diff --git a/boot.c b/boot.c
index 8cc082b..16f9b9a 100644
--- a/boot.c
+++ b/boot.c
@@ -286,24 +286,6 @@ int parse_string() {
     return string_lut_size++;
 }
 
-void rewind_string(int new_data) {
-    string_offset = string_lut[token_data];
-    token_data = new_data;
-    --string_lut_size;
-}
-
-void dedup_string() {
-    int last_string = string_lut_size - 1;
-    char* latest = string_table + string_lut[last_string];
-    for (int i = 0; i < last_string; i++) {
-        char* candidate = string_table + string_lut[i];
-        if (streq(candidate, latest)) {
-            rewind_string(i);
-            return;
-        }
-    }
-}
-
 char id_table[ID_TABLE_SIZE];
 int id_offset;
 int id_lut[ID_LUT_SIZE];
@@ -320,24 +302,27 @@ int parse_id(int ch) {
     return id_lut_size++;
 }
 
-void rewind_id(int new_data) {
-    id_offset = id_lut[token_data];
-    token_data = new_data;
-    --id_lut_size;
-}
-
-void dedup_id() {
-    int last_id = id_lut_size - 1;
-    char* latest = id_table + id_lut[last_id];
-    for (int i = 0; i < last_id; i++) {
-        char* candidate = id_table + id_lut[i];
+void dedup(char* table, int* lut, int* lut_size, int* offset) {
+    char* latest = table + lut[*lut_size - 1];
+    for (int i = 0; i < *lut_size - 1; i++) {
+        char* candidate = table + lut[i];
         if (streq(candidate, latest)) {
-            rewind_id(i);
+            *offset = lut[token_data];
+            --*lut_size;
+            token_data = i;
             return;
         }
     }
 }
 
+void dedup_string() {
+    dedup(string_table, string_lut, &string_lut_size, &string_offset);
+}
+
+void dedup_id() {
+    dedup(id_table, id_lut, &id_lut_size, &id_offset);
+}
+
 void parse_id_like(int ch) {
     token_type = TOKEN_ID;
     token_data = parse_id(ch);
@@ -370,7 +355,8 @@ void parse_id_like(int ch) {
         token_type = TOKEN_ENUM;
     }
     if (token_type != TOKEN_ID) {
-        rewind_id(0);
+        id_offset = id_lut[token_data];
+        --id_lut_size;
     } else {
         dedup_id();
     }