[Parser] Simplify the lexer interface (#6319)

The lexer was previously an iterator over tokens, but that expressivity is not
actually used in the parser. Instead, we have `input.h` that adapts the token
iterator interface into an iterface that is actually useful.

As a first step toward simplifying the lexer implementation to no longer be an
iterator over tokens, update its interface by moving the adaptation from input.h
to the lexer itself. This requires extensive changes to the lexer unit tests,
which will not have to change further when we actually simplify the lexer
implementation.

1 files changed, 831 insertions, 1432 deletions

diff --git a/test/gtest/wat-lexer.cpp b/test/gtest/wat-lexer.cpp
index b62644682..8e31b9ab9 100644
--- a/test/gtest/wat-lexer.cpp
+++ b/test/gtest/wat-lexer.cpp
@@ -23,76 +23,57 @@ using namespace wasm::WATParser;
 using namespace std::string_view_literals;
 
 TEST(LexerTest, LexWhitespace) {
-  Token one{"1"sv, IntTok{1, NoSign}};
-  Token two{"2"sv, IntTok{2, NoSign}};
-  Token three{"3"sv, IntTok{3, NoSign}};
-  Token four{"4"sv, IntTok{4, NoSign}};
-  Token five{"5"sv, IntTok{5, NoSign}};
-
   Lexer lexer(" 1\t2\n3\r4 \n\n\t 5 "sv);
 
-  auto it = lexer.begin();
-  ASSERT_NE(it, lexer.end());
-  Token t1 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t2 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t3 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t4 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t5 = *it++;
-  EXPECT_EQ(it, lexer.end());
-
-  EXPECT_EQ(t1, one);
-  EXPECT_EQ(t2, two);
-  EXPECT_EQ(t3, three);
-  EXPECT_EQ(t4, four);
-  EXPECT_EQ(t5, five);
-
-  EXPECT_EQ(lexer.position(t1), (TextPos{1, 1}));
-  EXPECT_EQ(lexer.position(t2), (TextPos{1, 3}));
-  EXPECT_EQ(lexer.position(t3), (TextPos{2, 0}));
-  EXPECT_EQ(lexer.position(t4), (TextPos{2, 2}));
-  EXPECT_EQ(lexer.position(t5), (TextPos{4, 2}));
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{1, 1}));
+  EXPECT_EQ(lexer.takeI32(), 1);
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{1, 3}));
+  EXPECT_EQ(lexer.takeI32(), 2);
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{2, 0}));
+  EXPECT_EQ(lexer.takeI32(), 3);
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{2, 2}));
+  EXPECT_EQ(lexer.takeI32(), 4);
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{4, 2}));
+  EXPECT_EQ(lexer.takeI32(), 5);
+
+  ASSERT_TRUE(lexer.empty());
 }
 
 TEST(LexerTest, LexLineComment) {
-  Token one{"1"sv, IntTok{1, NoSign}};
-  Token six{"6"sv, IntTok{6, NoSign}};
-
   Lexer lexer("1;; whee! 2 3\t4\r5\n6"sv);
 
-  auto it = lexer.begin();
-  Token t1 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t2 = *it++;
-  EXPECT_EQ(it, lexer.end());
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{1, 0}));
+  EXPECT_EQ(lexer.takeI32(), 1);
 
-  EXPECT_EQ(t1, one);
-  EXPECT_EQ(t2, six);
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{2, 0}));
+  EXPECT_EQ(lexer.takeI32(), 6);
 
-  EXPECT_EQ(lexer.position(t1), (TextPos{1, 0}));
-  EXPECT_EQ(lexer.position(t2), (TextPos{2, 0}));
+  EXPECT_TRUE(lexer.empty());
 }
 
 TEST(LexerTest, LexBlockComment) {
-  Token one{"1"sv, IntTok{1, NoSign}};
-  Token six{"6"sv, IntTok{6, NoSign}};
-
   Lexer lexer("1(; whoo! 2\n (; \n3\n ;) 4 (;) 5 ;) \n;)6"sv);
 
-  auto it = lexer.begin();
-  Token t1 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t2 = *it++;
-  EXPECT_EQ(it, lexer.end());
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{1, 0}));
+  EXPECT_EQ(lexer.takeI32(), 1);
 
-  EXPECT_EQ(t1, one);
-  EXPECT_EQ(t2, six);
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_EQ(lexer.position(), (TextPos{5, 2}));
+  EXPECT_EQ(lexer.takeI32(), 6);
 
-  EXPECT_EQ(lexer.position(t1), (TextPos{1, 0}));
-  EXPECT_EQ(lexer.position(t2), (TextPos{5, 2}));
+  EXPECT_TRUE(lexer.empty());
 }
 
 TEST(LexerTest, LexParens) {
@@ -101,1446 +82,864 @@ TEST(LexerTest, LexParens) {
 
   Lexer lexer("(())"sv);
 
-  auto it = lexer.begin();
-  ASSERT_NE(it, lexer.end());
-  Token t1 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t2 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t3 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t4 = *it++;
-  EXPECT_EQ(it, lexer.end());
-
-  EXPECT_EQ(t1, left);
-  EXPECT_EQ(t2, left);
-  EXPECT_EQ(t3, right);
-  EXPECT_EQ(t4, right);
-  EXPECT_TRUE(left.isLParen());
-  EXPECT_TRUE(right.isRParen());
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_TRUE(lexer.takeLParen());
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_TRUE(lexer.takeLParen());
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_TRUE(lexer.takeRParen());
+
+  ASSERT_FALSE(lexer.empty());
+  EXPECT_TRUE(lexer.takeRParen());
+
+  EXPECT_TRUE(lexer.empty());
 }
 
