let groups = ()
   let lifelines = participants.map(_ => (
     level: 0,
@@ -141,6 +275,7 @@
 
     // Groups (start) -> reserve space for labels + store position
     } else if elmt.type == "grp" {
+      y -= Y-SPACE
       let m = measure(
         box(
           elmt.name,
@@ -152,17 +287,34 @@
         if g.at(1).max-i == elmt.max-i { g.at(3) += 1 }
         g
       })
+      if elmt.grp-type == "alt" {
+        elmt.insert("elses", ())
+      }
       groups.push((y, elmt, 0, 0))
-      y -= m.height / 1pt + Y-SPACE
+      y -= m.height / 1pt
     
     // Groups (end) -> actual drawing
     } else if elmt.type == "grp-end" {
+      y -= Y-SPACE
       let (start-y, group, start-lvl, end-lvl) = groups.pop()
       let x0 = x-pos.at(group.min-i) - start-lvl * 10 - 20
       let x1 = x-pos.at(group.max-i) + end-lvl * 10 + 20
       shapes += draw-group(x0, x1, start-y, y, group)
 
+      if group.grp-type == "alt" {
+        for (else-y, else-elmt) in group.elses {
+          shapes += draw-else(x0, x1, else-y, else-elmt)
+        }
+      }
+
+    // Alt's elses -> reserve space for label + store position
+    } else if elmt.type == "else" {
       y -= Y-SPACE
+      let m = measure(text([\[#elmt.desc\]], weight: "bold", size: .8em))
+      groups.last().at(1).elses.push((
+        y, elmt
+      ))
+      y -= m.height / 1pt
 
     // Separator
     } else if elmt.type == "sep" {
@@ -173,9 +325,72 @@
     // Gap
     } else if elmt.type == "gap" {
       y -= elmt.size
+
+    // Delay
+    } else if elmt.type == "delay" {
+      let y0 = y
+      let y1 = y - elmt.size
+      for (i, line) in lifelines.enumerate() {
+        line.lines.push(("delay-start", y0))
+        line.lines.push(("delay-end", y1))
+        lifelines.at(i) = line
+      }
+      if elmt.name != none {
+        let x0 = x-pos.first()
+        let x1 = x-pos.last()
+        shapes += draw.content(
+          ((x0 + x1) / 2, (y0 + y1) / 2),
+          anchor: "center",
+          elmt.name
+        )
+      }
+      y = y1
+    
+    // Event
+    } else if elmt.type == "evt" {
+      let par-name = elmt.participant
+      let i = pars-i.at(par-name)
+      let par = participants.at(i)
+      let line = lifelines.at(i)
+      if elmt.event == "disable" {
+        line.level -= 1
+        line.lines.push(("disable", y))
+      
+      } else if elmt.event == "destroy" {
+        line.lines.push(("destroy", y))
+      
+      } else if elmt.event == "enable" {
+        line.level += 1
+        line.lines.push(("enable", y, elmt.lifeline-style))
+      
+      } else if elmt.event == "create" {
+        y -= CREATE-OFFSET
+        shapes += participant.render(x-pos, par, y: y)
+        line.lines.push(("create", y))
+      }
+      lifelines.at(i) = line
+    
+    // Note
+    } else if elmt.type == "note" {
+      if not elmt.linked {
+        if not elmt.aligned {
+          y -= Y-SPACE
+        }
+        let shps
+        (y, shps) = draw-note(elmt, y, lifelines)
+        shapes += shps
+      }
+
+    // Synched sequences
+    } else if elmt.type == "sync" {
+      let shps
+      (y, lifelines, shps) = draw-sync(elmt, y, lifelines)
+      shapes += shps
     }
   }
 
+  y -= Y-SPACE
+
   // Draw vertical lines + lifelines + end participants
   shapes += draw.on-layer(-1, {
     if DEBUG-INVISIBLE {
@@ -217,7 +432,11 @@
             draw.line(
               (x, last-y),
               (x, line.at(1)),
-              stroke: (dash: "dashed", paint: gray.darken(40%))
+              stroke: (
+                dash: "dashed",
+                paint: gray.darken(40%),
+                thickness: .5pt
+              )
             )
           }
           lines.push(line)
@@ -239,13 +458,39 @@
           if event == "destroy" {
             destructions.push((x + lvl * LIFELINE-W / 2, line.at(1)))
           }
+        } else if event == "delay-start" {
+          draw.line(
+            (x, last-y),
+            (x, line.at(1)),
+            stroke: (
+              dash: "dashed",
+              paint: gray.darken(40%),
+              thickness: .5pt
+            )
+          )
+          last-y = line.at(1)
+        } else if event == "delay-end" {
+          draw.line(
+            (x, last-y),
+            (x, line.at(1)),
+            stroke: (
+              dash: "loosely-dotted",
+              paint: gray.darken(40%),
+              thickness: .8pt
+            )
+          )
+          last-y = line.at(1)
         }
       }
 
       draw.line(
         (x, last-y),
         (x, y),
-        stroke: (dash: "dashed", paint: gray.darken(40%))
+        stroke: (
+          dash: "dashed",
+          paint: gray.darken(40%),
+          thickness: .5pt
+        )
       )
 
       // Draw lifeline rectangles (reverse for bottom to top)
@@ -267,8 +512,10 @@
       }
 
       // Draw participants (end)
+      if p.show-bottom {
         draw-par(p, y: y, bottom: true)
       }
+    }
   })
 
   shapes

src/separator.typ

@@ -1,4 +1,4 @@
-#import "@preview/cetz:0.2.2": draw
+#import "/src/cetz.typ": draw
 #import "consts.typ": *
 
 #let _sep(name) = {
@@ -8,8 +8,17 @@
   ),)
 }
 
+#let _delay(name: none, size: 30) = {
+  return ((
+    type: "delay",
+    name: name,
+    size: size
+  ),)
+}
+
 #let render(x-pos, elmt, y) = {
   let shapes = ()
+  y -= Y-SPACE
 
   let x0 = x-pos.first() - 20
   let x1 = x-pos.last() + 20
@@ -48,7 +57,6 @@
     fill: COL-SEP-NAME
   )
   y -= h / 2
-  y -= Y-SPACE
 
   let r = (y, shapes)
   return r

src/sequence.typ

@@ -1,13 +1,60 @@
-#import "@preview/cetz:0.2.2": draw
+#import "/src/cetz.typ": draw, vector
 #import "consts.typ": *
 #import "participant.typ"
+#import "note.typ"
+
+#let get-arrow-marks(sym, color) = {
+  if sym == none {
+    return none
+  }
+  if type(sym) == array {
+    return sym.map(s => get-arrow-marks(s, color))
+  }
+  (
+    "": none,
+    ">": (symbol: ">", fill: color),
+    ">>": (symbol: "straight"),
+    "\\": (symbol: ">", fill: color, harpoon: true, flip: true),
+    "\\\\": (symbol: "straight", harpoon: true, flip: true),
+    "/": (symbol: ">", fill: color, harpoon: true),
+    "//": (symbol: "straight", harpoon: true),
+    "x": none,
+    "o": none,
+  ).at(sym)
+}
+
+#let reverse-arrow-mark(mark) = {
+  if type(mark) == array {
+    return mark.map(m => reverse-arrow-mark(m))
+  }
+  let mark2 = mark
+  if type(mark) == dictionary and mark.at("harpoon", default: false) {
+    let flipped = mark.at("flip", default: false)
+    mark2.insert("flip", not flipped)
+  }
+  return mark2
+}
+
+#let is-tip-of-type(type_, tip) = {
+  if type(tip) == str and tip == type_ {
+    return true
+  }
+  if type(tip) == array and tip.contains(type_) {
+    return true
+  }
+  return false
+}
+#let is-circle-tip = is-tip-of-type.with("o")
+#let is-cross-tip = is-tip-of-type.with("x")
 
 #let _seq(
   p1,
   p2,
   comment: none,
+  comment-align: "left",
   dashed: false,
-  tip: "default",
+  start-tip: "",
+  end-tip: ">",
   color: black,
   flip: false,
   enable-dst: false,
@@ -16,15 +63,18 @@
   destroy-dst: false,
   disable-src: false,
   destroy-src: false,
-  lifeline-style: auto
+  lifeline-style: auto,
+  slant: none
 ) = {
   return ((
     type: "seq",
     p1: p1,
     p2: p2,
     comment: comment,
+    comment-align: comment-align,
     dashed: dashed,
-    tip: tip,
+    start-tip: start-tip,
+    end-tip: end-tip,
     color: color,
     flip: flip,
     enable-dst: enable-dst,
@@ -34,19 +84,42 @@
     disable-src: disable-src,
     destroy-src: destroy-src,
     lifeline-style: lifeline-style,
+    slant: slant
+  ),)
+}
+
+#let _ret(comment: none) = {
+  return ((
+    type: "ret",
+    comment: comment
   ),)
 }
 
