feat: semantic error messages make use of msg strings passed from typeChecker

src/main/wacc/Error.scala

@@ -6,7 +6,6 @@ import wacc.types._
 enum Error {
   case DuplicateDeclaration(ident: ast.Ident)
   case UndefinedIdentifier(ident: ast.Ident, identType: renamer.IdentType)
-
   case FunctionParamsMismatch(pos: Position, expected: Int, got: Int)
   case SemanticError(pos: Position, msg: String)
   case TypeMismatch(pos: Position, expected: SemType, got: SemType, msg: String)
@@ -18,25 +17,23 @@ def printError(error: Error)(using errorContent: String): Unit = {
   error match {
     case Error.DuplicateDeclaration(ident) =>
       printPosition(ident.getPosition)
-      println(
+      println(s"Duplicate declaration of identifier ${ident.v}")
-        s"Duplicate declaration of identifier ${ident.v}"
-      )
       highlight(ident.getPosition, ident.v.length)
     case Error.UndefinedIdentifier(ident, identType) =>
       printPosition(ident.getPosition)
-      println(
+      println(s"Undefined ${identType.toString.toLowerCase()} ${ident.v}")
-        s"Undefined ${identType.toString.toLowerCase()} ${ident.v}"
-      )
       highlight(ident.getPosition, ident.v.length)
     case Error.FunctionParamsMismatch(pos, expected, got) =>
       printPosition(pos)
       println(s"Function expects $expected parameters, got $got")
       highlight(pos, 1)
     case Error.TypeMismatch(pos, expected, got, msg) =>
-      println(s"Type mismatch: expected $expected, got $got")
+      printPosition(pos)
+      println(msg)
+      highlight(pos, 1)
     case Error.SemanticError(pos, msg) =>
       printPosition(pos)
-      println(s"$msg at line: ${pos.line} column: ${pos.column}")
+      println(msg)
       highlight(pos, 1)
     case wacc.Error.InternalError(pos, msg) =>
       printPosition(pos)

src/main/wacc/parser.scala

@@ -12,8 +12,6 @@ import cats.data.NonEmptyList
 import parsley.errors.DefaultErrorBuilder
 import parsley.errors.ErrorBuilder
 import parsley.errors.tokenextractors.LexToken
-import parsley.errors.patterns.VerifiedErrors
-import parsley.character.char
 
 object parser {
   import lexer.implicits.implicitSymbol
@@ -50,9 +48,6 @@ object parser {
     case Expr
     case Pair
 
-  val _parensCheck =
-    char('(').verifiedExplain("use keyword 'call' to call functions")
-
   implicit val builder: ErrorBuilder[String] = new DefaultErrorBuilder with LexToken {
     def tokens = errTokens
   }
@@ -71,8 +66,8 @@ object parser {
         GreaterEq from ">="
       ) +:
       SOps(InfixL)(
-        ((Add from "+").label("binary operator") | _parensCheck),
+        (Add from "+").label("binary operator"),
-        ((Sub from "-").label("binary operator") | _parensCheck)
+        (Sub from "-").label("binary operator")
       ) +:
       SOps(InfixL)(Mul from "*", Div from "/", Mod from "%") +:
       SOps(Prefix)(
@@ -115,16 +110,13 @@ object parser {
   private lazy val `<pair-elem-type>` =
     (`<base-type>` <**> (`<array-type>` </> identity)) |
       ((UntypedPairType from `<pair-type>`) <**>
-        ((`<pair-elems-type>` <**> `<array-type>`.explain(
+        ((`<pair-elems-type>` <**> `<array-type>`)
-          "non-erased pair types cannot be nested"
+          .map(arr => (_: UntypedPairType) => arr) </> identity))
-        )).map(arr => (_: UntypedPairType) => arr) </> identity))
 
   // Statements
   private lazy val `<program>` = Program(
     "begin" ~> many(
-      atomic(
+      atomic(`<type>`.label("function declaration") <~> `<ident>` <~ "(") <**> `<partial-func-decl>`
-        (`<type>`.label("function declaration") <~> `<ident>` <~ "(")
-      ) <**> `<partial-func-decl>`
     ).label("function declaration"),
     (atomic(`<ident>` <~ "(") ~> fail("function is missing return type") | `<stmt>`.label(
       "main program body"
@@ -132,9 +124,9 @@ object parser {
   )
   private lazy val `<partial-func-decl>` =
     FuncDecl(
-      sepBy(`<param>`, ",") <~ ")".label("parenthesis") <~ "is",
+      sepBy(`<param>`, ",") <~ ")" <~ "is",
       `<stmt>`.guardAgainst {
-        case stmts if !stmts.isReturning => Seq("all functions must end in a returning statement")
+        case stmts if !stmts.isReturning => Seq("All functions must end in a returning statement")
       } <~ "end"
     )
   private lazy val `<param>` = Param(`<type>`, `<ident>`)
@@ -159,11 +151,8 @@ object parser {
       )
       | While("while" ~> `<expr>`.labelWithType(LabelType.Expr) <~ "do", `<stmt>` <~ "done")
       | Block("begin" ~> `<stmt>` <~ "end")
-      | VarDecl(
+      | VarDecl(`<type>`, `<ident>` <~ "=", `<rvalue>`.label("valid initial value for variable"))
-        `<type>`,
+      // TODO: Can we inline the name of the variable in the message
-        `<ident>` <~ "=".explain("functions must be defined on top of the main block"),
-        `<rvalue>`.label("valid initial value for variable")
-      )
       | Assign(`<lvalue>` <~ "=", `<rvalue>`)
   private lazy val `<lvalue>`: Parsley[LValue] =
     `<pair-elem>` | `<ident-or-array-elem>`