C#: Address review comments

csharp/ql/src/semmle/code/csharp/dataflow/LibraryTypeDataFlow.qll

@@ -163,7 +163,7 @@ class CallableFlowSink extends TCallableFlowSink {
   Expr getSink(Call c) { none() }
 
   /**
-   * Gets the type of the sink for call `c`. Unlik `getSink()`, this is defined
+   * Gets the type of the sink for call `c`. Unlike `getSink()`, this is defined
    * for all flow sink specifications.
    */
   Type getSinkType(Call c) { result = this.getSink(c).getType() }
@@ -235,18 +235,22 @@ private CallableFlowSinkDelegateArg getDelegateFlowSinkArg(
 
 /** A flow sink specification: parameter of a delegate argument. */
 class CallableFlowSinkDelegateArg extends CallableFlowSink, TCallableFlowSinkDelegateArg {
-  private int i;
-  private int j;
+  private int delegateIndex;
+  private int parameterIndex;
 
-  CallableFlowSinkDelegateArg() { this = TCallableFlowSinkDelegateArg(i, j) }
+  CallableFlowSinkDelegateArg() {
+    this = TCallableFlowSinkDelegateArg(delegateIndex, parameterIndex)
+  }
 
   /** Gets the index of the delegate argument. */
-  int getDelegateIndex() { result = i }
+  int getDelegateIndex() { result = delegateIndex }
 
   /** Gets the index of the delegate parameter. */
-  int getDelegateParameterIndex() { result = j }
+  int getDelegateParameterIndex() { result = parameterIndex }
 
-  override string toString() { result = "parameter " + j + " of argument " + i }
+  override string toString() {
+    result = "parameter " + parameterIndex + " of argument " + delegateIndex
+  }
 
   override Expr getSink(Call c) {
     // The uses of the `j`th parameter are the actual sinks
@@ -256,10 +260,10 @@ class CallableFlowSinkDelegateArg extends CallableFlowSink, TCallableFlowSinkDel
   override Type getSinkType(Call c) {
     result =
       c
-          .getArgument(i)
+          .getArgument(delegateIndex)
           .(DelegateArgumentToLibraryCallable)
           .getDelegateType()
-          .getParameter(j)
+          .getParameter(parameterIndex)
           .getType()
   }
 }

csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -860,25 +860,29 @@ private module ArgumentNodes {
    */
   class ImplicitDelegateArgumentNode extends ArgumentNode, TImplicitDelegateArgumentNode {
     private ControlFlow::Node cfn;
-    private int i;
-    private int j;
+    private int delegateIndex;
+    private int parameterIndex;
 
-    ImplicitDelegateArgumentNode() { this = TImplicitDelegateArgumentNode(cfn, i, j) }
+    ImplicitDelegateArgumentNode() {
+      this = TImplicitDelegateArgumentNode(cfn, delegateIndex, parameterIndex)
+    }
 
     private ImplicitDelegateDataFlowCall getDelegateCall() { result.getControlFlowNode() = cfn }
 
     override predicate argumentOf(DataFlowCall call, int pos) {
       call = this.getDelegateCall() and
-      pos = j
+      pos = parameterIndex
     }
 
     override Callable getEnclosingCallable() { result = cfn.getEnclosingCallable() }
 
-    override Type getType() { result = this.getDelegateCall().getDelegateParameterType(j) }
+    override Type getType() {
+      result = this.getDelegateCall().getDelegateParameterType(parameterIndex)
+    }
 
     override Location getLocation() { result = cfn.getLocation() }
 
-    override string toString() { result = "[implicit argument " + j + "] " + cfn }
+    override string toString() { result = "[implicit argument " + parameterIndex + "] " + cfn }
   }
 }
 
@@ -1332,8 +1336,8 @@ class LibraryCodeNode extends Node, TLibraryCodeNode {
   predicate preservesValue() { preservesValue = true }
 
   /**
-   * Gets the predecessor of this library-code node. `ap` describes the content
-   * that is read from when entering this node (if any).
+   * Gets the predecessor of this library-code node. The head of `ap` describes
+   * the content that is read from when entering this node (if any).
    */
   Node getPredecessor(AccessPath ap) {
     ap = sourceAp and
@@ -1352,8 +1356,8 @@ class LibraryCodeNode extends Node, TLibraryCodeNode {
   }
 
   /**
-   * Gets the successor of this library-code node. `ap` describes the content that
-   * is stored into when leaving this node (if any).
+   * Gets the successor of this library-code node. The head of `ap` describes
+   * the content that is stored into when leaving this node (if any).
    */
   Node getSuccessor(AccessPath ap) {
     ap = sinkAp and

csharp/ql/src/semmle/code/csharp/dataflow/internal/DelegateDataFlow.qll

@@ -119,7 +119,7 @@ library class DelegateArgumentToLibraryCallable extends Expr {
   Call getCall() { result = call }
 
   /** Gets the index of this delegate argument in the call. */
-  int getArgumentIndex() { this.getCall().getArgument(result) = this }
+  int getArgumentIndex() { this = this.getCall().getArgument(result) }
 
   /** Gets the delegate type of this argument. */
   DelegateType getDelegateType() { result = dt }

csharp/ql/test/library-tests/dataflow/library/LibraryTypeDataFlow.expected

@@ -1683,7 +1683,7 @@ callableFlow
 | System.Web.HttpUtility.HtmlEncode(string) | argument 0 -> return | false |
 | System.Web.HttpUtility.UrlEncode(string) | argument 0 -> return | false |
 | System.Web.UI.WebControls.TextBox.get_Text() | qualifier -> return | false |
-callableFlowAp
+callableFlowAccessPath
 | System.Lazy<>.Lazy(Func<T>) | output from argument 0 [<empty>] -> return [Value] |
 | System.Lazy<>.Lazy(Func<T>, LazyThreadSafetyMode) | output from argument 0 [<empty>] -> return [Value] |
 | System.Lazy<>.Lazy(Func<T>, bool) | output from argument 0 [<empty>] -> return [Value] |

csharp/ql/test/library-tests/dataflow/library/LibraryTypeDataFlow.ql

@@ -13,7 +13,7 @@ query predicate callableFlow(string callable, string flow, boolean preservesValu
   )
 }
 
-query predicate callableFlowAp(string callable, string flow) {
+query predicate callableFlowAccessPath(string callable, string flow) {
   exists(
     LibraryTypeDataFlow x, CallableFlowSource source, AccessPath sourceAp, CallableFlowSink sink,
     AccessPath sinkAp, Callable c