From 13efaa5e170dfb38a8f4f2f8a23ebe804d49ea4a Mon Sep 17 00:00:00 2001
From: Nocturn9x <hackhab@gmail.com>
Date: Fri, 15 Oct 2021 15:19:23 +0200
Subject: [PATCH] Added constant folding for string multiplication

---
 src/backend/optimizer.nim | 21 +++++++++++++++++++++
 src/main.nim              |  1 +
 2 files changed, 22 insertions(+)

diff --git a/src/backend/optimizer.nim b/src/backend/optimizer.nim
index cd4fe0d..f09c756 100644
--- a/src/backend/optimizer.nim
+++ b/src/backend/optimizer.nim
@@ -17,6 +17,7 @@ import meta/token
 
 import parseutils
 import strformat
+import strutils
 import math
 
 
@@ -240,6 +241,26 @@ proc optimizeBinary(self: Optimizer, node: BinaryExpr): ASTNode =
                 result = StrExpr(kind: strExpr, literal: Token(kind: String, lexeme: "'" & a.literal.lexeme[1..<(^1)] & b.literal.lexeme[1..<(^1)] & "'", pos: (start: -1, stop: -1)))
             else:
                 result = node
+    elif a.kind == strExpr and self.optimizeNode(b).kind == intExpr and not (self.warnings.len() > 0 and self.warnings[^1].kind == valueOverflow and self.warnings[^1].node == b):
+        var a = StrExpr(a)
+        var b = IntExpr(b)
+        var bb: int
+        discard parseInt(b.literal.lexeme, bb)
+        case node.operator.kind:
+            of Asterisk:
+                result = StrExpr(kind: strExpr, literal: Token(kind: String, lexeme: "'" & a.literal.lexeme[1..<(^1)].repeat(bb) & "'"))
+            else:
+                result = node
+    elif b.kind == strExpr and self.optimizeNode(a).kind == intExpr and not (self.warnings.len() > 0 and self.warnings[^1].kind == valueOverflow and self.warnings[^1].node == a):
+        var b = StrExpr(b)
+        var a = IntExpr(a)
+        var aa: int
+        discard parseInt(a.literal.lexeme, aa)
+        case node.operator.kind:
+            of Asterisk:
+                result = StrExpr(kind: strExpr, literal: Token(kind: String, lexeme: "'" & b.literal.lexeme[1..<(^1)].repeat(aa) & "'"))
+            else:
+                result = node
     else:
         # There's no constant folding we can do!
         result = node
diff --git a/src/main.nim b/src/main.nim
index f45fca0..1b42b15 100644
--- a/src/main.nim
+++ b/src/main.nim
@@ -24,6 +24,7 @@ var tokens: seq[Token]
 var tree: seq[ASTNode]
 var optimized: tuple[tree: seq[ASTNode], warnings: seq[Warning]]
 
+
 echo "NimVM REPL\n"
 while true:
     try: