Print a horizontal rule after the last error

compiler/build/src/program.rs

@@ -42,10 +42,12 @@ pub fn gen_from_mono_module(
     use std::time::SystemTime;
 
     use roc_reporting::report::{
-        can_problem, mono_problem, type_problem, RocDocAllocator, DEFAULT_PALETTE,
+        can_problem, mono_problem, type_problem, Report, RocDocAllocator, DEFAULT_PALETTE,
     };
 
     let code_gen_start = SystemTime::now();
+    let total_problems = loaded.total_problems();
+    let palette = DEFAULT_PALETTE;
 
     for (home, (module_path, src)) in loaded.sources {
         let mut src_lines: Vec<&str> = Vec::new();
@@ -56,7 +58,6 @@ pub fn gen_from_mono_module(
         } else {
             src_lines.extend(src.split('\n'));
         }
-        let palette = DEFAULT_PALETTE;
 
         // Report parsing and canonicalization problems
         let alloc = RocDocAllocator::new(&src_lines, home, &loaded.interns);
@@ -92,6 +93,16 @@ pub fn gen_from_mono_module(
         }
     }
 
+    // If we printed any problems, print a horizontal rule at the end,
+    // and then clear any ANSI escape codes (e.g. colors) we've used.
+    //
+    // The horizontal rule is nice when running the program right after
+    // compiling it, as it lets you clearly see where the compiler
+    // errors/warnings end and the program output begins.
+    if total_problems > 0 {
+        println!("{}\u{001B}[0m\n", Report::horizontal_rule(&palette));
+    }
+
     // Generate the binary
     let ptr_bytes = target.pointer_width().unwrap().bytes() as u32;
     let context = Context::create();

compiler/load/src/file.rs

@@ -721,6 +721,12 @@ pub struct MonomorphizedModule<'a> {
     pub timings: MutMap<ModuleId, ModuleTiming>,
 }
 
+impl<'a> MonomorphizedModule<'a> {
+    pub fn total_problems(&self) -> usize {
+        self.can_problems.len() + self.type_problems.len() + self.mono_problems.len()
+    }
+}
+
 #[derive(Debug, Default)]
 pub struct VariablySizedLayouts<'a> {
     rigids: MutMap<Lowercase, Layout<'a>>,

compiler/reporting/src/report.rs

@@ -119,6 +119,10 @@ impl<'b> Report<'b> {
             ])
         }
     }
+
+    pub fn horizontal_rule(palette: &'b Palette) -> String {
+        format!("{}{}", palette.header, "─".repeat(80))
+    }
 }
 
 pub struct Palette<'a> {