diff --git a/src/01_lexic/number.zig b/src/01_lexic/number.zig
index 98661b5..6f988e0 100644
--- a/src/01_lexic/number.zig
+++ b/src/01_lexic/number.zig
@@ -19,6 +19,7 @@ pub fn lex(
     cap: usize,
     start: usize,
     err: *errors.ErrorData,
+    alloc: std.mem.Allocator,
 ) LexError!?LexReturn {
     assert(start < cap);
     const first_char = input[start];
@@ -27,9 +28,9 @@ pub fn lex(
     if (first_char == '0' and cap > start + 1) {
         const second_char = input[start + 1];
         switch (second_char) {
-            'x', 'X' => return prefixed('x', input, cap, start, err),
-            'o', 'O' => return prefixed('o', input, cap, start, err),
-            'b', 'B' => return prefixed('b', input, cap, start, err),
+            'x', 'X' => return prefixed('x', input, cap, start, err, alloc),
+            'o', 'O' => return prefixed('o', input, cap, start, err, alloc),
+            'b', 'B' => return prefixed('b', input, cap, start, err, alloc),
             else => {
                 // Continue
             },
@@ -51,6 +52,7 @@ fn prefixed(
     cap: usize,
     start: usize,
     err: *errors.ErrorData,
+    alloc: std.mem.Allocator,
 ) !?LexReturn {
     const validator = switch (prefix) {
         'x' => utils.is_hex_digit,
@@ -64,7 +66,7 @@ fn prefixed(
     // There should be at least 1 valid digit
     if (end_position >= cap or !validator(input[end_position])) {
         // populate error information
-        err.init("Incomplete number", start, end_position);
+        try err.init("Incomplete number", start, end_position, alloc);
 
         // throw error
         return LexError.Incomplete;
@@ -254,7 +256,7 @@ test "should return null if not an integer" {
 
 test "should lex hex number" {
     const input = "0xa";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -268,7 +270,7 @@ test "should fail on integer with leading zero" {
     const input = "0322";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.LeadingZero);
         return;
     };
@@ -285,7 +287,7 @@ test "should fail on integer with leading zero" {
 
 test "should lex hex number 2" {
     const input = "  0Xff00AA  ";
-    const result = try lex(input, input.len, 2, undefined);
+    const result = try lex(input, input.len, 2, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -299,7 +301,7 @@ test "shouldnt parse incomplete hex number" {
     const input = "0xZZ";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.Incomplete);
         return;
     };
@@ -318,7 +320,7 @@ test "shouldnt parse incomplete hex number 2" {
     const input = "0x";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.Incomplete);
         return;
     };
@@ -335,7 +337,7 @@ test "shouldnt parse incomplete hex number 2" {
 
 test "should lex octal number" {
     const input = "0o755";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -347,7 +349,7 @@ test "should lex octal number" {
 
 test "should lex octal number 2" {
     const input = "  0o755  ";
-    const result = try lex(input, input.len, 2, undefined);
+    const result = try lex(input, input.len, 2, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -361,7 +363,7 @@ test "shouldnt parse incomplete octal number" {
     const input = "0o8";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.Incomplete);
         return;
     };
@@ -378,7 +380,7 @@ test "shouldnt parse incomplete octal number" {
 
 test "should lex binary number" {
     const input = "0b1011";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -392,7 +394,7 @@ test "shouldnt parse incomplete binary number" {
     const input = "0b2";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.Incomplete);
         return;
     };
@@ -409,7 +411,7 @@ test "shouldnt parse incomplete binary number" {
 
 test "should lex fp number 1" {
     const input = "1.2";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -423,7 +425,7 @@ test "should lex fp number 2" {
     const input = "0.1";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = try lex(input, input.len, 0, errdata);
+    const result = try lex(input, input.len, 0, errdata, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -435,7 +437,7 @@ test "should lex fp number 2" {
 
 test "should lex fp number 3" {
     const input = "123.456";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -449,7 +451,7 @@ test "should fail on incomplete fp number" {
     const input = "123.";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.IncompleteFloatingNumber);
         return;
     };
@@ -466,7 +468,7 @@ test "should fail on incomplete fp number" {
 
 test "should lex scientific number" {
     const input = "42e+3";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
@@ -480,7 +482,7 @@ test "should fail on incomplete scientific number" {
     const input = "123e";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.IncompleteScientificNumber);
         return;
     };
@@ -499,7 +501,7 @@ test "should fail on incomplete scientific number 2" {
     const input = "123e+";
     const errdata = try std.testing.allocator.create(errors.ErrorData);
     defer std.testing.allocator.destroy(errdata);
-    const result = lex(input, input.len, 0, errdata) catch |err| {
+    const result = lex(input, input.len, 0, errdata, std.testing.allocator) catch |err| {
         try std.testing.expect(err == token.LexError.IncompleteScientificNumber);
         return;
     };
@@ -516,7 +518,7 @@ test "should fail on incomplete scientific number 2" {
 
