diff --git a/src/hammer.c b/src/hammer.c
index e4addba..5542e80 100644
--- a/src/hammer.c
+++ b/src/hammer.c
@@ -20,6 +20,7 @@
 #include <assert.h>
 #include <string.h>
 #include <stdarg.h>
+#include <ctype.h>
 
 parse_state_t* from(parse_state_t *ps, const size_t index) {
   parse_state_t *ret = g_new(parse_state_t, 1);
@@ -146,7 +147,25 @@ typedef struct {
   uint8_t upper;
 } range_t;
 
-const parser_t* whitespace(const parser_t* p) { return NULL; }
+static parse_result_t* parse_whitespace(void* env, parse_state_t *state) {
+  char c;
+  input_stream_t bak;
+  do {
+    bak = state->input_stream;
+    c = read_bits(&state->input_stream, 8, false);
+    if (state->input_stream.overrun)
+      return NULL;
+  } while (isspace(c));
+  state->input_stream = bak;
+  return do_parse((parser_t*)env, state);
+}
+
+const parser_t* whitespace(const parser_t* p) {
+  parser_t *ret = g_new(parser_t, 1);
+  ret->fn  = parse_whitespace;
+  ret->env = (void*)p;
+  return ret;
+}
 //const parser_t* action(const parser_t* p, /* fptr to action on AST */) { return NULL; }
 
 const parser_t* left_factor_action(const parser_t* p) { return NULL; }
@@ -178,7 +197,7 @@ const parser_t* not_in(const uint8_t *options, int count) {
   for (int i = 0; i < 256; i++)
     charset_set(cs, i, 1);
   for (int i = 0; i < count; i++)
-    charset_set(cs, i, 0);
+    charset_set(cs, options[i], 0);
 
   ret->fn = parse_charset; ret->env = (void*)cs;
   return (const parser_t*)ret;
@@ -225,7 +244,8 @@ static parse_result_t* parse_sequence(void *env, parse_state_t *state) {
     if (NULL == tmp) {
       return NULL;
     } else {
-      g_sequence_append(seq, tmp);
+      if (tmp->ast)
+	g_sequence_append(seq, (void*)tmp->ast);
     }
   }
   parsed_token_t *tok = g_new(parsed_token_t, 1);
@@ -622,22 +642,12 @@ static void test_float32(void) {
 
 
 static void test_whitespace(void) {
-  uint8_t test1[1] = { 'a' };
-  uint8_t test2[2] = { ' ', 'a' };
-  uint8_t test3[3] = { ' ', ' ', 'a' };
-  uint8_t test4[2] = { '\t', 'a' };
-  uint8_t test5[2] = { '_', 'a' };
   const parser_t *whitespace_ = whitespace(ch('a'));
-  parse_result_t *ret1 = parse(whitespace_, test1, 1);
-  parse_result_t *ret2 = parse(whitespace_, test2, 2);
-  parse_result_t *ret3 = parse(whitespace_, test3, 3);
-  parse_result_t *ret4 = parse(whitespace_, test4, 2);
-  parse_result_t *ret5 = parse(whitespace_, test5, 2);
-  g_check_cmpint(ret1->ast->uint, ==, 'a');
-  g_check_cmpint(ret2->ast->uint, ==, 'a');
-  g_check_cmpint(ret3->ast->uint, ==, 'a');
-  g_check_cmpint(ret4->ast->uint, ==, 'a');
-  g_check_failed(ret5);
+  g_check_parse_ok(whitespace_, "a", 1, "s0x61");
+  g_check_parse_ok(whitespace_, " a", 2, "s0x61");
+  g_check_parse_ok(whitespace_, "  a", 3, "s0x61");
+  g_check_parse_ok(whitespace_, "\ta", 2, "s0x61");
+  g_check_parse_failed(whitespace_, "_a", 2);
 }
 
 static void test_action(void) {
@@ -650,23 +660,16 @@ static void test_left_factor_action(void) {
 
