From 1c4022cebcd3964d53630673981060d3d9eafbf9 Mon Sep 17 00:00:00 2001
From: Thomas Lindner <tom@dl6tom.de>
Date: Sat, 7 Jan 2023 16:07:24 +0100
Subject: [PATCH] add increment/decrement operators

---
 bootstrap/emit.cc      | 14 ++++++++++++++
 bootstrap/typecheck.cc | 15 +++++++++++++++
 bootstrap/xlang.g4     |  4 ++++
 test/fib.x             |  4 ++--
 test/sieve.x           |  4 ++--
 5 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/bootstrap/emit.cc b/bootstrap/emit.cc
index d4d37cb..5cfdbfb 100644
--- a/bootstrap/emit.cc
+++ b/bootstrap/emit.cc
@@ -190,6 +190,20 @@ std::any EmitVisitor::visitVariable(xlangParser::VariableContext *ctx) {
     last = "%_" + name;
     return {};
   }
+  if (ctx->Increment()) {
+    visitExpr(ctx->expr());
+    output << "  %_" << name << " = w add %_" << name << ", " << last
+           << std::endl;
+    last = "%_" + name;
+    return {};
+  }
+  if (ctx->Decrement()) {
+    visitExpr(ctx->expr());
+    output << "  %_" << name << " = w sub %_" << name << ", " << last
+           << std::endl;
+    last = "%_" + name;
+    return {};
+  }
   if (ctx->LeftParen()) {
     std::vector<std::string> args;
 
diff --git a/bootstrap/typecheck.cc b/bootstrap/typecheck.cc
index 8afb90a..9e75038 100644
--- a/bootstrap/typecheck.cc
+++ b/bootstrap/typecheck.cc
@@ -230,6 +230,21 @@ std::any TypeCheckVisitor::visitVariable(xlangParser::VariableContext *ctx) {
       return type;
     }
   }
+  if (auto expr = ctx->expr()) {
+    auto righttype = std::any_cast<Type>(visitExpr(expr));
+
+    if (auto lefttype = scope.get(name)) {
+      if (*lefttype != Type::Integer) {
+        errorlistener.typeMismatch(token, Type::Integer, *lefttype);
+      }
+    } else {
+      errorlistener.unknownVariable(token, name);
+    }
+    if (righttype != Type::Integer) {
+      errorlistener.typeMismatch(token, Type::Integer, righttype);
+    }
+    return Type::Integer;
+  }
   if (ctx->LeftParen()) {
     auto it = signatures.find(name);
 
diff --git a/bootstrap/xlang.g4 b/bootstrap/xlang.g4
index d1fa872..3b32a1b 100644
--- a/bootstrap/xlang.g4
+++ b/bootstrap/xlang.g4
@@ -43,6 +43,8 @@ factor  : Minus factor
 variable  : Identifier
           | Identifier Define value
           | Identifier Assign value
+          | Identifier Increment expr
+          | Identifier Decrement expr
           | Identifier LeftParen argumentList? RightParen
           ;
 argumentList  : value (Comma value)*;
@@ -87,6 +89,8 @@ BitNot  : '~';
 Mul : '*';
 Div : '/';
 Rem : '%';
+Increment : '=+';
+Decrement : '=-';
 Comma : ',';
 Semicolon : ';';
 
diff --git a/test/fib.x b/test/fib.x
index e097db3..c785953 100644
--- a/test/fib.x
+++ b/test/fib.x
@@ -3,7 +3,7 @@ main() : int {
   while i < 10 {
     print fib_rec(i);
     print fib_iter(i);
-    i = i + 1;
+    i =+ 1;
   }
 }
 
@@ -22,7 +22,7 @@ fib_iter(n : int) : int {
     t := x0 + x1;
     x0 = x1;
     x1 = t;
-    i = i + 1;
+    i =+ 1;
   }
   return x0;
 }
diff --git a/test/sieve.x b/test/sieve.x
index 751198b..f97ec62 100644
--- a/test/sieve.x
+++ b/test/sieve.x
@@ -9,11 +9,11 @@ main() : int {
         composite = true;
         break;
       }
-      j = j + 2;
+      j =+ 2;
     }
     if not composite {
       print i;
     }
-    i = i + 2;
+    i =+ 2;
   }
 }