 TEST(LexerTest, LexInt) {
-  {
-    Lexer lexer("0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0"sv, IntTok{0, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0"sv, IntTok{0, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0"sv, IntTok{0, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"1"sv, IntTok{1, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+1"sv, IntTok{1, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-1"sv, IntTok{-1ull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0010"sv, IntTok{10, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0010"sv, IntTok{10, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0010"sv, IntTok{-10ull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("9999"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"9999"sv, IntTok{9999, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+9999"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+9999"sv, IntTok{9999, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-9999"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-9999"sv, IntTok{-9999ull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("12_34"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"12_34"sv, IntTok{1234, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("1_2_3_4"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"1_2_3_4"sv, IntTok{1234, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("_1234"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("1234_"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("12__34"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("12cd56"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("18446744073709551615"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"18446744073709551615"sv, IntTok{-1ull, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    // 64-bit unsigned overflow!
-    Lexer lexer("18446744073709551616"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"18446744073709551616"sv,
-                   FloatTok{{}, 18446744073709551616.}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+9223372036854775807"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+9223372036854775807"sv, IntTok{INT64_MAX, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+9223372036854775808"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+9223372036854775808"sv,
-                   IntTok{uint64_t(INT64_MAX) + 1, Pos}};
-    ;
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-9223372036854775808"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-9223372036854775808"sv, IntTok{uint64_t(INT64_MIN), Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-9223372036854775809"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-9223372036854775809"sv,
-                   IntTok{uint64_t(INT64_MIN) - 1, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
+  EXPECT_EQ(Lexer("0"sv).takeU8(), uint8_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeI8(), uint8_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeI16(), uint16_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeU32(), uint32_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeI32(), uint32_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeU64(), uint64_t(0));
+  EXPECT_EQ(Lexer("0"sv).takeI64(), uint64_t(0));
+
+  EXPECT_FALSE(Lexer("+0"sv).takeU8());
+  EXPECT_EQ(Lexer("+0"sv).takeI8(), uint8_t(0));
+
+  EXPECT_FALSE(Lexer("-0"sv).takeU8());
+  EXPECT_EQ(Lexer("-0"sv).takeI8(), uint8_t(0));
+
+  EXPECT_EQ(Lexer("1"sv).takeU8(), uint8_t(1));
+  EXPECT_EQ(Lexer("1"sv).takeI8(), uint8_t(1));
+
+  EXPECT_FALSE(Lexer("+1"sv).takeU8());
+  EXPECT_EQ(Lexer("+1"sv).takeI8(), uint8_t(1));
+
+  EXPECT_FALSE(Lexer("-1"sv).takeU8());
+  EXPECT_EQ(Lexer("-1").takeI8(), uint8_t(-1));
+
+  EXPECT_EQ(Lexer("0010"sv).takeU8(), uint8_t(10));
+  EXPECT_EQ(Lexer("0010"sv).takeI8(), uint8_t(10));
+
+  EXPECT_FALSE(Lexer("+0010"sv).takeU8());
+  EXPECT_EQ(Lexer("+0010"sv).takeI8(), uint8_t(10));
+
+  EXPECT_FALSE(Lexer("-0010"sv).takeU8());
+  EXPECT_EQ(Lexer("-0010"sv).takeI8(), uint8_t(-10));
+
+  EXPECT_FALSE(Lexer("9999"sv).takeU8());
+  EXPECT_EQ(Lexer("9999"sv).takeI16(), uint16_t(9999));
+  EXPECT_EQ(Lexer("9999"sv).takeU32(), uint32_t(9999));
+  EXPECT_EQ(Lexer("9999"sv).takeI32(), uint32_t(9999));
+
+  EXPECT_FALSE(Lexer("+9999"sv).takeU32());
+  EXPECT_EQ(Lexer("+9999"sv).takeI32(), uint32_t(9999));
+
+  EXPECT_FALSE(Lexer("-9999"sv).takeU32());
+  EXPECT_EQ(Lexer("-9999"sv).takeI32(), uint32_t(-9999));
+
+  EXPECT_EQ(Lexer("12_34"sv).takeU32(), uint32_t(1234));
+  EXPECT_EQ(Lexer("12_34"sv).takeI32(), uint32_t(1234));
+
+  EXPECT_EQ(Lexer("1_2_3_4"sv).takeU32(), uint32_t(1234));
+  EXPECT_EQ(Lexer("1_2_3_4"sv).takeI32(), uint32_t(1234));
+
+  EXPECT_FALSE(Lexer("_1234"sv).takeU32());
+  EXPECT_FALSE(Lexer("_1234"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("1234_"sv).takeU32());
+  EXPECT_FALSE(Lexer("1234_"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("12__34"sv).takeU32());
+  EXPECT_FALSE(Lexer("12__34"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("12cd56"sv).takeU32());
+  EXPECT_FALSE(Lexer("12cd56"sv).takeI32());
+
+  EXPECT_EQ(Lexer("18446744073709551615"sv).takeU64(), uint64_t(-1));
+  EXPECT_EQ(Lexer("18446744073709551615"sv).takeI64(), uint64_t(-1));
+
+  // 64-bit overflow!
+  EXPECT_FALSE(Lexer("18446744073709551616"sv).takeU64());
+  EXPECT_FALSE(Lexer("18446744073709551616"sv).takeI64());
+
+  EXPECT_FALSE(Lexer("+9223372036854775807"sv).takeU64());
+  EXPECT_EQ(Lexer("+9223372036854775807"sv).takeI64(), INT64_MAX);
+
+  EXPECT_EQ(Lexer("9223372036854775808"sv).takeU64(), uint64_t(INT64_MAX) + 1);
+  EXPECT_EQ(Lexer("9223372036854775808"sv).takeI64(), uint64_t(INT64_MAX) + 1);
+
+  EXPECT_FALSE(Lexer("+9223372036854775808"sv).takeU64());
+  EXPECT_FALSE(Lexer("+9223372036854775808"sv).takeI64());
+
+  EXPECT_FALSE(Lexer("-9223372036854775808"sv).takeU64());
+  EXPECT_EQ(Lexer("-9223372036854775808"sv).takeI64(), uint64_t(INT64_MIN));
+
+  EXPECT_FALSE(Lexer("-9223372036854775809"sv).takeU64());
+  EXPECT_FALSE(Lexer("-9223372036854775809"sv).takeI64());
 }
 
