diff --git a/src/cbor/diagnostic.cr b/src/cbor/diagnostic.cr
index c86cead..a88c946 100644
--- a/src/cbor/diagnostic.cr
+++ b/src/cbor/diagnostic.cr
@@ -1,6 +1,3 @@
-require "./lexer"
-require "./token"
-
 # Reads a CBOR input into a diagnostic string.
 # This consumes the IO and is mostly usedful to tests again the example
 # provided in the RFC and ensuring a correct functioning of the `CBOR::Lexer`.
@@ -29,15 +26,48 @@ class CBOR::Diagnostic
     when Kind::Int
       token.value.to_s
     when Kind::String
-      %("#{token.value.as(String)}")
+      if token.chunks
+        chunks = chunks(token.value.as(String), token.chunks.as(Array(Int32)))
+        "(_ #{chunks.map { |s| string(s) }.join(", ")})"
+      else
+        string(token.value.as(String))
+      end
     when Kind::Bytes
-      "h'#{token.value.as(Bytes).hexstring}'"
-    when Kind::BytesArray
-      token.value.as(BytesArray).to_diagnostic
-    when Kind::StringArray
-      token.value.as(StringArray).to_diagnostic
+      if token.chunks
+        chunks = chunks(token.value.as(Bytes), token.chunks.as(Array(Int32)))
+        "(_ #{chunks.map { |b| bytes(b) }.join(", ")})"
+      else
+        bytes(token.value.as(Bytes))
+      end
     else
       token.kind.to_s
     end
   end
+
+  private def chunks(value : Bytes, chunks : Array(Int32)) : Array(Bytes)
+    res = Array(Bytes).new
+    bytes = value.to_a
+    chunks.each do |size|
+      bytes_chunk = bytes.shift(size)
+      res << Bytes.new(bytes_chunk.to_unsafe, bytes_chunk.size)
+    end
+    res
+  end
+
+  private def chunks(value : String, chunks : Array(Int32)) : Array(String)
+    res = Array(String).new
+    arr = value.split("")
+    chunks.each do |size|
+      res << arr.shift(size).join
+    end
+    res
+  end
+
+  private def bytes(b : Bytes) : String
+    "h'#{b.hexstring}'"
+  end
+
+  private def string(s : String) : String
+    %("#{s}")
+  end
 end
diff --git a/src/cbor/lexer.cr b/src/cbor/lexer.cr
index 4864628..c529f64 100644
--- a/src/cbor/lexer.cr
+++ b/src/cbor/lexer.cr
@@ -1,25 +1,4 @@
-require "./token"
-
 class CBOR::Lexer
-  # Types returned by the lexer
-  alias Type = Nil |
-               Bool |
-               String |
-               Bytes |
-               Array(CBOR::Type) |
-               Hash(CBOR::Type, CBOR::Type) |
-               Int8 |
-               UInt8 |
-               Int16 |
-               UInt16 |
-               Int32 |
-               UInt32 |
-               Int64 |
-               UInt64 |
-               Int128 |
-               BytesArray |
-               StringArray
-
   def self.new(string : String)
     new IO::Memory.new(string)
   end
@@ -65,32 +44,57 @@ class CBOR::Lexer
          Kind::Undefined
       Token.new(kind: token.kind, value: nil)
     when Kind::BytesArray
-      Token.new(kind: token.kind, value: read_bytes_array)
+      read_bytes_array
     when Kind::StringArray
-      Token.new(kind: token.kind, value: read_string_array)
+      read_string_array
+    when Kind::Array
+      read_array(token)
     end
   end
 
   # Consumes the bytes array until it reaches a break
-  def read_bytes_array : CBOR::BytesArray
+  def read_bytes_array : Token
     bytes = BytesArray.new
+    chunks = Array(Int32).new
 
-    read_until(Kind::BytesArrayEnd, only: Kind::Bytes) do |chunk|
-      bytes << chunk.as(Bytes)
+    read_until(Kind::BytesArrayEnd, only: Kind::Bytes) do |c|
+      chunk = c.as(Bytes)
+      chunks << chunk.size
+      bytes << chunk
     end
 
-    bytes
+    Token.new(
+      kind: Kind::Bytes,
+      value: bytes.to_bytes,
+      chunks: chunks,
+    )
   end
 
   # Reads until break for chunks of strings
-  def read_string_array : CBOR::StringArray
-    strings = StringArray.new
+  def read_string_array : Token
+    value = ""
+    chunks = Array(Int32).new
 
