From 32541d47946478b6fd784a10cba495dd83b696a3 Mon Sep 17 00:00:00 2001
From: venko <alexmflores@gmail.com>
Date: Sat, 8 May 2021 15:12:53 -0700
Subject: [PATCH] Fixes bugs in LookupId

---
 src/identcheck.c | 26 +++++++++++++++++++++-----
 src/main.c       |  4 ++--
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/src/identcheck.c b/src/identcheck.c
index e8a51c1..c1c56e9 100644
--- a/src/identcheck.c
+++ b/src/identcheck.c
@@ -238,23 +238,39 @@ IdNode* LookupId(IdNode *node, IdNode *prev, char *target) {
         return node;
     }
 
-    // If the current node forms an ordered scope then we want to prevent ourselves from looking up
-    // identifiers declared after the scope we have just come from.
+    // If this is the start of our search, we should not attempt to look at child nodes. Only
+    // looking up the scope tree is valid at this point.
+    //
+    // This has the notable side-effect that this function will return NULL if you attempt to look
+    // up a struct's internals starting from the node representing the struct itself. This is
+    // because an IdNode corresponds to the location *where an identifier is first declared.* Thus,
+    // an identifier has no knowledge of identifiers declared "inside" of it.
+    if (prev == NULL) {
+        return LookupId(node->parent, node, target);
+    }
+
     uint32_t idxLimit;
-    if (prev == NULL || !ScopeHasOrdering(node)) {
-        idxLimit = node->childCount;
-    } else {
+    // If the current node forms an ordered scope then we want to prevent ourselves from looking
+    // up identifiers declared after the scope we have just come from.
+    if (ScopeHasOrdering(node)) {
         uint32_t i;
         for (i = 0, idxLimit = 0; i < node->childCount; i++, idxLimit++) {
             if (node->children[i] == prev) {
                 break;
             }
         }
+    } else {
+        idxLimit = node->childCount;
     }
 
     uint32_t i;
     for (i = 0; i < idxLimit; i++) {
         IdNode *child = node->children[i];
+        if (child == prev) {
+            // Do not inspect the node we just came from.
+            continue;
+        }
+
         if (strcmp(child->name, target) == 0) {
             return child;
         } 
diff --git a/src/main.c b/src/main.c
index d50aeb5..cd1fbbb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -69,8 +69,8 @@ int main(int argc, char *argv[])
                         IdNode *idTree = MakeIdTree(rootNode, NULL);
                         PrintIdTree(idTree, /*tabCount=*/0);
 
-                        printf("\nSeeking to variable 'myStructInt'\n");
-                        IdNode *node = LookdownId(idTree, Variable, "myStructInt");
+                        printf("\nSeeking to struct 'Program'\n");
+                        IdNode *node = LookdownId(idTree, Struct, "Program");
                         if (node == NULL) printf("Failed.\n");
 
                         printf("\n[attempting to look up MyStruct]: \n");