From 1fe96bdbf7456003874730b08c1b0b7cd58a8750 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Sat, 31 Dec 2022 00:28:49 +0100
Subject: [PATCH] Errors - Parser error structure

---
 src/errors.rs | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/errors.rs b/src/errors.rs
index 14e724b..aff25a3 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -1,3 +1,5 @@
+use crate::tokens::{Token, TokenType};
+
 /// Error handler. Can be used to print error messages; will also retain the
 /// current error status.
 #[derive(Default, Debug)]
@@ -21,3 +23,32 @@ impl ErrorHandler {
         println!("[line {line}] Error{pos}: {message}")
     }
 }
+
+/// An error that occurred while trying to parse the input once it has been
+/// scanned.
+#[derive(Debug, Clone)]
+pub struct ParserError {
+    line: usize,
+    pos: String,
+    message: String,
+}
+
+impl ParserError {
+    /// Initialize a parser error.
+    pub fn new(token: &Token, message: &str) -> Self {
+        Self {
+            line: token.line,
+            pos: if token.token_type == TokenType::EOF {
+                String::from(" at end of input")
+            } else {
+                format!("at '{}'", token.lexeme)
+            },
+            message: String::from(message),
+        }
+    }
+
+    /// Report the error to an error handler.
+    pub fn report(&self, err_hdl: &mut ErrorHandler) {
+        err_hdl.report(self.line, &self.pos, &self.message);
+    }
+}