diff --git a/benchmarks/fib.nds b/benchmarks/fib.nds
index c48a94c..573dcc5 100644
--- a/benchmarks/fib.nds
+++ b/benchmarks/fib.nds
@@ -1,6 +1,6 @@
 var fib = funct(n)
-  if (n < 2) :result = 1.5
+  if (n < 2) :result = 1
   else :result = fib(n-1) + fib(n-2)
 ;
 
-print fib(37.2);
\ No newline at end of file
+print fib(37);
\ No newline at end of file
diff --git a/examples/bf.nds b/examples/bf.nds
index 30b5680..ddca6f8 100644
--- a/examples/bf.nds
+++ b/examples/bf.nds
@@ -1,11 +1,6 @@
-{
+var main = funct() {
   // source
-  var src = ">++++++++++>+>+[
-    [+++++[>++++++++<-]>.<++++++[>--------<-]+<<<]>.>>[
-        [-]<[>+<-]>>[<<+>+>-]<[>+<-[>+<-[>+<-[>+<-[>+<-[>+<-
-            [>+<-[>+<-[>+<-[>[-]>+>+<<<-[>+<-]]]]]]]]]]]+>>>
-    ]<<<
-]";
+  var src = ">++++++++++[<++++++++++>-]<->>>>>+++[>+++>+++<<-]<<<<+<[>[>+>+<<-]>>[-<<+>>]++++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[[-]>>>>>>[[-]<++++++++++<->>]<-[>+>+<<-]>[<+>-]+>[[-]<->]<<<<<<<<<->>]<[>+>+<<-]>>[-<<+>>]+>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<<[>>+>+<<<-]>>>[-<<<+>>>]++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[>+<[-]]<[>>+<<[-]]>>[<<+>>[-]]<<<[>>+>+<<<-]>>>[-<<<+>>>]++++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[>+<[-]]<[>>+<<[-]]>>[<<+>>[-]]<<[[-]>>>++++++++[>>++++++<<-]>[<++++++++[>++++++<-]>.<++++++++[>------<-]>[<<+>>-]]>.<<++++++++[>>------<<-]<[->>+<<]<++++++++[<++++>-]<.>+++++++[>+++++++++<-]>+++.<+++++[>+++++++++<-]>.+++++..--------.-------.++++++++++++++>>[>>>+>+<<<<-]>>>>[-<<<<+>>>>]>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<<<[>>>+>+<<<<-]>>>>[-<<<<+>>>>]+>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<<[>>+<<[-]]>[>+<[-]]++>>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<+<[[-]>-<]>[<<<<<<<.>>>>>>>[-]]<<<<<<<<<.>>----.---------.<<.>>----.+++..+++++++++++++.[-]<<[-]]<[>+>+<<-]>>[-<<+>>]+>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<<[>>+>+<<<-]>>>[-<<<+>>>]++++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[>+<[-]]<[>>+<<[-]]>>[<<+>>[-]]<<[[-]>++++++++[<++++>-]<.>++++++++++[>+++++++++++<-]>+.-.<<.>>++++++.------------.---.<<.>++++++[>+++<-]>.<++++++[>----<-]>++.+++++++++++..[-]<<[-]++++++++++.[-]]<[>+>+<<-]>>[-<<+>>]+++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[[-]++++++++++. >+++++++++[>+++++++++<-]>+++.+++++++++++++.++++++++++.------.<++++++++[>>++++<<-]>>.<++++++++++.-.---------.>.<-.+++++++++++.++++++++.---------.>.<-------------.+++++++++++++.----------.>.<++++++++++++.---------------.<+++[>++++++<-]>..>.<----------.+++++++++++.>.<<+++[>------<-]>-.+++++++++++++++++.---.++++++.-------.----------.[-]>[-]<<<.[-]]<[>+>+<<-]>>[-<<+>>]++++>+<[-<->]<[[-]>>-<<]>>[[-]<<+>>]<<[[-]++++++++++.[-]<[-]>]<+<]";
   var pos = 0;
   var len = #src;
   var char;
@@ -20,8 +15,6 @@
   var ptr = 0;
   var ptrmax = 30000 - 1;
 
-
-
   var i = 0;
   while (i < ptrmax) {
     tape[i] = 0;
@@ -61,7 +54,7 @@
       ;
 
       if (char == ".")
-        print(chr(tape[ptr]))
+        write(chr(tape[ptr]))
       ;
 
       if (char == ",") {
@@ -109,4 +102,6 @@
     };
   };
 
