From ae311809ee98d7797b7d3f57d273a46399560869 Mon Sep 17 00:00:00 2001
From: Bernard Teo <btzy1996@hotmail.com>
Date: Wed, 23 Aug 2017 15:41:25 +0800
Subject: [PATCH] allow breakpoint on first character

---
 jelly-bf-interpreter.js | 9 ++++++++-
 jelly-bf-worker.max.js  | 7 +++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/jelly-bf-interpreter.js b/jelly-bf-interpreter.js
index d2c25c1..e2c0bc9 100644
--- a/jelly-bf-interpreter.js
+++ b/jelly-bf-interpreter.js
@@ -30,7 +30,11 @@ JellyBFInterpreter=function(codeString,get_input,put_output,breakpointuint8array
     }
     if(loop_stack.length!==0)throw JellyBFInterpreter.CompileError.LOOPS_IMBALANCED;
     this.next_instruction_index[last_instruction_index]=Number.MAX_SAFE_INTEGER;
-    this.instruction_ptr=this.entry_point;
+    // allow breakpointing first character:
+    var pseudo_entry_index=this.code.length;
+    this.code+="`";
+    this.next_instruction_index[pseudo_entry_index]=this.entry_point;
+    this.instruction_ptr=pseudo_entry_index;
 };
 JellyBFInterpreter.CompileError={
     LOOPS_IMBALANCED:1
@@ -80,6 +84,9 @@ JellyBFInterpreter.prototype.run=function(){
         else if(this.code[this.instruction_ptr]==="."){
             this.put_output(Atomics.load(this.memory,this.memory_ptr));
         }
+        else if(this.code[this.instruction_ptr]==="`"){
+            // don't do anything
+        }
         else{
             throw "Internal error!";
         }
diff --git a/jelly-bf-worker.max.js b/jelly-bf-worker.max.js
index edd9793..67b1166 100644
--- a/jelly-bf-worker.max.js
+++ b/jelly-bf-worker.max.js
@@ -1570,7 +1570,10 @@ JellyBFInterpreter = function(codeString, get_input, put_output, breakpointuint8
     }
     if (loop_stack.length !== 0) throw JellyBFInterpreter.CompileError.LOOPS_IMBALANCED;
     this.next_instruction_index[last_instruction_index] = Number.MAX_SAFE_INTEGER;
-    this.instruction_ptr = this.entry_point;
+    var pseudo_entry_index = this.code.length;
+    this.code += "`";
+    this.next_instruction_index[pseudo_entry_index] = this.entry_point;
+    this.instruction_ptr = pseudo_entry_index;
 };
 
 JellyBFInterpreter.CompileError = {
@@ -1612,7 +1615,7 @@ JellyBFInterpreter.prototype.run = function() {
             Atomics.store(this.memory, this.memory_ptr, this.get_input());
         } else if (this.code[this.instruction_ptr] === ".") {
             this.put_output(Atomics.load(this.memory, this.memory_ptr));
-        } else {
+        } else if (this.code[this.instruction_ptr] === "`") {} else {
             throw "Internal error!";
         }
         this.instruction_ptr = this.next_instruction_index[this.instruction_ptr];