feat(parser): add PUBLISH/SUBSCRIBE/UNSUBSCRIBE and DEFINE EVENT parsing

CLAUDE.md

@@ -96,14 +96,14 @@ Defines AST nodes for the parser. Key types:
 Parses ABL source code into an AST. Key capabilities:
 
 - **Expression parsing** with proper operator precedence (ternary → or → and → comparison → additive → multiplicative → unary → postfix → primary)
-- **Statement parsing**: DEFINE VARIABLE/VAR/PARAMETER/TEMP-TABLE/BUFFER/PROPERTY/STREAM/FRAME, DO blocks (with counting loops), IF/THEN/ELSE, REPEAT, FOR EACH, FIND, CASE, PROCEDURE, FUNCTION, RUN, DISPLAY (with STREAM clause), MESSAGE, ASSIGN, CREATE, DELETE, RELEASE, VALIDATE, BUFFER-COPY, BUFFER-COMPARE, INPUT/OUTPUT/INPUT-OUTPUT stream I/O (FROM/TO/THROUGH/CLOSE), CATCH/FINALLY/THROW, LEAVE, NEXT, RETURN
+- **Statement parsing**: DEFINE VARIABLE/VAR/PARAMETER/TEMP-TABLE/BUFFER/PROPERTY/STREAM/FRAME/EVENT, DO blocks (with counting loops), IF/THEN/ELSE, REPEAT, FOR EACH, FIND, CASE, PROCEDURE, FUNCTION, RUN, DISPLAY (with STREAM clause), MESSAGE, ASSIGN, CREATE, DELETE, RELEASE, VALIDATE, BUFFER-COPY, BUFFER-COMPARE, INPUT/OUTPUT/INPUT-OUTPUT stream I/O (FROM/TO/THROUGH/CLOSE), CATCH/FINALLY/THROW, PUBLISH/SUBSCRIBE/UNSUBSCRIBE, LEAVE, NEXT, RETURN
 - **OO-ABL**: CLASS (with ABSTRACT/FINAL, INHERITS, IMPLEMENTS), INTERFACE, METHOD (with access modifiers, STATIC/ABSTRACT/OVERRIDE), DEFINE PROPERTY (auto and computed GET/SET), CONSTRUCTOR, DESTRUCTOR, USING
 - **Postfix operations**: Method calls (object:method()), member access (object.member), array access (arr[i]), field access (table.field)
 - **Function calls** with argument lists
 - **Preprocessor**: &IF/&ELSEIF/&ELSE/&ENDIF at statement, expression, and data type levels via generic `PreprocIf<T>`, &SCOPED-DEFINE/&GLOBAL-DEFINE with `PreprocEnd` lexer token, &UNDEFINE, &MESSAGE, `{&variable}` references
 - **Error recovery** via `parse_program()` with synchronization on period boundaries
 
-Not yet implemented: DATASET, PUBLISH/SUBSCRIBE, ON triggers.
+Not yet implemented: ON triggers.
 
 ### Code Generation (`oxabl_codegen`)
 

crates/oxabl_ast/src/statement.rs

@@ -453,6 +453,55 @@ pub enum Statement {
         source_buffers: Vec<DataSourceBuffer>,
     },
 
+    /// PUBLISH event-name [FROM publisher-handle] [(args...)].
+    Publish {
+        /// Event name — string literal or character expression.
+        event_name: Expression,
+        /// Optional FROM publisher-handle.
+        from_handle: Option<Expression>,
+        /// Arguments passed to subscribers (reuses RunArgument).
+        arguments: Vec<RunArgument>,
+    },
+
+    /// SUBSCRIBE [PROCEDURE subscriber-handle] [TO] event-name {IN handle | ANYWHERE}
+    ///   [RUN-PROCEDURE handler-name] [NO-ERROR].
+    Subscribe {
+        /// Optional PROCEDURE subscriber-handle.
+        subscriber: Option<Expression>,
+        /// Event name — string literal or character expression.
+        event_name: Expression,
+        /// IN publisher-handle or ANYWHERE (required).
+        target: SubscribeTarget,
+        /// Optional RUN-PROCEDURE handler name.
+        run_procedure: Option<Identifier>,
+        /// Whether NO-ERROR was specified.
+        no_error: bool,
+    },
+
+    /// UNSUBSCRIBE [PROCEDURE subscriber-handle] [TO] {event-name | ALL} [IN publisher-handle].
+    Unsubscribe {
+        /// Optional PROCEDURE subscriber-handle.
+        subscriber: Option<Expression>,
+        /// Event name, or None if ALL was specified.
+        event_name: Option<Expression>,
+        /// Optional IN publisher-handle.
+        in_handle: Option<Expression>,
+    },
+
+    /// DEFINE [access] [STATIC] [ABSTRACT] EVENT event-name SIGNATURE VOID (params...).
+    DefineEvent {
+        /// Access modifier (defaults to PUBLIC).
+        access: AccessModifier,
+        /// Whether STATIC was specified.
+        is_static: bool,
+        /// Whether ABSTRACT was specified.
+        is_abstract: bool,
+        /// Event name.
+        name: Identifier,
+        /// Signature parameters (reuses DefineParameter via Vec<Statement>).
+        parameters: Vec<Statement>,
+    },
+
     /// INPUT/OUTPUT/INPUT-OUTPUT stream I/O statement.
     StreamIo {
         direction: StreamDirection,
@@ -803,3 +852,16 @@ pub struct HandlePassingOptions {
     pub bind: bool,
     pub by_value: bool,
 }
+
+// =============================================================================
+// Event system types
+// =============================================================================
+
+/// Target for SUBSCRIBE — where to listen for events.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum SubscribeTarget {
+    /// Subscribe to events from a specific publisher handle.
+    InHandle(Expression),
+    /// Subscribe to events from any publisher.
+    Anywhere,
+}

