From 4d56a673346e5e5bde0de0744a6c794537c27172 Mon Sep 17 00:00:00 2001
From: Nikolai Ponomarev <wowasterdev@gmail.com>
Date: Sat, 26 Oct 2024 11:50:55 +0300
Subject: [PATCH] Make error messages more clear

---
 lamagraph-compiler/lamagraph-compiler.cabal            | 3 +++
 lamagraph-compiler/package.yaml                        | 1 +
 lamagraph-compiler/src/Lamagraph/Compiler/PrettyLml.hs | 8 ++++++--
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/lamagraph-compiler/lamagraph-compiler.cabal b/lamagraph-compiler/lamagraph-compiler.cabal
index ce8fb45..79553af 100644
--- a/lamagraph-compiler/lamagraph-compiler.cabal
+++ b/lamagraph-compiler/lamagraph-compiler.cabal
@@ -61,6 +61,7 @@ library
     , lens
     , prettyprinter
     , relude
+    , string-interpolate
   default-language: GHC2021
 
 executable lamagraph-compiler-exe
@@ -84,6 +85,7 @@ executable lamagraph-compiler-exe
     , lens
     , prettyprinter
     , relude
+    , string-interpolate
   default-language: GHC2021
 
 test-suite lamagraph-compiler-test
@@ -115,6 +117,7 @@ test-suite lamagraph-compiler-test
     , lens
     , prettyprinter
     , relude
+    , string-interpolate
     , tasty
     , tasty-golden
     , tasty-hedgehog
diff --git a/lamagraph-compiler/package.yaml b/lamagraph-compiler/package.yaml
index 16486f8..bfda82f 100644
--- a/lamagraph-compiler/package.yaml
+++ b/lamagraph-compiler/package.yaml
@@ -26,6 +26,7 @@ dependencies:
   - extra
   - lens
   - prettyprinter
+  - string-interpolate
 
 language: GHC2021
 
diff --git a/lamagraph-compiler/src/Lamagraph/Compiler/PrettyLml.hs b/lamagraph-compiler/src/Lamagraph/Compiler/PrettyLml.hs
index 74aabda..9e27ea0 100644
--- a/lamagraph-compiler/src/Lamagraph/Compiler/PrettyLml.hs
+++ b/lamagraph-compiler/src/Lamagraph/Compiler/PrettyLml.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE QuasiQuotes #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
 
 {- | Orphan instances for pretty-printing LamagraphML
@@ -8,6 +9,7 @@ module Lamagraph.Compiler.PrettyLml () where
 
 import Relude
 
+import Data.String.Interpolate (i)
 import Data.Text qualified as T
 import Prettyprinter
 
@@ -17,7 +19,9 @@ import Lamagraph.Compiler.Syntax
 
 prettyADTVar :: LLmlType (LmlcPass pass) -> Doc ann
 prettyADTVar (L _ (LmlTyVar _ varName)) = "'" <> pretty varName
-prettyADTVar _ = error "Internal pretty-printer error: cannot have complex types in type parameters"
+prettyADTVar t =
+  error
+    [i|Internal pretty-printer error: expected list of type variables in AST as a type parameters, but got #{pretty t}|]
 
 prettyADTVars :: [LLmlType (LmlcPass pass)] -> Doc ann
 prettyADTVars [] = emptyDoc
@@ -31,7 +35,7 @@ prettyChar '\'' = "\\\'"
 prettyChar '\n' = "\\\n"
 prettyChar c
   | c `elem` ['\32' .. '\127'] = pretty c
-  | otherwise = error "Internal pretty-printer error: trying to print unsupported character"
+  | otherwise = error [i|Internal pretty-printer error: trying to print unsupported in LML character "#{c}"|]
 
 prettyString :: Text -> Doc ann
 prettyString str = mconcat $ map prettyChar (toString str)