diff --git a/lexer/lexer.go b/lexer/lexer.go
new file mode 100644
index 0000000..bdbc429
--- /dev/null
+++ b/lexer/lexer.go
@@ -0,0 +1,21 @@
+package lexer
+
+import (
+        "github.com/sashakoshka/arf/file"
+)
+
+// LexingOperation holds information about an ongoing lexing operataion.
+type LexingOperation struct {
+	file *file.File
+}
+
+// Tokenize converts a file into a slice of tokens (lexemes)
+func Tokenize (file *file.File) (tokens []Token) {
+	lexer := LexingOperation { }
+	return lexer.tokenize(file)
+}
+
+// tokenize converts a file into a slice of tokens (lexemes)
+func (lexer *LexingOperation) tokenize (file *file.File) (tokens []Token) {
+	return
+}