diff --git a/PLATFORM/C/LIB/buffer.lm b/PLATFORM/C/LIB/buffer.lm
deleted file mode 100644
index c345ea4bf..000000000
--- a/PLATFORM/C/LIB/buffer.lm
+++ /dev/null
@@ -1,34 +0,0 @@
-
-
-type Buffer (Buffer( ptr:U8[] , allocated:U64 , capacity:U64 ));
-
-new-buffer := λ(: capacity U64). (: (
-   (let ptr (malloc capacity))
-   (Buffer( (as ptr U8[]) 0_u64 capacity ))
-) Buffer);
-
-.calculate-extension-size := λ(: min-size U64). (: (
-   (let try-size 1024_u64)
-   (while (<( try-size min-size )) (
-      (set try-size (*( try-size 4_u64 )))
-   ))
-   try-size
-) U64);
-
-.extend := λ(: buff Buffer)(: sz U64). (: (
-   (if (<( (+( (.allocated buff) sz )) (.capacity buff) )) (
-      (set buff (Buffer( (.ptr buff) (+( (.allocated buff) sz )) (.capacity buff) )))
-   ) (
-      (let new-sz (.calculate-extension-size( (+( (.allocated buff) sz )) )))
-      (let new-ptr (realloc( (.ptr buff) new-sz )))
-      (set buff (Buffer( (as new-ptr U8[]) (+( (.allocated buff) sz )) new-sz )))
-   ))
-   buff
-) Buffer);
-
-.write := λ(: buff Buffer)(: data U8). (: (
-   (let out-buff (.extend( buff 1_u64 )))
-   (set[]( (as (.ptr out-buff) U8[]) (.allocated buff) data ))
-   out-buff
-) Buffer);
-
diff --git a/PLATFORM/C/LIB/default.lsts b/PLATFORM/C/LIB/default.lsts
index 8c432363c..d454cbdda 100644
--- a/PLATFORM/C/LIB/default.lsts
+++ b/PLATFORM/C/LIB/default.lsts
@@ -26,7 +26,6 @@ import PLATFORM/C/LIB/u64.lsts;
 import PLATFORM/C/LIB/i64.lsts;
 import PLATFORM/C/LIB/f64.lsts;
 import PLATFORM/C/LIB/usize.lsts;
-import PLATFORM/C/LIB/buffer.lm;
 import PLATFORM/C/LIB/string.lm;
 import PLATFORM/C/LIB/string.lsts;
 import PLATFORM/C/LIB/smart-string.lm;
diff --git a/PLATFORM/C/LIB/minimal.lsts b/PLATFORM/C/LIB/minimal.lsts
index 3bbee732b..1be6ad252 100644
--- a/PLATFORM/C/LIB/minimal.lsts
+++ b/PLATFORM/C/LIB/minimal.lsts
@@ -20,7 +20,6 @@ import PLATFORM/C/LIB/u64.lsts;
 import PLATFORM/C/LIB/i32.lsts;
 import PLATFORM/C/LIB/i64.lsts;
 import PLATFORM/C/LIB/usize.lsts;
-import PLATFORM/C/LIB/buffer.lm;
 import PLATFORM/C/LIB/string.lm;
 import PLATFORM/C/LIB/string.lsts;
 import PLATFORM/C/LIB/smart-string.lm;
diff --git a/PLATFORM/C/LIB/string.lm b/PLATFORM/C/LIB/string.lm
index bd9a28acf..6a3ec9372 100644
--- a/PLATFORM/C/LIB/string.lm
+++ b/PLATFORM/C/LIB/string.lm
@@ -9,34 +9,6 @@ tail-string := λ(: x String). (: (
    (+( (as x U8[]) 1_u64 ))
 ) String);
 
-clone-rope := λ(: s S). (: (
-   (let buff (new-buffer 64_u64))
-   (set buff (clone-rope-impl( buff s )))
-   (set buff (.write( buff 0_u8 )))
-   (as (.ptr buff) String)
-) String);
-
-clone-rope-impl := λ(: buff Buffer)(: s S). (: (
-   (match s (
-      ()
-      ( SNil () )
-      ( (SCons( l r )) (
-         (set buff (clone-rope-impl( buff l )))
-         (set buff (clone-rope-impl( buff r )))
-      ))
-      ( (SAtom a) (
-         (let ci 0_u64)
-         (let c ([]( (as a U8[]) ci )))
-         (while (!=( c 0_u8 )) (
-            (set buff (.write( buff c )))
-            (set ci (+( ci 1_u64 )))
-            (set c ([]( (as a U8[]) ci )))
-         ))
-      ))
-   ))
-   buff
-) Buffer);
-
 deep-hash := λ(: key String). (: (
    (let i 0_u64)
    (let hash 0_u64)
diff --git a/PLATFORM/C/LIB/string.lsts b/PLATFORM/C/LIB/string.lsts
index 38684164e..5f94ad374 100644
--- a/PLATFORM/C/LIB/string.lsts
+++ b/PLATFORM/C/LIB/string.lsts
@@ -1,4 +1,34 @@
 
+# TODO: instead do U8 iterator for S
+
+# TODO: deprecate this in favor of Vector
+let clone-rope(s: S): CString = (
+   let out = mk-vector(type(U8), 64);
+   out = clone-rope-impl(s, out);
+   out.move-to(type(CString))
+);
+
+let clone-rope-impl(s: S, out: Vector<U8>): Vector<U8> = (
+   match s {
+      SNil {} => ();
+
+      SCons { l=left, r=right } => (
+         out = clone-rope-impl(l, out);
+         out = clone-rope-impl(r, out);
+      );
+
+      SAtom { a=atom } => (
+         while non-zero(a) {
+            out = out.push(head-string(a));
+            a = tail-string(a);
+         };
+      );
+
+      r => ();
+   };
+   out
+);
+
 let cmp(l: CString, r: CString): Ord = (
    let c = strcmp( (l as U8[]), (r as U8[]) );
    if c < 0_i32 { LessThan }
diff --git a/PLATFORM/C/LIB/u64.lm b/PLATFORM/C/LIB/u64.lm
index 10c65ebb4..340c0b2ce 100644
--- a/PLATFORM/C/LIB/u64.lm
+++ b/PLATFORM/C/LIB/u64.lm
@@ -13,27 +13,6 @@ min := λ(: x U64)(: y U64). (: (
    (if (<=( x y )) x y)
 ) U64);
 
-to-string := λ(: i U64). (: (
-   (let r SNil)
-   (let c 0_u8)
-   (while (not(==( i 0_u64 ))) (
-      (let ci (as (+( (%( i 10_u64 )) 48_u64 )) U8))
-      (set i (/( i 10_u64 )))
-      (set r (SCons(
-         (close(SAtom(clone-rope ci)))
-         (close r)
-      )))
-   ))
-   (if (non-zero r) () (
-      (set r (SAtom '0_s))
-   ))
-   (clone-rope r)
-) String);
-
-to-smart-string := λ(: i U64). (: (
-   (intern(to-string i))
-) SmartString);
-
 deep-hash := λ(: x U64). (: (hash x) U64);
 
 to-u64 := λ(: s String). (: (
diff --git a/PLATFORM/C/LIB/u64.lsts b/PLATFORM/C/LIB/u64.lsts
index 7d05e3b53..15c2fd82b 100644
--- a/PLATFORM/C/LIB/u64.lsts
+++ b/PLATFORM/C/LIB/u64.lsts
@@ -24,3 +24,20 @@ declare-unop( not, raw-type(U64), raw-type(U64), ( l"(!"; x; l")"; ) );
 declare-unop( into-branch-conditional, raw-type(U64), raw-type(BranchConditional), x );
 