crates/oxabl_lexer/build.rs

@@ -62,6 +62,7 @@ fn main() {
             "analyze",
             "and",
             "any",
+            "anywhere",
             "append",
             "apply",
             "as",
@@ -208,6 +209,7 @@ fn main() {
             "error status",
             "escape",
             "etime",
+            "event",
             "event procedure",
             "except",
             "exclusive-lock",
@@ -464,6 +466,7 @@ fn main() {
             "provers",
             "proversion",
             "public",
+            "publish",
             "put",
             "put-byte",
             "put-key-val",
@@ -502,6 +505,7 @@ fn main() {
             "revoke",
             "rowid",
             "run",
+            "run-procedure",
             "save",
             "sax-comple",
             "sax-complete",
@@ -540,6 +544,7 @@ fn main() {
             "shared",
             "show-stat",
             "show-stats",
+            "signature",
             "single-run",
             "skip",
             "skip-deleted-record",
@@ -550,6 +555,7 @@ fn main() {
             "stream",
             "stream-handle",
             "stream-io",
+            "subscribe",
             "system-dialog",
             "table",
             "table-handle",
@@ -584,6 +590,7 @@ fn main() {
             "union",
             "unique",
             "unix",
+            "unsubscribe",
             "up",
             "update",
             "use-index",

crates/oxabl_lexer/src/kind.rs

@@ -156,6 +156,9 @@ pub enum Kind {
     BufferCompare,
     Close,
     ParentIdRelation,
+    Publish,
+    Subscribe,
+    Unsubscribe,
 
     // Functions
     Accum,
@@ -316,6 +319,10 @@ pub enum Kind {
     TableHandle,
     Bind,
     ByValue,
+    Anywhere,
+    Event,
+    Signature,
+    RunProcedure,
 
     // Phrases
     Editing,
@@ -762,6 +769,7 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "displ" => Some(Kind::Display),
             "entry" => Some(Kind::Entry),
             "etime" => Some(Kind::Etime),
+            "event" => Some(Kind::Event),
             "false" => Some(Kind::KwFalse),
             "fetch" => Some(Kind::Fetch),
             "field" => Some(Kind::Field),
@@ -989,6 +997,7 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "promsgs" => Some(Kind::Promsgs),
             "propath" => Some(Kind::Propath),
             "provers" => Some(Kind::Proversion),
+            "publish" => Some(Kind::Publish),
             "putbyte" => Some(Kind::Putbyte),
             "r-index" => Some(Kind::RIndex),
             "readkey" => Some(Kind::Readkey),
@@ -1018,6 +1027,7 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "abstract" => Some(Kind::Abstract),
             "accumula" => Some(Kind::Accumulate),
             "ambiguou" => Some(Kind::Ambiguous),
+            "anywhere" => Some(Kind::Anywhere),
             "ascendin" => Some(Kind::Ascending),
             "attr spa" => Some(Kind::AttrSpace),
             "attr-spa" => Some(Kind::AttrSpace),
@@ -1192,7 +1202,9 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "screen-io" => Some(Kind::ScreenIo),
             "setuserid" => Some(Kind::Setuserid),
             "show-stat" => Some(Kind::ShowStats),
+            "signature" => Some(Kind::Signature),
             "stream-io" => Some(Kind::StreamIo),
+            "subscribe" => Some(Kind::Subscribe),
             "underline" => Some(Kind::Underline),
             "unformatt" => Some(Kind::Unformatted),
             "use-index" => Some(Kind::UseIndex),
@@ -1349,6 +1361,7 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "thread-safe" => Some(Kind::ThreadSafe),
             "transaction" => Some(Kind::Transaction),
             "unformatted" => Some(Kind::Unformatted),
+            "unsubscribe" => Some(Kind::Unsubscribe),
             "widget-pool" => Some(Kind::WidgetPool),
             _ => None,
         },
@@ -1432,6 +1445,7 @@ pub fn match_keyword(s: &str) -> Option<Kind> {
             "put-key-value" => Some(Kind::PutKeyValue),
             "query-off-end" => Some(Kind::QueryOffEnd),
             "rcode-informa" => Some(Kind::RcodeInformation),
+            "run-procedure" => Some(Kind::RunProcedure),
             "sax-write-tag" => Some(Kind::SaxWriteTag),
             "search-targer" => Some(Kind::SearchTarger),
             "stream-handle" => Some(Kind::StreamHandle),

crates/oxabl_parser/src/parser/mod.rs

@@ -271,6 +271,14 @@ impl<'a> Parser<'a> {
                     | Kind::ByValue
                     | Kind::Query
                     | Kind::Reposition
+                    // Event system keywords (unreserved)
+                    | Kind::Publish
+                    | Kind::Subscribe
+                    | Kind::Unsubscribe
+                    | Kind::Anywhere
+                    | Kind::Event
+                    | Kind::Signature
+                    | Kind::RunProcedure
             )
     }