-};
\ No newline at end of file
+};
+
+main();
\ No newline at end of file
diff --git a/src/ndspkg/chunk.nim b/src/ndspkg/chunk.nim
index 2307c28..be6d149 100644
--- a/src/ndspkg/chunk.nim
+++ b/src/ndspkg/chunk.nim
@@ -7,7 +7,6 @@ type
   OpCode* = enum
     opReturn, opCall, opCheckArity, opFunctionDef, # functions
     opPop, opPopSA, opPopA # pop
-    opPrint, # print TODO move to native func
     opNegate, opNot # unary
     opAdd, opSubtract, opMultiply, opDivide, # math
     opEqual, opGreater, opLess, # comparison
@@ -18,7 +17,7 @@ type
     opJumpIfFalse, opJump, opLoop, opJumpIfFalsePop, # jumps
     opCreateList, opCreateTable, # collection creation
     opLen, opSetIndex, opGetIndex, # collection operators
-    opChr, opInt, # temporary opcodes for the brainfuck interpreter TODO move to native funcs
+    opPrint, opChr, opInt, opPutchar, # temporary opcodes for the brainfuck interpreter TODO move to native funcs
 
   Chunk* = object
     code*: seq[uint8]
@@ -83,7 +82,7 @@ const simpleInstructions = {
   opEqual, opGreater, opLess,
   opTrue, opFalse, opNil,
   opLen, opSetIndex, opGetIndex,
-  opChr, opInt,
+  opChr, opInt, opPutchar,
 }
 const constantInstructions = {
   opConstant,
diff --git a/src/ndspkg/compiler.nim b/src/ndspkg/compiler.nim
index 98c24ec..ae21c25 100644
--- a/src/ndspkg/compiler.nim
+++ b/src/ndspkg/compiler.nim
@@ -473,12 +473,15 @@ proc unary(comp: Compiler) =
       comp.writeChunk(0, opInt)
     of tkChr:
       comp.writeChunk(0, opChr)
+    of tkPutch:
+      comp.writeChunk(0, opPutchar)
     else:
       discard # unreachable
 
 tkBang.genRule(unary, nop, pcNone)
 tkInt.genRule(unary, nop, pcNone)
 tkChr.genRule(unary, nop, pcNone)
+tkPutch.genRule(unary, nop, pcNone)
 
 proc binary(comp: Compiler) =
   let opType = comp.previous.tokenType
diff --git a/src/ndspkg/scanner.nim b/src/ndspkg/scanner.nim
index 9113451..b1754c7 100644
--- a/src/ndspkg/scanner.nim
+++ b/src/ndspkg/scanner.nim
@@ -19,7 +19,7 @@ type
     tkIdentifier, tkString,
     tkNumber, tkAnd, tkElse, tkFalse, tkFor, tkFunct, tkGoto, tkIf, tkNil,
     tkOr, tkPrint, tkLabel, tkBreak, tkTrue, tkVar, tkWhile,
-    tkChr, tkInt,
+    tkChr, tkInt, tkPutch,
     tkError, tkEof
 
   Token* = object
@@ -128,6 +128,7 @@ const keywords = {
   "while": tkWhile,
   "int": tkInt,
   "chr": tkChr,
+  "write": tkPutch,
 }.toTable
 
 proc canStartIdent(chr: char): bool =
diff --git a/src/ndspkg/types/hashtable.nim b/src/ndspkg/types/hashtable.nim
index 518f08c..4008467 100644
--- a/src/ndspkg/types/hashtable.nim
+++ b/src/ndspkg/types/hashtable.nim
@@ -123,7 +123,7 @@ proc tableFindString*[U, V](tbl: Table[U, V], chars: ptr char, len: int, hash: i
     if entry.entryStatus == esNil:
       return nil
     elif entry.key.len.int == len and entry.key.hash.int == hash and
-      equalMem(chars, entry.key.chars[0].unsafeAddr, len):
+      (len == 0 or equalMem(chars, entry.key.chars[0].unsafeAddr, len)):
         return entry.key
     index = (index + 1).bitand(tbl.cap - 1)
 
diff --git a/src/ndspkg/types/ndstring.nim b/src/ndspkg/types/ndstring.nim
index 320bf98..270aaef 100644
--- a/src/ndspkg/types/ndstring.nim
+++ b/src/ndspkg/types/ndstring.nim
@@ -11,20 +11,26 @@ proc free*(ndStr: var NdString) =
 
 # hashes
 
-proc fnv1a*(ndStr: NdString): int =
+proc fnv1a*(ndStr: NdString): int {.inline.} =
   var hash = 2166136261'u32
   for i in countup(0, ndStr.len.int - 1):
     hash = hash xor (ndStr.chars[i]).uint32
     hash *= 16777619
   return hash.int
 