 let cmp(l: U64, r: U64): Ord = if l==r then Equal else if l<r then LessThan else GreaterThan;
+
+let to-string(i: U64): CString = (
+   let out = mk-vector(type(U8), 8);
+
+   while i > 0 {
+      let ci = ((i % 10) + 48) as U8;
+      i = i / 10;
+      out = out.push(ci);
+   };
+
+   out.reverse-self();
+   out.move-to(type(CString))
+);
+
+let to-smart-string(i: U64): SmartString = (
+   intern(to-string(i))
+);
diff --git a/PLATFORM/C/LIB/vector.lsts b/PLATFORM/C/LIB/vector.lsts
index 67ce7e3ac..494c5174c 100644
--- a/PLATFORM/C/LIB/vector.lsts
+++ b/PLATFORM/C/LIB/vector.lsts
@@ -33,9 +33,9 @@ let .reserve-additional(v: Vector<t>, additional: U64): Vector<t> = (
 let .push(v: Vector<t>, i: t): Vector<t> = (
    if v.length >= v.capacity {
       let new-cap = if v.capacity == 0 {
-         4
+         4_u64
       } else { # mul 1.5
-         (v.capacity << 1) + v.capacity
+         (v.length >> 1_u64) + v.length
       };
       v = v.realloc(new-cap);
    };
@@ -55,7 +55,7 @@ let .to-vector(l: List<t>): Vector<t> = (
 # shrinks the vector if it has way too many elements. shouldn't be called manually
 let .shrink(v: Vector<t>): Vector<t> = (
     let too-much = v.capacity - v.length;
-    let minimum = (v.length << 1) + v.length; # mul 1.5
+    let minimum = (v.length >> 1) + v.length; # mul 1.5
     if too-much > minimum {
        v = v.realloc(minimum);
     };
@@ -123,6 +123,17 @@ let $"set[]"( v: Vector<t>, i: U64, val: t ): Nil = (
    ()
 );
 
+let .reverse-self(v: Vector<t>): Nil = (
+   let i = 0_u64;
+   while i < (v.length >> 1) {
+      let ri = v.length - i - 1;
+      let temp = v[i];
+      v[i] = v[ri];
+      v[ri] = temp;
+      i = i + 1;
+   };
+);
+
 let .sort(v: Vector<t>): Vector<t> = (
    let n = v.length;
    let i = 0_u64;
@@ -166,6 +177,7 @@ type CString => FromVector<U8>;
 # MAKES INPUT VECTOR INVALID
 let .move-to(self: Vector<U8>, res: Type<CString>): CString = (
    self = self.push(0_u8);
+   self = self.shrink();
    (self.data as U8[]) as CString
 );
 
diff --git a/tests/lib/vector-push-pop.lsts b/tests/lib/vector-push-pop.lsts
new file mode 100644
index 000000000..92981c62a
--- /dev/null
+++ b/tests/lib/vector-push-pop.lsts
@@ -0,0 +1,38 @@
+
+import LIB/minimal.lsts;
+
+let v = mk-vector(type(String), 4);
+
+let ai = 0_u64;
+while ai < 128 {
+   v = v.push(to-smart-string(ai));
+   ai = ai + 1;
+};
+
+assert(v.length == 128);
+let last-cap = v.capacity;
+
+ai = 0_u64;
+while ai < v.length {
+   let x = v[ai];
+   assert(x == to-smart-string(ai));
+   ai = ai + 1;
+};
+
+ai = 0_u64;
+while ai < 100 {
+   v = v.pop().first;
+   ai = ai + 1;
+};
+
+# should have shrunk from the pop() s
+assert(v.capacity < last-cap);
+last-cap = v.capacity;
+
+ai = 0_u64;
+while ai < v.length {
+   let x = v[ai];
+   assert(x == to-smart-string(ai));
+   ai = ai + 1;
+};
+
diff --git a/tests/lib/vector-push-pop.lsts.out b/tests/lib/vector-push-pop.lsts.out
new file mode 100644
index 000000000..e69de29bb