From 5dccc1ac9ebe2a14a4de3481e83a166ec42b56e5 Mon Sep 17 00:00:00 2001
From: Oleksandr Kozachuk <oleksandr@kozachuk.info>
Date: Mon, 13 Apr 2026 18:33:13 +0200
Subject: [PATCH] Add WORDS for Programming-Tools word set

Walk dictionary linked list, print all visible word names.
Uses pending_define mechanism for dictionary access.
---
 crates/core/src/dictionary.rs | 22 ++++++++++++++++++
 crates/core/src/outer.rs      | 44 +++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/crates/core/src/dictionary.rs b/crates/core/src/dictionary.rs
index 3fdb2f6..eeaaf50 100644
--- a/crates/core/src/dictionary.rs
+++ b/crates/core/src/dictionary.rs
@@ -409,6 +409,28 @@ impl Dictionary {
         Ok(())
     }
 
+    /// Return names of all visible (non-hidden) words, newest first.
+    pub fn visible_words(&self) -> Vec<String> {
+        let mut names = Vec::new();
+        let mut addr = self.latest;
+        while addr != 0 {
+            let flags_byte = self.memory[(addr + 4) as usize];
+            if flags_byte & flags::HIDDEN == 0 {
+                let name_len = (flags_byte & flags::LENGTH_MASK) as usize;
+                let name_start = (addr + 5) as usize;
+                let name = String::from_utf8_lossy(&self.memory[name_start..name_start + name_len])
+                    .to_string();
+                names.push(name);
+            }
+            let link = self.read_u32_unchecked(addr);
+            if link == addr {
+                break;
+            }
+            addr = link;
+        }
+        names
+    }
+
     /// Get a reference to the raw memory buffer.
     pub fn memory(&self) -> &[u8] {
         &self.memory
diff --git a/crates/core/src/outer.rs b/crates/core/src/outer.rs
index ffe7735..bbbbbb9 100644
--- a/crates/core/src/outer.rs
+++ b/crates/core/src/outer.rs
@@ -2584,6 +2584,7 @@ impl<R: Runtime> ForthVM<R> {
 
         // -- Programming-Tools word set --
         self.register_n_to_r()?;
+        self.register_words()?;
 
         // -- Search-Order word set --
         self.register_search_order()?;
@@ -4704,6 +4705,7 @@ impl<R: Runtime> ForthVM<R> {
                         self.dictionary.set_current_wid(top);
                     }
                 }
+                40 => self.do_words(),
                 _ => {}
             }
         }
@@ -5328,6 +5330,16 @@ impl<R: Runtime> ForthVM<R> {
         Ok(())
     }
 
+    /// WORDS ( -- ) Print all visible dictionary words.
+    fn do_words(&mut self) {
+        let names = self.dictionary.visible_words();
+        let mut out = self.output.lock().unwrap();
+        for name in &names {
+            out.push_str(name);
+            out.push(' ');
+        }
+    }
+
     /// Register Search-Order word set words.
     fn register_search_order(&mut self) -> anyhow::Result<()> {
         // FORTH-WORDLIST ( -- wid )
@@ -5553,6 +5565,17 @@ impl<R: Runtime> ForthVM<R> {
         Ok(())
     }
 
+    /// Register WORDS for the Programming-Tools word set.
+    fn register_words(&mut self) -> anyhow::Result<()> {
+        let pending = Arc::clone(&self.pending_define);
+        let func: HostFn = Box::new(move |_ctx: &mut dyn HostAccess| {
+            pending.lock().unwrap().push(40); // WORDS action
+            Ok(())
+        });
+        self.register_host_primitive("WORDS", false, func)?;
+        Ok(())
+    }
+
     /// Register UNESCAPE, SUBSTITUTE, REPLACES for the String word set.
     fn register_string_substitution(&mut self) -> anyhow::Result<()> {
         // UNESCAPE ( c-addr1 u1 c-addr2 -- c-addr2 u2 )
@@ -7942,6 +7965,27 @@ mod tests {
         );
     }
 
+    // ===================================================================
+    // WORDS (Programming-Tools)
+    // ===================================================================
+
+    #[test]
+    fn test_words_lists_defined_words() {
+        let output = eval_output("WORDS");
+        // Should contain standard primitives
+        assert!(output.contains("DUP"));
+        assert!(output.contains("DROP"));
+        assert!(output.contains("SWAP"));
+        assert!(output.contains("+"));
+        assert!(output.contains("WORDS"));
+    }
+
+    #[test]
+    fn test_words_includes_user_defined() {
+        let output = eval_output(": MYTEST 42 ; WORDS");
+        assert!(output.contains("MYTEST"));
+    }
+
     // ===================================================================
     // Double DOES>: Forth 2012 WEIRD: W1 test
     // ===================================================================