-    read_until(Kind::StringArrayEnd, only: Kind::String) do |chunk|
-      strings << chunk.as(String)
+    read_until(Kind::StringArrayEnd, only: Kind::String) do |c|
+      chunk = c.as(String)
+      chunks << chunk.size
+      value += chunk
     end
 
-    strings
+    Token.new(
+      kind: Kind::String,
+      value: value,
+      chunks: chunks,
+    )
+  end
+
+  def read_array(token : Token) : Token
+    if token.size.nil?
+      token.size.not_nil!.times { token.value.as(Array(Type)) << read_value }
+    else
+      read_until(Kind::ArrayEnd) { |element| token.value.as(Array(Type)) << element }
+    end
+    token
   end
 
   private def next_token : Token?
@@ -151,7 +155,7 @@ class CBOR::Lexer
     when 0xff
       Token.new(kind: finish_token, value: nil)
     when 0x80..0x97
-      consume_array(current_byte - 0x80)
+      array_start(current_byte - 0x80)
     else
       raise ParseError.new("Unexpected first byte 0x#{current_byte.to_s(16)}")
     end
@@ -159,7 +163,7 @@ class CBOR::Lexer
 
   # Reads tokens until it meets the stop kind.
   # Optionally it can fail when the read token is not of the passed kind.
-  private def read_until(stop : Kind, only : Kind?, &block)
+  private def read_until(stop : Kind, only : Kind? = nil, &block)
     loop do
       token = next_token
       raise ParseError.new("Unexpected EOF") unless token
@@ -187,7 +191,9 @@ class CBOR::Lexer
     Token.new(kind: Kind::Int, value: value)
   end
 
-  private def consume_binary(size)
+  private def consume_binary(size : Int)
+    raise ParseError.new("Maximum size for binary array exeeded") if size > Int32::MAX
+
     bytes = read_bytes(size)
     Token.new(kind: Kind::Bytes, value: bytes)
   end
@@ -196,9 +202,10 @@ class CBOR::Lexer
     Token.new(kind: Kind::String, value: @io.read_string(size))
   end
 
-  private def consume_array(size)
-    arr = Array(CBOR::Type).new(size)
-    Token.new(kind: Kind::Array, value: arr)
+  private def array_start(size)
+    raise ParseError.new("Maximum size for array exeeded") if size > Int32::MAX
+    s = size.to_i32
+    Token.new(kind: Kind::Array, value: Array(Type).new(s), size: s)
   end
 
   private def open_token(kind : Kind) : Kind
diff --git a/src/cbor/token.cr b/src/cbor/token.cr
index 2ae74a4..ab48544 100644
--- a/src/cbor/token.cr
+++ b/src/cbor/token.cr
@@ -15,4 +15,10 @@ enum CBOR::Kind
   Map
 end
 
-record CBOR::Token, kind : Kind, value : Lexer::Type, size : Int64? = nil
+record CBOR::Token,
+  kind : Kind,
+  value : Type,
+  size : Int32? = nil,
+  # Used only for BytesArray and StringArray: it contains the size of each
+  # chunks composing the type
+  chunks : Array(Int32)? = nil
diff --git a/src/cbor/type/bytes_array.cr b/src/cbor/type/bytes_array.cr
index e13640a..0dc9d7c 100644
--- a/src/cbor/type/bytes_array.cr
+++ b/src/cbor/type/bytes_array.cr
@@ -12,12 +12,4 @@ class CBOR::BytesArray < Array(Bytes)
 
     bytes
   end
-
-  def to_diagnostic : String
-    "(_ #{map { |chunk| to_byte_diagnostic(chunk) }.join(", ")})"
-  end
-
-  private def to_byte_diagnostic(chunk : Bytes) : String
-    "h'#{chunk.hexstring}'"
-  end
 end
diff --git a/src/cbor/type/string_array.cr b/src/cbor/type/string_array.cr
deleted file mode 100644
index 10d09dd..0000000
--- a/src/cbor/type/string_array.cr
+++ /dev/null
@@ -1,13 +0,0 @@
-class CBOR::StringArray < Array(String)
-  def to_s : String
-    join
-  end
-
-  def to_diagnostic : String
-    "(_ #{map { |s| quote(s) }.join(", ")})"
-  end
-
-  private def quote(chunk : String) : String
-    %("#{chunk}")
-  end
-end