 #let render(pars-i, x-pos, participants, elmt, y, lifelines) = {
   let shapes = ()
 
-  // Reserve space for comment
+  y -= Y-SPACE
-  if elmt.comment != none {
-    y -= measure(box(elmt.comment)).height / 1pt + 6
-  }
 
   let i1 = pars-i.at(elmt.p1)
   let i2 = pars-i.at(elmt.p2)
+  let width = calc.abs(x-pos.at(i1) - x-pos.at(i2))
+
+  let h = 0
+  let comment = if elmt.comment == none {none} else {
+    let w = calc.min(width * 1pt, measure(elmt.comment).width)
+    box(
+      width: if i1 == i2 {auto} else {w},
+      elmt.comment
+    )
+  }
+  // Reserve space for comment
+  if comment != none {
+    h = calc.max(h, measure(comment).height / 1pt + 6)
+  }
+  if "linked-note" in elmt {
+    h = calc.max(h, note.get-size(elmt.linked-note).height / 2)
+  }
+  y -= h
 
   let start-info = (
     i: i1,
@@ -60,27 +133,38 @@
     y: y,
     ll-lvl: lifelines.at(i2).level * LIFELINE-W / 2
   )
+  let slant = if elmt.slant == auto {
+    DEFAULT-SLANT
+  } else if elmt.slant != none {
+    elmt.slant
+  } else {
+    0
+  }
+  end-info.y -= slant
+  if elmt.p1 == elmt.p2 {
+    end-info.y -= 10
+  }
 
   if elmt.disable-src {
     let src-line = lifelines.at(i1)
     src-line.level -= 1
-    src-line.lines.push(("disable", y))
+    src-line.lines.push(("disable", start-info.y))
     lifelines.at(i1) = src-line
   }
   if elmt.destroy-src {
     let src-line = lifelines.at(i1)
-    src-line.lines.push(("destroy", y))
+    src-line.lines.push(("destroy", start-info.y))
     lifelines.at(i1) = src-line
   }
   if elmt.disable-dst {
     let dst-line = lifelines.at(i2)
     dst-line.level -= 1
-    dst-line.lines.push(("disable", y))
+    dst-line.lines.push(("disable", end-info.y))
     lifelines.at(i2) = dst-line
   }
   if elmt.destroy-dst {
     let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("destroy", y))
+    dst-line.lines.push(("destroy", end-info.y))
     lifelines.at(i2) = dst-line
   }
   if elmt.enable-dst {
@@ -93,7 +177,7 @@
     let m = measure(box(par.display-name))
     let f = if i1 > i2 {-1} else {1}
     end-info.x -= (m.width + PAR-PAD.last() * 2) / 2pt * f
-    shapes += participant.render(x-pos, par, y: y)
+    shapes += participant.render(x-pos, par, y: end-info.y)
   }
 
   end-info.ll-lvl = lifelines.at(i2).level * LIFELINE-W / 2
@@ -117,13 +201,37 @@
   }
 
   let style = (
-    mark: (end: ">", fill: elmt.color),
+    mark: (
+      start: get-arrow-marks(elmt.start-tip, elmt.color),
+      end: get-arrow-marks(elmt.end-tip, elmt.color),
+      scale: 1.2
+    ),
     stroke: (
-      dash: if elmt.dashed {"dashed"} else {"solid"},
+      dash: if elmt.dashed {(2pt,2pt)} else {"solid"},
-      paint: elmt.color
+      paint: elmt.color,
+      thickness: .5pt
     )
   )
 
+  let y0 = start-info.y
+  if "linked-note" in elmt {
+    let shps = note.render(pars-i, x-pos, elmt.linked-note, start-info.y, lifelines).last()
+    shapes += shps
+  }
+
+  let flip-mark = end-info.i <= start-info.i
+  if elmt.flip {
+    flip-mark = not flip-mark
+  }
+  if flip-mark {
+    style.mark.end = reverse-arrow-mark(style.mark.end)
+  }
+
+  let pts
+  let comment-pt
+  let comment-anchor
+  let comment-angle = 0deg
+
   if elmt.p1 == elmt.p2 {
     if elmt.flip {
       x1 = start-info.lx
@@ -137,56 +245,143 @@
       calc.max(x1, x2) + 20
     }
 