-proc fnv1a*(str: string): int =
+proc fnv1a*(str: string): int {.inline.} = # SHOULD RETURN THE SAME HASH AS AN NDSTRING WITH THE SAME CONTENTS
   var hash = 2166136261'u32
   for i in countup(0, str.len - 1):
     hash = hash xor (str[i]).uint32
     hash *= 16777619
   return hash.int
 
+proc fnv1a*(str: char): int {.inline.} = # SHOULD RETURN THE SAME AS A 1 LENGTH STRING
+  var hash = 2166136261'u32
+  hash = hash xor str.uint32
+  hash *= 16777619
+  return hash.int
+
 
 # equals
 
@@ -37,25 +43,48 @@ proc newString*(str: string): NdString =
   let strlen = str.len()
   let hash = str.fnv1a()
 
-  let interned = ndStrings.tableFindString(str[0].unsafeAddr, strlen, hash)
-  if interned != nil:
-    return interned
+  if strlen > 0:
+    let interned = ndStrings.tableFindString(str[0].unsafeAddr, strlen, hash)
+    if interned != nil:
+      return interned
+  else:
+    let interned = ndStrings.tableFindString(nil, 0, hash)
+    if interned != nil:
+      return interned
 
   let len = 8 + strlen
   result = cast[NdString](alloc(len))
   result.len = strlen.uint32
   result.hash = hash.uint32
-  copyMem(result.chars[0].unsafeAddr, str[0].unsafeAddr, strlen)
+  if strlen > 0:
+    copyMem(result.chars[0].unsafeAddr, str[0].unsafeAddr, strlen)
 
   discard ndStrings.tableSet(result, nil)
 
+proc newString*(str: char): NdString =
+  let hash = str.fnv1a()
+
+  let interned = ndStrings.tableFindString(str.unsafeAddr, 1, hash)
+  if interned != nil:
+    return interned
+
+  let len = 8 + 1
+  result = cast[NdString](alloc(len))
+  result.len = 1.uint32
+  result.hash = hash.uint32
+  result.chars[0] = str
+
+  discard ndStrings.tableSet(result, nil)
+
+
 proc resetInternedStrings* =
   ndStrings.free()
   ndStrings = newTable[NdString, NdString]()
 
 proc `$`*(ndStr: NdString): string =
   result = newString(ndStr.len.int)
-  copyMem(result[0].unsafeAddr, ndStr.chars[0].unsafeAddr, ndStr.len.int)
+  if ndStr.len.int > 0:
+    copyMem(result[0].unsafeAddr, ndStr.chars[0].unsafeAddr, ndStr.len.int)
 
 proc `&`*(left, right: NdString): NdString =
   # TODO optimize this later when strings will be benchmarked
@@ -65,5 +94,7 @@ proc getLength*(ndStr: NdString): int =
   ndStr.len.int
 
 proc getIndex*(ndStr: NdString, index: int): NdString =
-  # TODO optimize this later
-  newString($($ndStr)[index])
\ No newline at end of file
+  newString(ndStr.chars[index])
+
+proc getIndexAsChar*(ndStr: NdString, index: int): char =
+  ndStr.chars[index]
\ No newline at end of file
diff --git a/src/ndspkg/types/stack.nim b/src/ndspkg/types/stack.nim
index 760cfcc..c797cb6 100644
--- a/src/ndspkg/types/stack.nim
+++ b/src/ndspkg/types/stack.nim
@@ -65,6 +65,12 @@ proc peek*[T](stack: Stack[T]): var T {.inline.} =
       raise newException(Defect, "Stacktop is nil or smaller than start.")
   stack.top[]
 
