diff --git a/docs/Iterable.md b/docs/Iterable.md
index 80cff82..30e0070 100644
--- a/docs/Iterable.md
+++ b/docs/Iterable.md
@@ -40,13 +40,13 @@ available, for example
 ## joinToString
 
 This methods convert any iterable to a string joining string representation of each element, optionally transforming it
-and joining using specified suffix.
+and joining using specified separator.
 
-    Iterable.joinToString(suffux=' ', transform=null)
+    Iterable.joinToString(separator=' ', transformer=null)
 
 - if `Iterable` `isEmpty`, the empty string `""` is returned.
-- `suffix` is inserted between items when there are more than one.
-- `transform` of specified is applied to each element, otherwise its `toString()` method is used.
+- `separator` is inserted between items when there are more than one.
+- `transformer` of specified is applied to each element, otherwise its `toString()` method is used.
 
 Here is the sample:
 
@@ -104,7 +104,7 @@ Search for the first element that satisfies the given predicate:
 | toList()               | create a list from iterable                                                     |
 | toSet()                | create a set from iterable                                                      |
 | contains(i)            | check that iterable contains `i`                                                |
-| `i in iterator`        | same as `contains(i)`                                                           |
+| `i in iterable`        | same as `contains(i)`                                                           |
 | isEmpty()              | check iterable is empty                                                         |
 | forEach(f)             | call f for each element                                                         |
 | toMap()                | create a map from list of key-value pairs (arrays of 2 items or like)           |
@@ -116,7 +116,7 @@ Search for the first element that satisfies the given predicate:
 | first                  | first element (1)                                                               |
 | last                   | last element (1)                                                                |
 | take(n)                | return [Iterable] of up to n first elements                                     |
-| taleLast(n)            | return [Iterable] of up to n last elements                                      |
+| takeLast(n)            | return [Iterable] of up to n last elements                                      |
 | drop(n)                | return new [Iterable] without first n elements                                  |
 | dropLast(n)            | return new [Iterable] without last n elements                                   |
 | sum()                  | return sum of the collection applying `+` to its elements (3)                   |
@@ -129,32 +129,19 @@ Search for the first element that satisfies the given predicate:
 | shuffled()             | create a listof shiffled elements                                               |
 
 (1)
-: throws `NoSuchElementException` if there is no such element
+:: throws `NoSuchElementException` if there is no such element
 
 (2)
-: `joinToString(suffix=" ",transform=null)`: suffix is inserted between items if there are more than one, trasnfom is
+:: `joinToString(separator=" ", transformer=null)`: separator is inserted between items if there are more than one, transformer is
 optional function applied to each item that must return result string for an item, otherwise `item.toString()` is used.
 
 (3)
-: sum of empty collection is `null`
-
-    fun Iterable.toList(): List
-    fun Iterable.toSet(): Set
-    fun Iterable.indexOf(element): Int
-    fun Iterable.contains(element): Bool
-    fun Iterable.isEmpty(element): Bool
-    fun Iterable.forEach(block: (Any?)->Void ): Void
-    fun Iterable.map(block: (Any?)->Void ): List
-    fun Iterable.associateBy( keyMaker: (Any?)->Any): Map
-    fun Iterable.findFirst( predicate: (Any?)->Bool): Any
-    fun Iterable.findFirstOrNull( predicate: (Any?)->Bool): Any?
+:: sum of empty collection is `null`
 
 ## Abstract methods:
 
     fun iterator(): Iterator
 
-Creates a list by iterating to the end. So, the Iterator should be finite to be used with it.
-
 ## Included in interfaces:
 
 - [Collection], Array, [List]
diff --git a/lynglib/stdlib/lyng/root.lyng b/lynglib/stdlib/lyng/root.lyng
index 8f22b52..0a910a5 100644
--- a/lynglib/stdlib/lyng/root.lyng
+++ b/lynglib/stdlib/lyng/root.lyng
@@ -20,7 +20,7 @@ fun Iterable.filter(predicate) {
     val list = this
     flow {
         for( item in list ) {
-            if( predicate(item) ) {ln
+            if( predicate(item) ) {
                 emit(item)
             }
         }
@@ -96,13 +96,13 @@ fun Iterable.takeLast(n) {
     buffer
 }
 
-/* Join elements into a string with a separator (prefix parameter) and optional transformer. */
-fun Iterable.joinToString(prefix=" ", transformer=null) {
+/* Join elements into a string with a separator (separator parameter) and optional transformer. */
+fun Iterable.joinToString(separator=" ", transformer=null) {
     var result = null
     for( part in this ) {
         val transformed = transformer?(part)?.toString() ?: part.toString()
         if( result == null ) result = transformed
-        else result += prefix + transformed
+        else result += separator + transformed
     }
     result ?: ""
 }
diff --git a/lyngweb/src/jsMain/kotlin/net/sergeych/lyngweb/Highlight.kt b/lyngweb/src/jsMain/kotlin/net/sergeych/lyngweb/Highlight.kt
index 5ac8579..333f0ac 100644
--- a/lyngweb/src/jsMain/kotlin/net/sergeych/lyngweb/Highlight.kt
+++ b/lyngweb/src/jsMain/kotlin/net/sergeych/lyngweb/Highlight.kt
@@ -411,6 +411,7 @@ suspend fun applyLyngHighlightToTextAst(text: String): String {
         try {
             if (mini != null) {
                 val binding = Binder.bind(text, mini)
+                val symbolsById = binding.symbols.associateBy { it.id }
                 // Map decl ranges to avoid overriding declarations
                 val declKeys = HashSet<Pair<Int, Int>>()
                 for (sym in binding.symbols) {
@@ -427,7 +428,7 @@ suspend fun applyLyngHighlightToTextAst(text: String): String {
                     val key = ref.start to ref.end
                     if (declKeys.contains(key)) continue
                     if (!overrides.containsKey(key)) {
-                        val sym = binding.symbols.firstOrNull { it.id == ref.symbolId }
+                        val sym = symbolsById[ref.symbolId]
                         val cls = sym?.let { classForKind(it.kind) }
                         if (cls != null) overrides[key] = cls
                     }