safe SearchContext.index

Author: tangzx

src/main/java/com/tang/intellij/lua/psi/LuaPsiImplUtil.kt

@@ -264,14 +264,15 @@ fun guessTypeAt(list: LuaExprList, context: SearchContext): ITy {
         //local a, b = getValues12() -- a = 1, b = 2
         //local a, b, c = getValues12(), 3, 4 --a = 1, b = 3, c =  4
         //local a, b, c = getValues12(), getValue34() --a = 1, b = 3, c =  4
+        var index = -1
         if (exprList.size > 1) {
             val nameSize = context.index + 1
-            if (nameSize > exprList.size) {
+            index = if (nameSize > exprList.size) {
                 val valueSize = exprList.size
-                context.index = nameSize - valueSize
-            } else context.index = 0
+                nameSize - valueSize
+            } else 0
         }
-        return expr.guessType(context)
+        return context.withIndex(index) { expr.guessType(context) }
     }
     return Ty.UNKNOWN
 }
@@ -353,8 +354,9 @@ fun guessValueType(indexExpr: LuaIndexExpr, context: SearchContext): ITy {
     var ret: ITy = Ty.UNKNOWN
     val assignStat = indexExpr.assignStat
     if (assignStat != null) {
-        context.index = assignStat.getIndexFor(indexExpr)
-        ret = assignStat.valueExprList?.guessTypeAt(context) ?: Ty.UNKNOWN
+        ret = context.withIndex(assignStat.getIndexFor(indexExpr)) {
+            assignStat.valueExprList?.guessTypeAt(context) ?: Ty.UNKNOWN
+        }
     }
     return ret
 }
@@ -576,11 +578,12 @@ fun guessReturnType(returnStat: LuaReturnStat?, index: Int, context: SearchConte
     if (returnStat != null) {
         val returnExpr = returnStat.exprList
         if (returnExpr != null) {
-            context.index = index
-            return if (context.guessTuple())
-                returnExpr.guessType(context)
-            else
-                returnExpr.guessTypeAt(context)
+            return context.withIndex(index) {
+                if (context.guessTuple())
+                    returnExpr.guessType(context)
+                else
+                    returnExpr.guessTypeAt(context)
+            }
         }
     }
     return Ty.UNKNOWN

src/main/java/com/tang/intellij/lua/search/SearchContext.kt

@@ -34,10 +34,16 @@ class SearchContext(val project: Project, private val currentFile: PsiFile? = nu
     /**
      * 用于有多返回值的索引设定
      */
-    var index: Int = -1
+    val index: Int get() = myIndex
 
-    fun resetIndex() {
-        index = -1
+    private var myIndex: Int = -1
+
+    fun <T> withIndex(index: Int, action: () -> T): T {
+        val savedIndex = this.index
+        myIndex = index
+        val ret = action()
+        myIndex = savedIndex
+        return ret
     }
 
     fun guessTuple() = index < 0

src/main/java/com/tang/intellij/lua/ty/Declarations.kt

@@ -136,8 +136,9 @@ private fun LuaNameDef.infer(context: SearchContext): ITy {
                 val nameList = localDef.nameList
                 val exprList = localDef.exprList
                 if (nameList != null && exprList != null) {
-                    context.index = localDef.getIndexFor(this)
-                    type = exprList.guessTypeAt(context)
+                    type = context.withIndex(localDef.getIndexFor(this)) {
+                        exprList.guessTypeAt(context)
+                    }
                 }
             }
 

src/main/java/com/tang/intellij/lua/ty/Expressions.kt

@@ -254,8 +254,9 @@ private fun getType(context: SearchContext, def: PsiElement): ITy {
                 if (stat != null) {
                     val exprList = stat.valueExprList
                     if (exprList != null) {
-                        context.index = stat.getIndexFor(def)
-                        type = exprList.guessTypeAt(context)
+                        type = context.withIndex(stat.getIndexFor(def)) {
+                            exprList.guessTypeAt(context)
+                        }
                     }
                 }
             }
@@ -323,10 +324,7 @@ private fun LuaIndexExpr.infer(context: SearchContext): ITy {
         //from other class member
         val propName = indexExpr.name
         if (propName != null) {
-            // 查找 parent 定义时不应该影响当前index
-            val saveIdx = context.index
             val prefixType = indexExpr.guessParentType(context)
-            context.index = saveIdx
 
             prefixType.eachTopClass(Processor {
                 result = result.union(guessFieldType(propName, it, context))