better error outputs

1 files changed, 46 insertions, 11 deletions

diff --git a/src/fexpr/mod.rs b/src/fexpr/mod.rs
index aafdea7..5754d94 100644
--- a/src/fexpr/mod.rs
+++ b/src/fexpr/mod.rs
@@ -4,28 +4,63 @@
 //! type and convert it to a [`Filter`][super::filters::Filter].
 // Make it available in the grammar mod.
 use super::{filters, FightOutcome, SearchField, Weekday};
-use lalrpop_util::{lalrpop_mod, lexer::Token, ParseError};
 
+use std::{error, fmt};
+
+use lalrpop_util::{lalrpop_mod, lexer::Token, ParseError};
 use thiserror::Error;
 
-lalrpop_mod!(pub grammar, "/fexpr/grammar.rs");
+lalrpop_mod!(#[allow(clippy::all)] pub grammar, "/fexpr/grammar.rs");
+
+#[derive(Debug)]
+pub struct FError {
+    location: usize,
+    data: String,
+    kind: FErrorKind,
+}
+
+impl fmt::Display for FError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} (at {})", self.kind, self.location)
+    }
+}
+
+impl error::Error for FError {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        Some(&self.kind)
+    }
+}
 
 #[derive(Debug, Error)]
-pub enum FError {
+pub enum FErrorKind {
     #[error("invalid regular expression: {0}")]
-    InvalidRegex(String),
-    #[error("invalid fight outcome: {0}")]
-    InvalidFightOutcome(String),
-    #[error("invalid weekday: {0}")]
-    InvalidWeekday(String),
+    InvalidRegex(#[from] regex::Error),
+    #[error("invalid fight outcome")]
+    InvalidFightOutcome,
+    #[error("invalid weekday")]
+    InvalidWeekday,
     #[error("invalid timestamp: {0}")]
-    InvalidTimestamp(String),
-    #[error("invalid boss name: {0}")]
-    InvalidBoss(String),
+    InvalidTimestamp(#[from] chrono::format::ParseError),
+    #[error("invalid boss name")]
+    InvalidBoss,
 }
 
+/// Shortcut to create a new parser and parse the given input.
 pub fn parse_logfilter(
     input: &str,
 ) -> Result<Box<dyn filters::log::LogFilter>, ParseError<usize, Token, FError>> {
     grammar::LogFilterParser::new().parse(input)
 }
+
+/// Extract the location from the given error.
+pub fn location<T>(err: &ParseError<usize, T, FError>) -> usize {
+    match *err {
+        ParseError::InvalidToken { location } => location,
+        ParseError::UnrecognizedEOF { location, .. } => location,
+        ParseError::UnrecognizedToken {
+            token: (l, _, _), ..
+        } => l,
+        ParseError::ExtraToken { token: (l, _, _) } => l,
+        ParseError::User { ref error } => error.location,
+    }
+}