Doc comments for the functions this PR touches

crates/engine/src/cmd/prop.rs

@@ -1457,6 +1457,7 @@ fn convert_one_expr(s: &mut Session, cid: ItemId, lid: LayerId, uid: Uid) -> Res
     })
 }
 
+/// Returns the command specs for the property commands (get, set, keyframes, expressions and the rest).
 pub fn specs() -> Vec<CommandSpec> {
     vec![
         query!("prop.get", "Get Property", "{layer?, path|prop, time? (comp s)}", get),

crates/ui-egui/src/num_math.rs

@@ -126,6 +126,8 @@ struct Parser<'a> {
 }
 
 impl Parser<'_> {
+    /// Reads a sum or difference of terms, left to right.
+    /// Returns `None` on a syntax error or a non-finite result.
     fn expr(&mut self) -> Option<f64> {
         let mut v = self.term()?;
         while let Some(&op) = self.chars.peek() {
@@ -144,6 +146,8 @@ impl Parser<'_> {
         Some(v)
     }
 
+    /// Reads a product or quotient of factors, left to right.
+    /// Returns `None` on a syntax error, a division by zero or a non-finite result.
     fn term(&mut self) -> Option<f64> {
         let mut v = self.factor()?;
         while let Some(&op) = self.chars.peek() {
@@ -162,6 +166,8 @@ impl Parser<'_> {
         Some(v)
     }
 
+    /// Reads a signed factor, a bracketed expression or a number.
+    /// Nesting deeper than `MAX_DEPTH` gives `None`.
     fn factor(&mut self) -> Option<f64> {
         let c = *self.chars.peek()?;
         match c {
@@ -239,6 +245,7 @@ impl Parser<'_> {
 mod tests {
     use super::calc as eval;
 
+    /// Evaluates `text` with no current value, so a leading operator has nothing to apply to.
     fn abs(text: &str) -> Option<f64> {
         eval(text, None)
     }

crates/ui-egui/src/panels/effect_controls/rows.rs

@@ -260,6 +260,7 @@ fn value_mask(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &
     }
 }
 
+/// Draws an angle property's value cell as revolutions plus degrees and queues a set action when it is edited.
 fn value_angle(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
     let Value::Scalar(v) = value else {
         return;
@@ -275,6 +276,7 @@ fn value_angle(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value:
     cx.twirl_open(app, ui);
 }
 
+/// Draws a single-number property's value cell with its range, unit suffix and scrub speed, and queues a set action when it is edited.
 fn value_scalar(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) {
     let Value::Scalar(v) = value else {
         return;
@@ -308,6 +310,8 @@ fn value_scalar(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value:
     }
 }
 
+/// Draws one numeric cell per component of a point or vector property, with the pick crosshair for points.
+/// Returns the cell rectangles.
 fn value_vector(app: &mut EffectcraftApp, ui: &mut egui::Ui, cx: &PropCx, value: &Value, actions: &mut Actions) -> Vec<Rect> {
     let mut dims = vec![];
     let PropCx { t, uid, cy, vx, layer, prop, .. } = *cx;