diff options
| -rw-r--r-- | library/src/meta/counter.rs | 22 | ||||
| -rw-r--r-- | tests/ref/meta/counter.png | bin | 13675 -> 44350 bytes |
2 files changed, 20 insertions, 2 deletions
diff --git a/library/src/meta/counter.rs b/library/src/meta/counter.rs index 722c2e94..08ef4662 100644 --- a/library/src/meta/counter.rs +++ b/library/src/meta/counter.rs @@ -15,6 +15,22 @@ use crate::prelude::*; /// With the counter function, you can access and modify counters for pages, /// headings, figures, and more. Moreover, you can define custom counters for /// other things you want to count. +/// +/// ## Counter initial value +/// All counters start at zero by default, with the exception of the page counter +/// as pages always start at one. This means that if, in your application, your counter +/// should start at one. You can do this in one of two ways: +/// 1. You can set the counter to one before you start counting: `#counter("my_counter").update(1)`. +/// 2. You can increment the counter by one before your start counting: `#counter("my_counter").step(1)`. +/// +/// This is done so that, when using a counter to count the number of a certain type of elements, it will +/// return zero if there are no elements of this type. For example, if you want to count the number of +/// figures in a document, you can do this: +/// ```example +/// The number of figures in this document is #locate(loc => { +/// counter(figure).at(loc) +/// }) +/// ``` /// /// ## Displaying a counter /// To display the current value of the heading counter, you call the `counter` @@ -311,6 +327,7 @@ impl Counter { let delta = vt.introspector.page(location).get().saturating_sub(page.get()); state.step(NonZeroUsize::ONE, delta); } + Ok(state) } @@ -374,8 +391,9 @@ impl Counter { ) -> SourceResult<EcoVec<(CounterState, NonZeroUsize)>> { let mut vt = Vt { world, tracer, provider, introspector }; let mut state = CounterState(match &self.0 { - CounterKey::Selector(_) => smallvec![0], - _ => smallvec![1], + // special case, because pages always start at one. + CounterKey::Page => smallvec![1], + _ => smallvec![0], }); let mut page = NonZeroUsize::ONE; let mut stops = eco_vec![(state.clone(), page)]; diff --git a/tests/ref/meta/counter.png b/tests/ref/meta/counter.png Binary files differindex 7e9ea69d..6c29ac17 100644 --- a/tests/ref/meta/counter.png +++ b/tests/ref/meta/counter.png |
