From 7faccc9923a5e2a128b44ab59511a1745eb98d83 Mon Sep 17 00:00:00 2001
From: Vasilii Rogin <vasya@rogin.ru>
Date: Sun, 14 May 2023 21:26:32 +0300
Subject: [PATCH] Add string subscript

---
 src/sfall_opcodes.cc | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/sfall_opcodes.cc b/src/sfall_opcodes.cc
index c9a76bd..97d8d6e 100644
--- a/src/sfall_opcodes.cc
+++ b/src/sfall_opcodes.cc
@@ -568,16 +568,27 @@ static void opScanArray(Program* program)
 // get_array
 static void opGetArray(Program* program)
 {
-    // TODO: If type is string then do substr instead of array operation
-
     auto key = programStackPopValue(program);
 
     auto arrayId = programStackPopValue(program);
     if (arrayId.isInt()) {
         auto value = GetArray(arrayId.integerValue, key);
         programStackPushValue(program, value);
-    } else if (arrayId.isString()) {
-        throw std::invalid_argument("String subscript is not implemented yet!");
+    } else if (arrayId.isString() && key.isInt()) {
+
+        auto& strVal = arrayId;
+        auto pos = key.asInt();
+        auto str = programGetString(program, strVal.opcode, strVal.integerValue);
+
+        //  TODO: Is this works?
+
+        char buf[2] = { 0 };
+        if (pos < strlen(str)) {
+            buf[0] = str[pos];
+            programPushString(program, buf);
+        } else {
+            programPushString(program, buf);
+        }
     }
 }