refactor: replace raw int priority with InjectionPriority enum

Author: ivan-magda

core/src/main/kotlin/dev/textmate/grammar/Grammar.kt

@@ -79,7 +79,7 @@ class Grammar(
             }
         }
 
-        result.sortBy { it.priority }
+        result.sortBy { it.priority.value }
         return result
     }
 

core/src/main/kotlin/dev/textmate/grammar/InjectionRule.kt

@@ -2,6 +2,16 @@ package dev.textmate.grammar
 
 import dev.textmate.grammar.rule.RuleId
 
+/** Injection priority parsed from the selector prefix (`L:` / `R:`). */
+internal enum class InjectionPriority(val value: Int) {
+    /** `L:` prefix — wins ties against normal rules at the same position. */
+    HIGH(-1),
+    /** No prefix — normal priority. */
+    DEFAULT(0),
+    /** `R:` prefix — loses ties against normal rules at the same position. */
+    LOW(1)
+}
+
 /**
  * A compiled injection rule: a scope selector matcher paired with a compiled rule and priority.
  * Plain class (not data class) — function-typed [matcher] has identity-based equals/hashCode on JVM.
@@ -11,8 +21,8 @@ internal class InjectionRule(
     val debugSelector: String,
     /** Returns true when the current scope stack matches this injection's target. */
     val matcher: ScopeMatcher,
-    /** Priority: -1 = L: (high, wins ties), 0 = default, 1 = R: (low). */
-    val priority: Int,
+    /** Injection priority parsed from selector prefix. */
+    val priority: InjectionPriority,
     /** Rule compiled into the host grammar's rule space. */
     val ruleId: RuleId
 )

core/src/main/kotlin/dev/textmate/grammar/InjectionSelectorParser.kt

@@ -9,7 +9,7 @@ internal typealias ScopeMatcher = (List<String>) -> Boolean
  */
 internal class MatcherWithPriority(
     val matcher: ScopeMatcher,
-    val priority: Int  // -1 = L: (high), 0 = default, 1 = R: (low)
+    val priority: InjectionPriority
 )
 
 /**
@@ -21,8 +21,8 @@ internal class MatcherWithPriority(
  *   "text, string, comment"    — OR: any of the three
  *   "source.js comment"        — AND: both must appear in order
  *   "source.js -comment"       — AND NOT
- *   "L:comment"                — high priority (priority = -1)
- *   "R:comment"                — low priority (priority = 1)
+ *   "L:comment"                — high priority
+ *   "R:comment"                — low priority
  */
 internal object InjectionSelectorParser {
 
@@ -47,13 +47,13 @@ internal object InjectionSelectorParser {
         fun parse(): List<MatcherWithPriority> {
             val results = mutableListOf<MatcherWithPriority>()
             while (token != null) {
-                var priority = 0
+                var priority = InjectionPriority.DEFAULT
                 val t = token
                 if (t != null && t.length == 2 && t[1] == ':') {
                     priority = when (t[0]) {
-                        'L' -> -1
-                        'R' -> 1
-                        else -> 0
+                        'L' -> InjectionPriority.HIGH
+                        'R' -> InjectionPriority.LOW
+                        else -> InjectionPriority.DEFAULT
                     }
                     advance()
                 }

core/src/main/kotlin/dev/textmate/grammar/tokenize/Tokenizer.kt

@@ -1,6 +1,7 @@
 package dev.textmate.grammar.tokenize
 
 import dev.textmate.grammar.Grammar
+import dev.textmate.grammar.InjectionPriority
 import dev.textmate.grammar.InjectionRule
 import dev.textmate.grammar.rule.BeginEndRule
 import dev.textmate.grammar.rule.BeginWhileRule
@@ -283,7 +284,7 @@ private fun matchInjections(
 ): MatchInjectionsResult? {
     var bestMatchStart = Int.MAX_VALUE
     var bestResult: MatchRuleResult? = null
-    var bestPriority = 0
+    var bestPriority = InjectionPriority.DEFAULT
 
     val scopes = stack.contentNameScopesList?.getScopeNames() ?: return null
 
@@ -312,7 +313,7 @@ private fun matchInjections(
 
     val result = bestResult ?: return null
     return MatchInjectionsResult(
-        priorityMatch = bestPriority == -1,
+        priorityMatch = bestPriority == InjectionPriority.HIGH,
         matchRuleResult = result
     )
 }

core/src/test/kotlin/dev/textmate/grammar/InjectionGrammarTest.kt

@@ -45,7 +45,7 @@ class InjectionGrammarTest {
 
         assertEquals(1, injections.size)
         assertEquals("comment", injections[0].debugSelector)
-        assertEquals(0, injections[0].priority)
+        assertEquals(InjectionPriority.DEFAULT, injections[0].priority)
     }
 
     @Test
@@ -72,7 +72,7 @@ class InjectionGrammarTest {
     }
 
     @Test
-    fun `getInjections L-priority injector has priority minus one`() {
+    fun `getInjections L-priority injector has HIGH priority`() {
         val hostRaw = RawGrammar(scopeName = "source.test", patterns = emptyList())
         val injectorRaw = RawGrammar(
             scopeName = "text.injector",
@@ -81,7 +81,7 @@ class InjectionGrammarTest {
         )
         val grammar = createRegistry(hostRaw, injectorRaw).loadGrammar("source.test")
             ?: error("Grammar 'source.test' not found")
-        assertEquals(-1, grammar.getInjections()[0].priority)
+        assertEquals(InjectionPriority.HIGH, grammar.getInjections()[0].priority)
     }
 
     @Test

core/src/test/kotlin/dev/textmate/grammar/InjectionSelectorParserTest.kt

@@ -63,23 +63,23 @@ class InjectionSelectorParserTest {
     // --- Priority ---
 
     @Test
-    fun `L prefix gives priority minus one`() {
+    fun `L prefix gives HIGH priority`() {
         val matchers = InjectionSelectorParser.createMatchers("L:comment")
         assertEquals(1, matchers.size)
-        assertEquals(-1, matchers[0].priority)
+        assertEquals(InjectionPriority.HIGH, matchers[0].priority)
     }
 
     @Test
-    fun `R prefix gives priority one`() {
+    fun `R prefix gives LOW priority`() {
         val matchers = InjectionSelectorParser.createMatchers("R:comment")
         assertEquals(1, matchers.size)
-        assertEquals(1, matchers[0].priority)
+        assertEquals(InjectionPriority.LOW, matchers[0].priority)
     }
 
     @Test
-    fun `no prefix gives priority zero`() {
+    fun `no prefix gives DEFAULT priority`() {
         val matchers = InjectionSelectorParser.createMatchers("comment")
-        assertEquals(0, matchers[0].priority)
+        assertEquals(InjectionPriority.DEFAULT, matchers[0].priority)
     }
 
     // --- Edge cases ---