From 438a90fa4fc4d488ffcae6bba3fa12e0180aeed1 Mon Sep 17 00:00:00 2001
From: Eddie Antonio Santos <easantos@ualberta.ca>
Date: Mon, 27 Apr 2020 16:19:25 -0600
Subject: [PATCH] feat(common/lmlayer): compile join decorator

---
 .../lexical-model-compiler/lexical-model-compiler.ts   | 10 +++++++++-
 .../js/source/lexical-model-compiler/lexical-model.ts  |  7 +++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/developer/js/source/lexical-model-compiler/lexical-model-compiler.ts b/developer/js/source/lexical-model-compiler/lexical-model-compiler.ts
index 6ff0b36db5..29aa435e15 100644
--- a/developer/js/source/lexical-model-compiler/lexical-model-compiler.ts
+++ b/developer/js/source/lexical-model-compiler/lexical-model-compiler.ts
@@ -93,11 +93,19 @@ export class ModelSourceError extends Error {
  * breaking function.
  */
 function compileWordBreaker(spec: WordBreakerSpec): string {
-  return compileInnerWordBreaker(spec.use);
+  let baseWordBreakerCode = compileInnerWordBreaker(spec.use);
+
+  if (spec.joinWordsAt == undefined) {
+    // No need to decorate; return it as-is
+    return baseWordBreakerCode;
+  }
+  // Let's decorate it with the join word breaker!
+  return `wordBreakers.join_(${baseWordBreakerCode},${JSON.stringify(spec.joinWordsAt)})`;
 }
 
 /**
  * Compiles the base word breaker, that may be decorated later.
+ * Returns the source code of a JavaScript expression.
  */
 function compileInnerWordBreaker(spec: SimpleWordBreakerSpec): string {
   if (typeof spec === "string") {
diff --git a/developer/js/source/lexical-model-compiler/lexical-model.ts b/developer/js/source/lexical-model-compiler/lexical-model.ts
index b705ced2fa..f1767cd8de 100644
--- a/developer/js/source/lexical-model-compiler/lexical-model.ts
+++ b/developer/js/source/lexical-model-compiler/lexical-model.ts
@@ -17,6 +17,13 @@ interface LexicalModelDeclaration {
  */
 interface WordBreakerSpec {
   readonly use: SimpleWordBreakerSpec;
+  /**
+   * If present, joins words that were split by the word breaker
+   * together at the given strings. e.g.,
+   *
+   *    joinWordsAt: ['-'] // to keep hyphenated items together
+   */
+  readonly joinWordsAt?: string[];
 }
 
 /**