Init

.gitignore

@@ -0,0 +1,2 @@
+/target
+Cargo.lock

Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "lalrpop_codespan"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1.0.52"
+codespan-reporting = "0.11.1"
+lalrpop-util = { version = "0.19.6", features = ["lexer"] }

src/lib.rs

@@ -0,0 +1,50 @@
+use anyhow::bail;
+use codespan_reporting::{
+    diagnostic::{Diagnostic, Label},
+    files::SimpleFiles,
+    term::{
+        emit,
+        termcolor::{ColorChoice, StandardStream},
+    },
+};
+use lalrpop_util::{lexer::Token, ParseError};
+
+pub fn report_error<T>(
+    tree: Result<T, ParseError<usize, Token, &str>>,
+    file_name: &str,
+    file_contents: &str,
+) -> anyhow::Result<T> {
+    match tree {
+        Ok(x) => Ok(x),
+        Err(e) => {
+            let mut err_files = SimpleFiles::new();
+            let err_writer = StandardStream::stderr(ColorChoice::Auto);
+            let err_config = codespan_reporting::term::Config::default();
+
+            let main_file_id = err_files.add(file_name, file_contents);
+            let emit_err = |d| emit(&mut err_writer.lock(), &err_config, &err_files, d);
+
+            let err = match e {
+                ParseError::InvalidToken { location } => Diagnostic::error()
+                    .with_message("Invalid token")
+                    .with_labels(vec![Label::primary(main_file_id, location..location + 1)]),
+                ParseError::UnrecognizedEOF { location, expected } => Diagnostic::error()
+                    .with_message("Unexpected end of file")
+                    .with_labels(vec![Label::primary(main_file_id, location..location + 1)])
+                    .with_notes(expected.iter().map(|e| format!("Expected {}", e)).collect()),
+                ParseError::UnrecognizedToken { token, expected } => Diagnostic::error()
+                    .with_message("Unrecognized token")
+                    .with_labels(vec![Label::primary(main_file_id, token.0..token.2)])
+                    .with_notes(expected.iter().map(|e| format!("Expected {}", e)).collect()),
+                ParseError::ExtraToken { token } => Diagnostic::error()
+                    .with_message("Extra token")
+                    .with_labels(vec![Label::primary(main_file_id, token.0..token.2)]),
+                ParseError::User { error } => bail!("User parse error: {}", error),
+            };
+
+            emit_err(&err)?;
+
+            bail!("Parse error");
+        }
+    }
+}