 static void test_not_in(void) {
   uint8_t options[3] = { 'a', 'b', 'c' };
-  uint8_t test1[1] = { 'd' };
-  uint8_t test2[1] = { 'a' };
   const parser_t *not_in_ = not_in(options, 3);
-  parse_result_t *ret1 = parse(not_in_, test1, 1);
-  parse_result_t *ret2 = parse(not_in_, test2, 1);
-  g_check_cmpint(ret1->ast->uint, ==, 'd');
-  g_check_failed(ret2);
+  g_check_parse_ok(not_in_, "d", 1, "s0x64");
+  g_check_parse_failed(not_in_, "a", 1);
+
 }
 
 static void test_end_p(void) {
-  uint8_t test1[1] = { 'a' };
-  uint8_t test2[2] = { 'a', 'a' };
   const parser_t *end_p_ = sequence(ch('a'), end_p(), NULL);
-  parse_result_t *ret1 = parse(end_p_, test1, 1);
-  parse_result_t *ret2 = parse(end_p_, test2, 2);
-  g_check_cmpint(ret1->ast->uint, ==, 'a');
-  g_check_failed(ret2);
+  g_check_parse_ok(end_p_, "a", 1, "(s0x61)");
+  g_check_parse_failed(end_p_, "aa", 2);
 }
 
 static void test_nothing_p(void) {
@@ -680,12 +683,12 @@ static void test_sequence(void) {
   const parser_t *sequence_1 = sequence(ch('a'), ch('b'), NULL);
   const parser_t *sequence_2 = sequence(ch('a'), whitespace(ch('b')), NULL);
 
-  g_check_parse_ok(sequence_1, "ab", 2, "(<41> <42>)");
+  g_check_parse_ok(sequence_1, "ab", 2, "(s0x61 s0x62)");
   g_check_parse_failed(sequence_1, "a", 1);
   g_check_parse_failed(sequence_1, "b", 1);
-  g_check_parse_ok(sequence_2, "ab", 2, "(<41> <42>)");
-  g_check_parse_ok(sequence_2, "a b", 3, "(<41> <42>)");
-  g_check_parse_ok(sequence_2, "a  b", 4, "(<41> <42>)");
+  g_check_parse_ok(sequence_2, "ab", 2, "(s0x61 s0x62)");
+  g_check_parse_ok(sequence_2, "a b", 3, "(s0x61 s0x62)");
+  g_check_parse_ok(sequence_2, "a  b", 4, "(s0x61 s0x62)");
   
   //g_check_cmpseq(ret1->ast->
 }
diff --git a/src/pprint.c b/src/pprint.c
index 6aad7b3..cf39c0e 100644
--- a/src/pprint.c
+++ b/src/pprint.c
@@ -99,7 +99,7 @@ static void unamb_sub(const parsed_token_t* tok, struct result_buf *buf) {
     append_buf(buf, tmpbuf, len);
     break;
   case TT_UINT:
-    len = asprintf(&tmpbuf, "s%#lx\n", tok->uint);
+    len = asprintf(&tmpbuf, "s%#lx", tok->uint);
     append_buf(buf, tmpbuf, len);
     break;
   case TT_SEQUENCE: {
@@ -117,8 +117,10 @@ static void unamb_sub(const parsed_token_t* tok, struct result_buf *buf) {
       unamb_sub(subtok, buf);
     }
     append_buf_c(buf, ')');
-  } // TODO: implement this
+  }
+    break;
   default:
+    fprintf(stderr, "Unexpected token type %d\n", tok->token_type);
     g_assert_not_reached();
   }
 }
diff --git a/src/test_suite.h b/src/test_suite.h
index 3c01d3f..47c5ac4 100644
--- a/src/test_suite.h
+++ b/src/test_suite.h
@@ -54,7 +54,7 @@
 #define g_check_parse_ok(parser, input, inp_len, result) {		\
     parse_result_t *res = parse(parser, (const uint8_t*)input, inp_len); \
     if (!res) {								\
-      g_test_message("Parse failed");					\
+      g_test_message("Parse failed on line %d", __LINE__);				\
       g_test_fail();							\
     } else {								\
       char* cres = write_result_unamb(res->ast);			\