diff --git a/src/lexer/lexer.c b/src/lexer/lexer.c
index bec5e24..16c8752 100644
--- a/src/lexer/lexer.c
+++ b/src/lexer/lexer.c
@@ -10,10 +10,12 @@
 #include "io_backend/io_backend.h"
 #include "utils/string_utils/string_utils.h"
 
+// ######## STATIC FUNCTIONS ##############
+
 /* @brief: sets the ctx->current_token to [tok].
  *        this function is called by token_peek().
  */
-static void update_ctx->current_token(struct token *tok, struct lexer_context *ctx)
+static void update_current_token(struct token *tok, struct lexer_context *ctx)
 {
     ctx->current_token = tok;
 }
@@ -22,7 +24,7 @@ static void update_ctx->current_token(struct token *tok, struct lexer_context *c
  *        Also sets ctx->current_token to NULL.
  *        this function is called by token_pop().
  */
-static void update_ctx->previous_token(struct token *tok, struct lexer_context *ctx)
+static void update_previous_token(struct token *tok, struct lexer_context *ctx)
 {
     free_token(&ctx->previous_token);
     ctx->previous_token = tok;
@@ -37,10 +39,10 @@ static void update_ctx->previous_token(struct token *tok, struct lexer_context *
 static void save_state(char *stream, ssize_t i, struct lexer_context *ctx)
 {
     ctx->remaining_chars -= i;
-    ctx->end_ctx->previous_token = stream + i;
+    ctx->end_previous_token = stream + i;
 
-    update_ctx->previous_token(ctx->current_token);
-    update_ctx->current_token(NULL);
+    update_previous_token(ctx->current_token);
+    update_current_token(NULL);
 }
 
 /* @return: true if a special character from the grammar was found,
@@ -176,6 +178,20 @@ static void set_token_word(struct token *tok, char *begin, ssize_t size)
     }
 }
 
+void destroy_lexer_context(struct lexer_context **ctx)
+{
+    if (ctx == NULL || *ctx == NULL)
+        return;
+    if (ctx->end_previous_token != NULL)
+        free(ctx->end_previous_token);
+    if (ctx->previous_token != NULL)
+        free(ctx->previous_token);
+    if (ctx->current_token != NULL)
+        free(ctx->current_token);
+    free(*ctx);
+    *ctx = NULL;
+}
+
 struct token *new_token(char *begin, ssize_t size)
 {
     struct token *tok = calloc(1, sizeof(struct token));
@@ -209,7 +225,7 @@ char *stream_init(struct lexer_context *ctx)
     }
     else
     {
-        stream = ctx->end_ctx->previous_token;
+        stream = ctx->end_previous_token;
     }
 
     char *trimed_stream = trim_blank_left(stream);
@@ -297,7 +313,7 @@ struct token *peek_token(struct lexer_context *ctx)
     }
 
     struct token *tok = new_token(stream, i);
-    update_ctx->current_token(tok);
+    update_current_token(tok);
     return tok;
 }
 
diff --git a/src/lexer/lexer.h b/src/lexer/lexer.h
index 95c5504..50003b2 100644
--- a/src/lexer/lexer.h
+++ b/src/lexer/lexer.h
@@ -5,13 +5,17 @@
 
 struct lexer_context
 {
-    char *end_last_token;
+    char *end_previous_token;
     ssize_t remaining_chars;
 
-    struct token *last_token;
+    struct token *previous_token;
     struct token *current_token;
 };
 
+/* @brief: frees all fields of ctx and sets ctx to NULL.
+ */
+void destroy_lexer_context(struct lexer_context **ctx);
+
 enum lexing_mode
 {
     LEXER_NORMAL,