feat(glossy): adds hide/hidden modifier to suppress term display

There are cases where you might want a term referenced (ie from the
Glossary/Index), but don't want to display it. New modifiers
`hide`||`hidden` do exactly that.

glossy/src/gloss.typ

@@ -194,6 +194,8 @@
 //     - "long": Show only the long form.
 //     - "def" or "desc": Show the term's description instead of its name.
 //     - "a" or "an": Prepend an article, chosen from the entry (short or long form).
+//     - "hide" or "hidden": Use term (for the sake of the glossary/index),
+//     but don't display it.
 //   show-term (function): A function that renders the chosen term.
 //   term-links (boolean): If terms should be clickable links leading to glossary
 //
@@ -218,6 +220,9 @@
   if ("a" in modifiers or "an" in modifiers) and ("pl" in modifiers) {
     panic("Cannot use 'a'/'an' and 'pl' together.")
   }
+  if ("hidden" in modifiers or "hide" in modifiers) and modifiers.len() > 1{
+    panic("Cannot use 'hide'/'hidden' with other modifiers.")
+  }
 
   // ---------------------------------------------------------------------------
   // Retrieve the glossary entry and its label
@@ -297,8 +302,11 @@
   // If no explicit mode is given, the default behavior is:
   //   - On first use and if a long form exists, "both".
   //   - Otherwise, "short".
-  let determine_mode = (wants_both, wants_long, wants_short, is_first_use, long_available) => {
-    if wants_both {
+  let determine_mode = (wants_both, wants_long, wants_short, is_first_use, long_available, wants_hidden) => {
+    if wants_hidden {
+      // If it's hidden, nothing else matters
+      "hidden"
+    } else if wants_both {
       // Explicit request for "both":
       // If a long form exists, use "both", otherwise fall back to "short".
       if long_available {
@@ -336,10 +344,11 @@
   let wants_both = "both" in modifiers
   let wants_long = "long" in modifiers
   let wants_short = "short" in modifiers
+  let wants_hidden = ("hidden" in modifiers or "hide" in modifiers)
   let long_available = entry.long != none
 
   // Determine mode using the helper function
-  let mode = determine_mode(wants_both, wants_long, wants_short, is_first_use, long_available)
+  let mode = determine_mode(wants_both, wants_long, wants_short, is_first_use, long_available, wants_hidden)
 
   // Pluralize (if requested)
   let short-form = pluralize_term(entry.short, entry.plural)
@@ -362,25 +371,38 @@
   // Construct and return the final output
   // ---------------------------------------------------------------------------
   context {
-    let linked-term = if term-links and __has_glossary_entry(key) {
-      link(label(key), term)
-    } else {
-      term
-    }
-  let term-label = if wants_reference {
+    // Figure out our label (unless not wanted)
+    let term-label = if wants_reference {
       __term_label(key)
     } else {
       []
     }
-    [#article#show-term(linked-term)#metadata(term)#term-label]
-  // |^^^^^^^|^^^^^^^^^             |^^^^^^^^      |^^^^^^^^^^^^
-  // \_art.  |                      |              |
-  //         \_ apply user formatting function to the term
-  //                                |              |
-  //                                \_ metadata lets us label (ie makes it "labelable")
-  //                                               |
-  //                                               \_ i.e. <__gloss:key>, etc.
-  //                                                  for backlink from glossary
+
+    // Create the output content
+    if mode == "hidden" {
+      // just put the metadata+label out there
+      [#metadata("hidden term")#term-label]
+    } else {
+      // normal term display (ie not hidden)
+
+      // create the forward link, if watned
+      let linked-term = if term-links and __has_glossary_entry(key) {
+        link(label(key), term)
+      } else {
+        term
+      }
+
+      // and the final content
+      [#article#show-term(linked-term)#metadata(term)#term-label]
+      // |^^^^^|^^^^^^^^^             |^^^^^^^^      |^^^^^^^^^^^^
+      // \_art.|                      |              |
+      //       \_ apply user formatting function to the term
+      //                              |              |
+      //                              \_ metadata lets us label (ie makes it "labelable")
+      //                                             |
+      //                                             \_ i.e. <__gloss:key>, etc.
+      //                                                for backlink from glossary
+    }
   }
 }
 

glossy/tests/hidden-terms/test.typ

@@ -0,0 +1,33 @@
+#import "/lib.typ": *
+
+#let myGlossary = (
+  html: (
+    short: "HTML",
+    long: "Hypertext Markup Language",
+    description: "A standard language for creating web pages",
+    group: "Web"),
+  css: (
+    short: "CSS",
+    long: "Cascading Style Sheets",
+    description: "A language used for describing the presentation of a document",
+    group: "Web"),
+  tps: (
+    short: "TPS",
+    long: "test procedure specification",
+    description: "A document on how to run all the test procedures"),
+   unused: "Unused term, which shouldn't print in the glossary."
+)
+
+#show: init-glossary.with(myGlossary)
+
+#set page(height: auto, width: 6.5in, margin: 1em, numbering: "1")
+
+= Hiding terms
+
+Here's a hidden term: @html:hide
+
+Here's another hidden term: @css:hidden
+
+And here's a shown term: @tps
+
+#glossary()