parse error infrastructure

compiler/reporting/src/error/parse.rs

@@ -0,0 +1,39 @@
+use roc_parse::parser::{Fail, FailReason};
+use std::path::PathBuf;
+
+use crate::report::{Report, RocDocAllocator};
+use ven_pretty::DocAllocator;
+
+pub fn parse_problem<'b>(
+    alloc: &'b RocDocAllocator<'b>,
+    filename: PathBuf,
+    problem: Fail,
+) -> Report<'b> {
+    use FailReason::*;
+
+    match problem.reason {
+        ArgumentsBeforeEquals => {
+            let doc = alloc.text("Unexpected tokens in front of the `=` symbol:");
+
+            Report {
+                filename,
+                doc,
+                title: "PARSE PROBLEM".to_string(),
+            }
+        }
+        other => {
+            //
+            //    Unexpected(char, Region),
+            //    OutdentedTooFar,
+            //    ConditionFailed,
+            //    LineTooLong(u32 /* which line was too long */),
+            //    TooManyLines,
+            //    Eof(Region),
+            //    InvalidPattern,
+            //    ReservedKeyword(Region),
+            //    ArgumentsBeforeEquals,
+            //}
+            todo!("unhandled parse error: {:?}", other)
+        }
+    }
+}