nightshade

commit 1dfe3c590a36aa11a01e912656ce0069374384a9
parent 9f012042269d72e38f9fd0c6e5962c54af2933a0
Author: citbl <citbl@citbl.org>
Date:   Fri,  5 Jun 2026 17:22:38 +1000

parser wip

Diffstat:
M
src/parser.adb
 | 
46
++++++++++++++++++++++++++++++++++++++--------

1 file changed, 38 insertions(+), 8 deletions(-)
diff --git a/src/parser.adb b/src/parser.adb
@@ -3,10 +3,16 @@ with Lexer; use Lexer;
 package body Parser is
 
    function Init
-     (File_Name : File_Name_Ref; Source : Source_Ref; Tokens : Token_Vector.Vector) return Parser
+     (File_Name : File_Name_Ref;
+      Source    : Source_Ref;
+      Tokens    : Token_Vector.Vector) return Parser
    is
       P : Parser :=
-        (Source => Source, File_Name => File_Name, Tokens => Tokens, Pos => 1, AST => null);
+        (Source    => Source,
+         File_Name => File_Name,
+         Tokens    => Tokens,
+         Pos       => 1,
+         AST       => null);
    begin
       return P;
    end Init;
@@ -17,9 +23,13 @@ package body Parser is
    begin
       if P.Pos < P.Tokens.Last_Index then
          return P.Tokens (P.Pos);
-      else
-         return Token'(Kind => EOF, Lexeme => To_Unbounded_String (""), Line => 1, Col => 1);
       end if;
+      return
+        Token'
+          (Kind   => EOF,
+           Lexeme => To_Unbounded_String (""),
+           Line   => 1,
+           Col    => 1);
    end Peek;
 
    -- peek2
@@ -28,11 +38,32 @@ package body Parser is
    begin
       if P.Pos + 1 < P.Tokens.Last_Index then
          return P.Tokens (P.Pos + 1);
-      else
-         return Token'(Kind => EOF, Lexeme => To_Unbounded_String (""), Line => 1, Col => 1);
       end if;
+      return
+        Token'
+          (Kind   => EOF,
+           Lexeme => To_Unbounded_String (""),
+           Line   => 1,
+           Col    => 1);
    end Peek2;
 
+   -- match
+
+   function Match (P : in Parser; Kind : Token_Kind) return Token is
+      T : Token;
+   begin
+      if P.Pos < P.Tokens.Last_Index then
+         T := P.Tokens (P.Pos);
+         if T.Kind = Kind then
+            return T;
+         else
+            raise Program_Error
+              with "expected different token: " & Token_Kind'Image (Kind);
+         end if;
+      end if;
+      raise Program_Error with "Match: Token out of bounds";
+   end Match;
+
    -- consume
 
    function Consume (P : in out Parser) return Token is
@@ -42,9 +73,8 @@ package body Parser is
          T := P.Tokens (P.Pos);
          P.Pos := P.Pos + 1;
          return T;
-      else
-         return Token'(Kind => EOF, Lexeme => To_Unbounded_String (""), Line => 1, Col => 1);
       end if;
+      raise Program_Error with "Consume: Token out of bounds";
    end Consume;
 
    -- parse program