 test "should lex floating scientific number" {
     const input = "0.58e+3";
-    const result = try lex(input, input.len, 0, undefined);
+    const result = try lex(input, input.len, 0, undefined, std.testing.allocator);
 
     if (result) |tuple| {
         const r = tuple[0];
diff --git a/src/01_lexic/root.zig b/src/01_lexic/root.zig
index b5ab1d1..28d282b 100644
--- a/src/01_lexic/root.zig
+++ b/src/01_lexic/root.zig
@@ -43,7 +43,7 @@ pub fn tokenize(
 
         // attempt to lex a number
         var current_error: errors.ErrorData = undefined;
-        const number_lex = number.lex(input, input_len, actual_next_pos, &current_error) catch |e| switch (e) {
+        const number_lex = number.lex(input, input_len, actual_next_pos, &current_error, alloc) catch |e| switch (e) {
             // recoverable errors
             LexError.Incomplete => {
                 // add to list of errors
@@ -126,7 +126,7 @@ pub fn tokenize(
         else {
             // Create an error "nothing matched" and continue lexing
             // after the whitespace
-            current_error.init("Unrecognized character", actual_next_pos, actual_next_pos + 1);
+            try current_error.init("Unrecognized character", actual_next_pos, actual_next_pos + 1, alloc);
             try err_arrl.append(current_error);
             current_pos = ignore_until_whitespace(input, actual_next_pos);
             continue;
diff --git a/src/02_syntax/root.zig b/src/02_syntax/root.zig
index 979adb8..562fd2f 100644
--- a/src/02_syntax/root.zig
+++ b/src/02_syntax/root.zig
@@ -48,10 +48,11 @@ pub const Module = struct {
                 switch (e) {
                     error.Unmatched => {
                         // create the error value
-                        error_target.init(
+                        try error_target.init(
                             "No statement found",
                             current_pos,
                             current_pos + 1,
+                            allocator,
                         );
                         return error.Unmatched;
                     },
diff --git a/src/errors/root.zig b/src/errors/root.zig
index 9bf184c..56bf9a3 100644
--- a/src/errors/root.zig
+++ b/src/errors/root.zig
@@ -1,22 +1,33 @@
 const std = @import("std");
 
+pub const ErrorLabel = struct {
+    message: []const u8,
+    start: usize,
+    end: usize,
+};
+
 /// Holds information about errors generated during the compilation,
 /// and pretty prints them.
 pub const ErrorData = struct {
     reason: []const u8,
     start_position: usize,
     end_position: usize,
+    labels: std.ArrayList(ErrorLabel),
+    alloc: std.mem.Allocator,
 
     pub fn init(
         target: *@This(),
         reason: []const u8,
         start_position: usize,
         end_position: usize,
-    ) void {
+        alloc: std.mem.Allocator,
+    ) !void {
         target.* = .{
             .reason = reason,
             .start_position = start_position,
             .end_position = end_position,
+            .labels = std.ArrayList(ErrorLabel).init(alloc),
+            .alloc = alloc,
         };
     }
 
@@ -28,15 +39,11 @@ pub const ErrorData = struct {
         const error_message = try std.fmt.allocPrint(alloc,
             \\Error: {s}
             \\[{s}:{d}:{d}]
-            \\
-            \\ {d} | {s}
         , .{
             self.reason,
             filename,
             faulty_line.line_number,
             faulty_line.column_number,
-            faulty_line.line_number,
-            faulty_line.line,
         });
 
         return error_message;
@@ -47,9 +54,8 @@ pub const ErrorData = struct {
     // - Get previous, current and next line
     // - Display message
 
-    /// Does nothing at the moment
     pub fn deinit(self: *@This()) void {
-        _ = self;
+        self.labels.deinit(self.alloc);
     }
 };
 
@@ -150,6 +156,8 @@ test "should gen error message" {
         .reason = "Invalid identifier",
         .start_position = 6,
         .end_position = 9,
+        .labels = std.ArrayList(ErrorLabel).init(std.testing.allocator),
+        .alloc = std.testing.allocator,
     };
     const out = try err.get_error_str(source, "repl", std.testing.allocator);
     defer std.testing.allocator.free(out);
@@ -157,7 +165,5 @@ test "should gen error message" {
     try std.testing.expectEqualStrings(
         \\Error: Invalid identifier
         \\[repl:1:7]
-        \\
-        \\ 1 | print(ehh)
     , out);
 }