-    if elmt.comment != none {
+    pts = (
-      shapes += draw.content(
+      (x1, start-info.y),
-        (x1, y),
+      (x-mid, start-info.y),
-        elmt.comment,
+      (x-mid, end-info.y),
-        anchor: if elmt.flip {"south-east"} else {"south-west"},
+      (x2, end-info.y)
-        padding: 3pt
     )
-    }
 
-    shapes += draw.line(
+    if comment != none {
-      (x1, y),
+      comment-anchor = (
-      (x-mid, y),
+        start: if x-mid < x1 {"south-east"} else {"south-west"},
-      (x-mid, y - 10),
+        end: if x-mid < x1 {"south-west"} else {"south-east"},
-      (x2, y - 10),
+        left: "south-west",
-      ..style
+        right: "south-east",
-    )
+        center: "south",
-    y -= 10
+      ).at(elmt.comment-align)
+
+      comment-pt = (
+        start: pts.first(),
+        end: pts.at(1),
+        left: if x-mid < x1 {pts.at(1)} else {pts.first()},
+        right: if x-mid < x1 {pts.first()} else {pts.at(1)},
+        center: (pts.first(), 50%, pts.at(1))
+      ).at(elmt.comment-align)
+    }
 
   } else {
-    if elmt.comment != none {
+    pts = (
-      let x = calc.min(x1, x2)
+      (x1, start-info.y),
-      if x2 < x1 {
+      (x2, end-info.y)
-        x += COMMENT-PAD
+    )
+
+    if comment != none {
+      let start-pt = pts.first()
+      let end-pt = pts.last()
+      if elmt.start-tip != "" {
+        start-pt = (pts.first(), COMMENT-PAD, pts.last())
       }
+      if elmt.end-tip != "" {
+        end-pt = (pts.last(), COMMENT-PAD, pts.first())
+      }
+
+      comment-pt = (
+        start: start-pt,
+        end: end-pt,
+        left: if x2 < x1 {end-pt} else {start-pt},
+        right: if x2 < x1 {start-pt} else {end-pt},
+        center: (start-pt, 50%, end-pt)
+      ).at(elmt.comment-align)
+
+      comment-anchor = (
+        start: if x2 < x1 {"south-east"} else {"south-west"},
+        end: if x2 < x1 {"south-west"} else {"south-east"},
+        left: "south-west",
+        right: "south-east",
+        center: "south",
+      ).at(elmt.comment-align)
+    }
+
+    let (p1, p2) = pts
+    if x2 < x1 {
+      (p1, p2) = (p2, p1)
+    }
+    comment-angle = vector.angle2(p1, p2)
+  }
+
+  // Start circle tip
+  if is-circle-tip(elmt.start-tip) {
+    shapes += draw.circle(pts.first(), radius: CIRCLE-TIP-RADIUS, stroke: none, fill: elmt.color, name: "_circle-start-tip")
+    pts.at(0) = "_circle-start-tip"
+  
+  // Start cross tip
+  } else if is-cross-tip(elmt.start-tip) {
+    let size = CROSS-TIP-SIZE
+    let cross-pt = (pts.first(), size * 2, pts.at(1))
+    shapes += draw.line(
+      (rel: (-size, -size), to: cross-pt),
+      (rel: (size, size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    shapes += draw.line(
+      (rel: (-size, size), to: cross-pt),
+      (rel: (size, -size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    pts.at(0) = cross-pt
+  }
+
+  // End circle tip
+  if is-circle-tip(elmt.end-tip) {
+    shapes += draw.circle(pts.last(), radius: 3, stroke: none, fill: elmt.color, name: "_circle-end-tip")
+    pts.at(pts.len() - 1) = "_circle-end-tip"
+  
+  // End cross tip
+  } else if is-cross-tip(elmt.end-tip) {
+    let size = CROSS-TIP-SIZE
+    let cross-pt = (pts.last(), size * 2, pts.at(pts.len() - 2))
+    shapes += draw.line(
+      (rel: (-size, -size), to: cross-pt),
+      (rel: (size, size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    shapes += draw.line(
+      (rel: (-size, size), to: cross-pt),
+      (rel: (size, -size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    pts.at(pts.len() - 1) = cross-pt
+  }
+
+  shapes += draw.line(..pts, ..style)
+
+  if comment != none {
     shapes += draw.content(
-        (x, y),
+      comment-pt,
-        elmt.comment,
+      comment,
-        anchor: "south-west",
+      anchor: comment-anchor,
+      angle: comment-angle,
       padding: 3pt
     )
   }
 