+proc settip*[T](stack: var Stack[T], newtip: T) {.inline.} =
+  when boundsChecks:
+    if stack.top == nil or stack.top.pless(stack.start):
+      raise newException(Defect, "Stacktop is nil or smaller than start")
+  stack.top[]= newtip
+
 proc deleteTopN*[T](stack: var Stack[T], n: Natural) =
   stack.top = stack.top.psub(sizeof(T) * n)
   when boundsChecks:
diff --git a/src/ndspkg/vm.nim b/src/ndspkg/vm.nim
index 4450aa2..7d1e41a 100644
--- a/src/ndspkg/vm.nim
+++ b/src/ndspkg/vm.nim
@@ -157,7 +157,7 @@ proc run*(chunk: Chunk): InterpretResult =
           runtimeError(res.msg)
           break
       of opPrint:
-        write stdout, $stack.peek()
+        echo $stack.peek()
       of opDefineGlobal:
         let name = readConstant().asString()
         let existed = globals.tableSet(name.fromNdString(), stack.pop())
@@ -253,7 +253,7 @@ proc run*(chunk: Chunk): InterpretResult =
           break
       of opGetIndex:
         let index = stack.pop()
-        let res = stack.peek().getIndex(index)
+        let res = stack.peek().getIndex(index) # getIndex modifies the top value of the stack
         if not res.ok:
           runtimeError(res.msg)
           break
@@ -265,19 +265,31 @@ proc run*(chunk: Chunk): InterpretResult =
           runtimeError(res.msg)
           break
       of opChr:
-        let val = stack.pop()
-        if not val.isFloat() or val.asFloat() > 255f or val.asFloat() < 0f:
-          runtimeError("chr on not float or float out of range")
+        let val = stack.peek()
+        if not val.isFloat():
+          runtimeError("chr on not float")
           break
-        let chr = val.asFloat().int().char()
-        stack.push(($chr).fromNimString())
+        let floatval = val.asFloat()
+        if floatval > 255f or floatval < 0f:
+          runtimeError("chr on a float out of range")
+          break
+        let chr = floatval.char()
+        stack.settip((chr).newString().fromNdString())
       of opInt:
-        let val = stack.pop()
+        let val = stack.peek()
         if not val.isString():
           runtimeError("int on non string")
           break
-        let code = ($val.asString())[0].int().float()
-        stack.push(code.fromFloat())
+        let strval = val.asString()
+        if strval.getLength() == 0:
+          runtimeError("int on empty string")
+          break
+        let code = val.asString().getIndexAsChar(0).float()
+        stack.settip(code.fromFloat())
+      of opPutchar:
+        write stdout, $stack.peek()
+        
+        
 
     when profileInstructions:
       durations[ins] += getMonoTime() - startTime
diff --git a/tests/ampersand.nds b/tests/ampersand.nds
new file mode 100644
index 0000000..3d7d2d7
--- /dev/null
+++ b/tests/ampersand.nds
@@ -0,0 +1,18 @@
+// intended use cases of ampersand:
+
+var x = @[1, 2, 3, 4, 5];
+
+x[0] = 0 & [2] = 0;
+x[5] = 1 & [6] = 0 & [7] = 3 & [7] = 2;
+
+//expect:@[ 0.0, 2.0, 0.0, 4.0, 5.0, 1.0, 0.0, 2.0 ]
+print x;
+
+// not very useful but still must be correct behavior tests:
+
+// change of precedence where interjected
+
+var y = 5 + 1 & * 3;
+//expect:18.0
+print y;
+
diff --git a/tests/break.nds b/tests/break.nds
index 23e3e88..cbb37de 100644
--- a/tests/break.nds
+++ b/tests/break.nds
@@ -1,5 +1,8 @@
 
-print "expect: inner douter";
+// tests for nested scopes, labels, breaking labels and setting the result of block expressions
+
+//expect:inner
+//expect:outer
 { @outer
   { @middle
     { @inner
@@ -11,7 +14,9 @@ print "expect: inner douter";
   print "outer";
 };
 
-print "expect: inner middle outer";
+//expect:inner
+//expect:middle
+//expect:outer
 { @outer
   { @middle
     { @inner
@@ -23,7 +28,7 @@ print "expect: inner middle outer";
   print "outer";
 };
 
-print "expect: nothing";
+// nothing to expect here
 { @outer
   { @middle
     { @inner
@@ -37,7 +42,7 @@ print "expect: nothing";
   print "outer";
 };
 
-print "expect 5";
+//expect:5.0
 
 var f = funct() {
   var y = 1;
@@ -52,7 +57,7 @@ var f = funct() {
 
 print f();
 
-print "expect 15";
+//expect:15.0
 
 f = funct(m, n)
   :result = m + n
@@ -61,7 +66,7 @@ f = funct(m, n)
 print f(f(5, 5), 5);
 
 
-print "expect: 10";
+//expect:10.0
 
 var g = funct()
   :result = {@a
@@ -75,7 +80,7 @@ var g = funct()
 
 print g();
 
