From e04db0ac0c83dcc66e5b17f8c822cb9c8f60ce62 Mon Sep 17 00:00:00 2001
From: Krzosa Karol <git.exclaim518@passmail.net>
Date: Sun, 10 May 2026 14:38:03 +0200
Subject: [PATCH] Expand lexer support for expression tokens

---
 main.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 81 insertions(+), 14 deletions(-)

diff --git a/main.c b/main.c
index e34a729..fa852a0 100644
--- a/main.c
+++ b/main.c
@@ -128,11 +128,55 @@ Token lex_token(Lexer *lex) {
         case ';': t.kind = TOK_SEMICOLON; break;
         case '?': t.kind = TOK_QUESTION; break;
         case '#': t.kind = TOK_HASH; break;
-        case '+': t.kind = TOK_PLUS; break;
-        case '-': t.kind = TOK_MINUS; break;
-        case '*': t.kind = TOK_STAR; break;
-        case '/': t.kind = TOK_SLASH; break;
-        case '%': t.kind = TOK_PERCENT; break;
+        case '+': {
+            if (lex->at < lex->end && *lex->at == '+') {
+                lex_advance(lex);
+                t.kind = TOK_INC;
+            } else if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_PLUS_ASSIGN;
+            } else {
+                t.kind = TOK_PLUS;
+            }
+        } break;
+        case '-': {
+            if (lex->at < lex->end && *lex->at == '-') {
+                lex_advance(lex);
+                t.kind = TOK_DEC;
+            } else if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_MINUS_ASSIGN;
+            } else if (lex->at < lex->end && *lex->at == '>') {
+                lex_advance(lex);
+                t.kind = TOK_ARROW;
+            } else {
+                t.kind = TOK_MINUS;
+            }
+        } break;
+        case '*': {
+            if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_MUL_ASSIGN;
+            } else {
+                t.kind = TOK_STAR;
+            }
+        } break;
+        case '/': {
+            if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_DIV_ASSIGN;
+            } else {
+                t.kind = TOK_SLASH;
+            }
+        } break;
+        case '%': {
+            if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_MOD_ASSIGN;
+            } else {
+                t.kind = TOK_PERCENT;
+            }
+        } break;
         case '=': {
             if (lex->at < lex->end && *lex->at == '=') {
                 lex_advance(lex);
@@ -142,23 +186,33 @@ Token lex_token(Lexer *lex) {
             }
         } break;
         case '<': {
-            if (lex->at < lex->end && *lex->at == '=') {
+            if (lex->at < lex->end && *lex->at == '<') {
+                lex_advance(lex);
+                if (lex->at < lex->end && *lex->at == '=') {
+                    lex_advance(lex);
+                    t.kind = TOK_LSHIFT_ASSIGN;
+                } else {
+                    t.kind = TOK_LSHIFT;
+                }
+            } else if (lex->at < lex->end && *lex->at == '=') {
                 lex_advance(lex);
                 t.kind = TOK_LEQ;
-            } else if (lex->at < lex->end && *lex->at == '<') {
-                lex_advance(lex);
-                t.kind = TOK_LSHIFT;
             } else {
                 t.kind = TOK_LT;
             }
         } break;
         case '>': {
-            if (lex->at < lex->end && *lex->at == '=') {
+            if (lex->at < lex->end && *lex->at == '>') {
+                lex_advance(lex);
+                if (lex->at < lex->end && *lex->at == '=') {
+                    lex_advance(lex);
+                    t.kind = TOK_RSHIFT_ASSIGN;
+                } else {
+                    t.kind = TOK_RSHIFT;
+                }
+            } else if (lex->at < lex->end && *lex->at == '=') {
                 lex_advance(lex);
                 t.kind = TOK_GEQ;
-            } else if (lex->at < lex->end && *lex->at == '>') {
-                lex_advance(lex);
-                t.kind = TOK_RSHIFT;
             } else {
                 t.kind = TOK_GT;
             }
@@ -176,6 +230,9 @@ Token lex_token(Lexer *lex) {
             if (lex->at < lex->end && *lex->at == '&') {
                 lex_advance(lex);
                 t.kind = TOK_AND;
+            } else if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_AND_ASSIGN;
             } else {
                 t.kind = TOK_BITAND;
             }
@@ -184,11 +241,21 @@ Token lex_token(Lexer *lex) {
             if (lex->at < lex->end && *lex->at == '|') {
                 lex_advance(lex);
                 t.kind = TOK_OR;
+            } else if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_OR_ASSIGN;
             } else {
                 t.kind = TOK_BITOR;
             }
         } break;
-        case '^': t.kind = TOK_BITXOR; break;
+        case '^': {
+            if (lex->at < lex->end && *lex->at == '=') {
+                lex_advance(lex);
+                t.kind = TOK_XOR_ASSIGN;
+            } else {
+                t.kind = TOK_BITXOR;
+            }
+        } break;
         default: {
             // @todo: lexer perhaps should have a static buffer of size 1024, error message
             // should be put there and piped to the upper program. The token should be filled