DOC: Tag the bar, stairs and cells gallery figures by chart kind

crates/ironlab-gallery/src/figures/bar_chart.rs

@@ -42,7 +42,8 @@ pub fn figure() -> Figure {
         .tag("legend")
         .tag("comparison")
         .tag("categorical")
-        .tag("physics")
+        .tag("grouped")
+        .tag("aerodynamics")
         .parameter("dimensionality", "2D")
         .parameter("artists", SECTIONS.len() as i64)
         .parameter("data_points", 16)

crates/ironlab-gallery/src/figures/bar_variants.rs

@@ -67,7 +67,12 @@ pub fn figure() -> Figure {
         .tag("legend")
         .tag("categorical")
         .tag("ticks")
-        .tag("physics")
+        .tag("stacked")
+        .tag("horizontal")
+        .tag("floating")
+        .tag("highlighted")
+        .tag("tick-angle")
+        .tag("engineering")
         .parameter("dimensionality", "2D")
         .parameter("artists", 9)
         .parameter("data_points", 96)

crates/ironlab-gallery/src/figures/branch_coverage.rs

@@ -89,6 +89,11 @@ pub fn figure() -> Figure {
         .tag("categorical")
         .tag("aspect")
         .tag("simulations")
+        .tag("occupancy")
+        .tag("grouped-rows")
+        .tag("hidden-axis")
+        .tag("coverage")
+        .tag("testing")
         .parameter("dimensionality", "2D")
         .parameter("artists", 1)
         .parameter("data_points", 760)

crates/ironlab-gallery/src/figures/coverage_matrix.rs

@@ -84,6 +84,11 @@ pub fn figure() -> Figure {
         .tag("ticks")
         .tag("aspect")
         .tag("simulations")
+        .tag("occupancy")
+        .tag("heatmap")
+        .tag("tick-angle")
+        .tag("coverage")
+        .tag("testing")
         .parameter("dimensionality", "2D")
         .parameter("artists", 2)
         .parameter("data_points", 100)

crates/ironlab-gallery/src/figures/histogram.rs

@@ -80,6 +80,10 @@ pub fn figure() -> Figure {
         .tag("statistics")
         .tag("measurements")
         .tag("comparison")
+        .tag("histogram")
+        .tag("density")
+        .tag("stacked")
+        .tag("distribution")
         .parameter("dimensionality", "2D")
         .parameter("artists", 6)
         .parameter("data_points", 1071)

crates/ironlab-gallery/src/figures/histogram_2d.rs

@@ -76,7 +76,10 @@ pub fn figure() -> Figure {
         .tag("colorbar")
         .tag("aspect")
         .tag("statistics")
-        .tag("physics")
+        .tag("histogram")
+        .tag("2d-histogram")
+        .tag("density")
+        .tag("turbulence")
         .parameter("dimensionality", "2D")
         .parameter("artists", 2)
         .parameter("data_points", 2306)

crates/ironlab-gallery/src/figures/stairs.rs

@@ -64,6 +64,9 @@ pub fn figure() -> Figure {
         .tag("log")
         .tag("signals")
         .tag("measurements")
+        .tag("step")
+        .tag("sample-and-hold")
+        .tag("spectrum")
         .parameter("dimensionality", "2D")
         .parameter("artists", 4)
         .parameter("data_points", 692)

crates/ironlab-gallery/tests/browsing.rs

@@ -386,6 +386,14 @@ fn the_labels_of_the_gallery_are_the_words_a_reader_would_look_for() {
         "markers",
         "placement",
         "transparency",
+        "grouped",
+        "stacked",
+        "histogram",
+        "2d-histogram",
+        "density",
+        "tick-angle",
+        "occupancy",
+        "hidden-axis",
     ] {
         assert!(
             values.iter().any(|value| value == wanted),
@@ -395,6 +403,58 @@ fn the_labels_of_the_gallery_are_the_words_a_reader_would_look_for() {
     }
 }
 
+// Why: a reader looking for a kind of chart types the word they know for it, and the tag menu offers whole tags,
+// so each kind must be named by a tag rather than left to a title. These words name kinds of chart that the bar,
+// stairs and cells artists make, which no structural tag distinguishes: a stacked or grouped bar chart and a
+// histogram are all bars, and an occupancy matrix and a two-dimensional histogram are both cells. "2d" alone
+// would not do, because every flat figure's dimensionality parameter already reads "2D".
+#[test]
+fn each_kind_of_bar_and_cell_chart_is_found_by_its_name() {
+    let expect = |query: &str, titles: &[&str]| {
+        let mut got = found(query);
+        got.sort();
+        let mut want: Vec<String> = titles.iter().map(|title| (*title).to_owned()).collect();
+        want.sort();
+        assert_eq!(got, want, "{query:?} should find exactly these figures");
+    };
+    expect(
+        "tag:stacked",
+        &[
+            "Histograms",
+            "Stacked, horizontal, floating and highlighted bars",
+        ],
+    );
+    expect(
+        "tag:grouped",
+        &["Grouped bar chart", "Branch coverage occupancy matrix"],
+    );
+    expect(
+        "tag:histogram",
+        &[
+            "Histograms",
+            "Two-dimensional histogram and density contour",
+        ],
+    );
+    expect(
+        "tag:2d-histogram",
+        &["Two-dimensional histogram and density contour"],
+    );
+    expect(
+        "tag:angle",
+        &[
+            "Stacked, horizontal, floating and highlighted bars",
+            "Case by subroutine coverage matrix",
+        ],
+    );
+    expect(
+        "tag:occupancy",
+        &[
+            "Branch coverage occupancy matrix",
+            "Case by subroutine coverage matrix",
+        ],
+    );
+}
+
 // Why: the counts are what make the menu worth opening rather than guessing, and they have to come from the whole
 // gallery rather than from whatever the panel has drawn. The surfaces are the count worth pinning, because they
 // are the request the browser was built for and because several entries draw one without saying so in their title.