Simplified file structure

src/errors/Error.go

@@ -0,0 +1,67 @@
+package errors
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"git.akyoto.dev/cli/q/src/fs"
+	"git.akyoto.dev/cli/q/src/token"
+)
+
+// Error is a compiler error at a given line and column.
+type Error struct {
+	Err      error
+	File     *fs.File
+	Stack    string
+	Position token.Position
+}
+
+// New generates an error message at the current token position.
+// The error message is clickable in popular editors and leads you
+// directly to the faulty file at the given line and position.
+func New(err error, file *fs.File, position token.Position) *Error {
+	return &Error{
+		Err:      err,
+		File:     file,
+		Position: position,
+		Stack:    Stack(),
+	}
+}
+
+// Error generates the string representation.
+func (e *Error) Error() string {
+	path := e.File.Path
+	cwd, err := os.Getwd()
+
+	if err == nil {
+		relativePath, err := filepath.Rel(cwd, e.File.Path)
+
+		if err == nil {
+			path = relativePath
+		}
+	}
+
+	line := 1
+	column := 1
+	lineStart := -1
+
+	for _, t := range e.File.Tokens {
+		if t.Position >= e.Position {
+			column = int(e.Position) - lineStart
+			break
+		}
+
+		if t.Kind == token.NewLine {
+			lineStart = int(t.Position)
+			line++
+		}
+	}
+
+	return fmt.Sprintf("%s:%d:%d: %s\n\n%s", path, line, column, e.Err, e.Stack)
+}
+
+// Unwrap returns the wrapped error.
+func (e *Error) Unwrap() error {
+	return e.Err
+}