-print "expect: 9";
+//expect:9.0
 
 var h = funct()
   :result = {@a
diff --git a/tests/controlflow.nds b/tests/controlflow.nds
new file mode 100644
index 0000000..a6ae279
--- /dev/null
+++ b/tests/controlflow.nds
@@ -0,0 +1,134 @@
+// tests for basic control flow constructs
+
+// if, else
+
+//expect:true
+if (true) {
+  print "true";
+};
+
+if (false) {
+  print "false";
+};
+
+// return the condition if falsy
+
+//expect:nil
+print if (nil) 5;
+
+//expect:false
+print if (false) 5;
+
+// return body if truthy
+
+//expect:5.0
+print if (true) 5;
+
+// return else body if falsey and present
+
+//expect:6.0
+print if (false) 5 else 6;
+
+// but still only return the if body if truthy
+
+//expect:4.0
+print if (true) 4 else 6;
+
+// elseif chains
+
+//expect:4.0
+print if (false) 1 else if (false) 2 else if (false) 3 else if (true) 4 else if (false) 5 else 8;
+
+// falsiness, truthiness
+
+// false and nil are falsey
+
+var uninitialized;
+
+if (false) print "don't see this";
+if (nil) print "don't see this";
+if (uninitialized) print "don't see this";
+
+// the rest of the types are truthy
+
+if (true) print "1";
+if ("") print "2";
+if ("hello") print "3";
+if (0) print "4";
+if (1) print "5";
+if (@[]) print "6";
+if (@["hi"]) print "7";
+if (@{}) print "8";
+if (@{"hi" = 5}) print "9";
+if (funct(n) print n) print "10";
+
+//expect:1
+//expect:2
+//expect:3
+//expect:4
+//expect:5
+//expect:6
+//expect:7
+//expect:8
+//expect:9
+//expect:10
+
+// and, or
+
+// and returns the left one if it's falsey or the right one if the left one is truthy
+
+//expect:false
+print false and 5;
+
+//expect:5.0
+print true and 5;
+
+// or returns the leftmost truthy
+
+//expect:5.0
+print false or false or false or false or 5 or false or 7;
+
+//expect:true
+print true or false;
+
+// while
+
+// basic looping examples
+
+var i = 1;
+
+while (i < 300) {
+  i = i + 1;
+};
+
+print i; //expect:300.0
+
+
+i = 5; 
+while (i > 0) 
+  print i = i - 1
+;
+//expect:4.0
+//expect:3.0
+//expect:2.0
+//expect:1.0
+//expect:0.0
+
+// while returns the result of the last iteration
+
+i = 5;
+var res = while (i > 0)
+  i = i - 1
+;
+
+//expect:0.0
+print res;
+
+// if no iterations are done, it returns nil
+
+res = while (false)
+  i = 6
+;
+
+//expect:nil
+print res;
diff --git a/tests/test.nim b/tests/test.nim
index e2ec4d6..1d397b9 100644
--- a/tests/test.nim
+++ b/tests/test.nim
@@ -1,7 +1,49 @@
 import hashtable
+import ndlist
+
+import os
+import re
+import strutils
+import osproc
 
 testHashtables()
 
-import ndlist
+testNdlist()
+
+var ndsPath = "bin/nds"
+var testsPath = "tests"
+
+proc assembleTestOutput(path: string): string =
+  for line in path.lines:
+    if line.contains(re"//expect:"):
+      result &= line[line.find(re"//expect:") + "//expect:".len()..^1] & "\n"
+
+proc runTest(path: string) =
+  let (output, exitcode) = execCmdEx(ndsPath & " " & path)
+  let expoutput = assembleTestOutput(path)
+  let success = output == expoutput
+  if not success:
+    echo "Nds test failed: " & path
+    echo "expected output:"
+    echo expoutput
+    echo "got output:"
+    echo output
+  else:
+    echo "Test success: " & path
+
+if not dirExists(testsPath):
+  testsPath = "."
+
+if not fileExists(ndsPath):
+  if fileExists(".." / ndsPath):
+    ndsPath = ".." / ndsPath
+  else:
+    echo "Couldn't find nds binary in bin/nds or ../bin/nds, run nimble build first."
+    quit 1
+
+for test in walkDir(testsPath):
+  if test.path.splitFile.ext == ".nds":
+    runTest(test.path)
+
+
 
-testNdlist()
\ No newline at end of file
diff --git a/tests/while.nds b/tests/while.nds
deleted file mode 100644
index ed1503d..0000000
--- a/tests/while.nds
+++ /dev/null
@@ -1,8 +0,0 @@
-
-var i = 1;
-
-while (i < 300) {
-  i = i + 1;
-};
-
-print i;
\ No newline at end of file
diff --git a/tests/while2.nds b/tests/while2.nds
deleted file mode 100644
index 36d1beb..0000000
--- a/tests/while2.nds
+++ /dev/null
@@ -1,4 +0,0 @@
-var i = 5; 
-while (i > 0) 
-  print i = i - 1
-;
\ No newline at end of file