From ff03ee922dbbdfd9c8e0d28aa898cbe8571eee70 Mon Sep 17 00:00:00 2001
From: Alejandro Mery <amery@jpi.io>
Date: Tue, 29 Aug 2023 02:41:48 +0000
Subject: [PATCH] lexer: introduce Error{}

Signed-off-by: Alejandro Mery <amery@jpi.io>
---
 lexer/error.go | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 lexer/error.go

diff --git a/lexer/error.go b/lexer/error.go
new file mode 100644
index 0000000..6ffd479
--- /dev/null
+++ b/lexer/error.go
@@ -0,0 +1,45 @@
+package lexer
+
+import (
+	"fmt"
+	"strings"
+)
+
+var (
+	_ error = (*Error)(nil)
+)
+
+// Error represents a generic parsing error
+type Error struct {
+	Filename string
+	Line     int
+	Column   int
+
+	Content string
+	Err     error
+}
+
+func (err Error) Error() string {
+	var s []string
+
+	switch {
+	case err.Line > 0 || err.Column > 0:
+		s = append(s, fmt.Sprintf("%s:%v:%v", err.Filename, err.Line, err.Column))
+	case err.Filename != "":
+		s = append(s, err.Filename)
+	}
+
+	if err.Err != nil {
+		s = append(s, err.Err.Error())
+	}
+
+	if err.Content != "" {
+		s = append(s, fmt.Sprintf("%q", err.Content))
+	}
+
+	return strings.Join(s, ": ")
+}
+
+func (err Error) Unwrap() error {
+	return err.Err
+}