-    shapes += draw.line(
+  if elmt.create-dst {
-      (x1, y),
+    let dst-line = lifelines.at(i2)
-      (x2, y),
+    dst-line.lines.push(("create", end-info.y))
-      ..style
+    lifelines.at(i2) = dst-line
-    )
   }
   if elmt.enable-dst {
     let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("enable", y, elmt.lifeline-style))
+    dst-line.lines.push(("enable", end-info.y, elmt.lifeline-style))
     lifelines.at(i2) = dst-line
   }
-  if elmt.create-dst {
-    let dst-line = lifelines.at(i2)
-    dst-line.lines.push(("create", y))
-    lifelines.at(i2) = dst-line
-  }
-  y -= Y-SPACE
 
-  let r = (y, lifelines, shapes)
+  if "linked-note" in elmt {
+    let m = note.get-size(elmt.linked-note)
+    end-info.y = calc.min(end-info.y, y0 - m.height / 2)
+  }
+
+  let r = (end-info.y, lifelines, shapes)
   return r
 }

src/sync.typ

@@ -0,0 +1,27 @@
+#import "sequence.typ"
+
+#let _sync(elmts) = {
+  return ((
+    type: "sync",
+    elmts: elmts
+  ),)
+}
+
+#let render(pars-i, x-pos, participants, elmt, y, lifelines) = {
+  let draw-seq = sequence.render.with(pars-i, x-pos, participants)
+
+  let shapes = ()
+
+  let end-y = y
+
+  for e in elmt.elmts {
+    let yi
+    let shps
+    (yi, lifelines, shps) = draw-seq(e, y, lifelines)
+    shapes += shps
+    end-y = calc.min(end-y, yi)
+  }
+
+  let r = (end-y, lifelines, shapes)
+  return r
+}

src/utils.typ

@@ -1,3 +1,12 @@
+#let normalize-units(value) = {
+  if type(value) == int or type(value) == float {
+    return value
+  }
+  if type(value) == length {
+    return value / 1pt
+  }
+  panic("Unsupported type '" + str(type(value)) + "'")
+}
 #let get-participants-i(participants) = {
   let pars-i = (:)
   for (i, p) in participants.enumerate() {
@@ -21,8 +30,15 @@
       let (i0, i1) = get-group-span(participants, elmt)
       min-i = calc.min(min-i, i0)
       max-i = calc.max(max-i, i1)
+    } else if elmt.type == "sync" {
+      let (i0, i1) = get-group-span(participants, elmt)
+      min-i = calc.min(min-i, i0)
+      max-i = calc.max(max-i, i1)
     }
   }
+  if max-i < min-i {
+    (min-i, max-i) = (max-i, min-i)
+  }
   return (min-i, max-i)
 }
 
@@ -41,3 +57,26 @@
 
   panic("Invalid type for parameter mods, expected auto or dictionary, got " + str(type(mods)))
 }
+
+#let fit-canvas(canvas, width: auto) = layout(size => {
+  let m = measure(canvas)
+  let w = m.width
+  let h = m.height
+  let r = if w == 0pt {0} else {
+    if width == auto {1}
+    else if type(width) == length {
+      width / w
+    } else {
+      size.width * width / w
+    }
+  }
+  let new-w = w * r
+  let new-h = h * r
+  r *= 100%
+  
+  box(
+    width: new-w,
+    height: new-h,
+    scale(x: r, y: r, reflow: true, canvas)
+  )
+})

typst.toml

@@ -1,7 +1,7 @@
 [package]
 name = "chronos"
-version = "0.0.1"
+version = "0.2.1"
-compiler = "0.11.0"
+compiler = "0.13.1"
 repository = "https://git.kb28.ch/HEL/chronos"
 entrypoint = "src/lib.typ"
 authors = [
@@ -11,4 +11,4 @@ categories = ["visualization"]
 license = "Apache-2.0"
 description = "A package to draw sequence diagrams with CeTZ"
 keywords = ["sequence", "diagram", "plantuml"]
-exclude = [ "/gallery/*" ]
+exclude = [ "gallery", "justfile", "docs" ]