 TEST(LexerTest, LexHexInt) {
-  {
-    Lexer lexer("0x0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x0"sv, IntTok{0, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0x0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0x0"sv, IntTok{0, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0x0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0x0"sv, IntTok{0, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x1"sv, IntTok{1, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0x1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0x1"sv, IntTok{1, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0x1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0x1"sv, IntTok{-1ull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x0010"sv, IntTok{16, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0x0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0x0010"sv, IntTok{16, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0x0010"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0x0010"sv, IntTok{-16ull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0xabcdef"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0xabcdef"sv, IntTok{0xabcdef, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0xABCDEF"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0xABCDEF"sv, IntTok{0xabcdef, Pos}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0xAbCdEf"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0xAbCdEf"sv, IntTok{-0xabcdefull, Neg}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x12_34"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x12_34"sv, IntTok{0x1234, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x1_2_3_4"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x1_2_3_4"sv, IntTok{0x1234, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("_0x1234"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x_1234"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x1234_"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x12__34"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0xg"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x120x34"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
+  EXPECT_EQ(Lexer("0x0"sv).takeU8(), uint8_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeI8(), uint8_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeI16(), uint16_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeU32(), uint32_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeI32(), uint32_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeU64(), uint64_t(0));
+  EXPECT_EQ(Lexer("0x0"sv).takeI64(), uint64_t(0));
+
+  EXPECT_FALSE(Lexer("+0x0"sv).takeU8());
+  EXPECT_EQ(Lexer("+0x0"sv).takeI8(), uint8_t(0));
+
+  EXPECT_FALSE(Lexer("-0x0"sv).takeU8());
+  EXPECT_EQ(Lexer("-0x0"sv).takeI8(), uint8_t(0));
+
+  EXPECT_EQ(Lexer("0x1"sv).takeU8(), uint8_t(1));
+  EXPECT_EQ(Lexer("0x1"sv).takeI8(), uint8_t(1));
+
+  EXPECT_FALSE(Lexer("+0x1"sv).takeU8());
+  EXPECT_EQ(Lexer("+0x1"sv).takeI8(), uint8_t(1));
+
+  EXPECT_FALSE(Lexer("-0x1"sv).takeU8());
+  EXPECT_EQ(Lexer("-0x1").takeI8(), uint8_t(-1));
+
+  EXPECT_EQ(Lexer("0x0010"sv).takeU8(), uint8_t(16));
+  EXPECT_EQ(Lexer("0x0010"sv).takeI8(), uint8_t(16));
+
+  EXPECT_FALSE(Lexer("+0x0010"sv).takeU8());
+  EXPECT_EQ(Lexer("+0x0010"sv).takeI8(), uint8_t(16));
+
+  EXPECT_FALSE(Lexer("-0x0010"sv).takeU8());
+  EXPECT_EQ(Lexer("-0x0010"sv).takeI8(), uint8_t(-16));
+
+  EXPECT_FALSE(Lexer("0xabcdef"sv).takeU8());
+  EXPECT_EQ(Lexer("0xabcdef"sv).takeU32(), uint32_t(0xabcdef));
+  EXPECT_EQ(Lexer("0xabcdef"sv).takeI32(), uint32_t(0xabcdef));
+
+  EXPECT_FALSE(Lexer("+0xABCDEF"sv).takeU32());
+  EXPECT_EQ(Lexer("+0xABCDEF"sv).takeI32(), uint32_t(0xabcdef));
+
+  EXPECT_FALSE(Lexer("-0xAbCdEf"sv).takeU32());
+  EXPECT_EQ(Lexer("-0xAbCdEf"sv).takeI32(), uint32_t(-0xabcdef));
+
+  EXPECT_EQ(Lexer("0x12_34"sv).takeU32(), uint32_t(0x1234));
+  EXPECT_EQ(Lexer("0x12_34"sv).takeI32(), uint32_t(0x1234));
+
+  EXPECT_EQ(Lexer("0x1_2_3_4"sv).takeU32(), uint32_t(0x1234));
+  EXPECT_EQ(Lexer("0x1_2_3_4"sv).takeI32(), uint32_t(0x1234));
+
+  EXPECT_FALSE(Lexer("_0x1234"sv).takeU32());
+  EXPECT_FALSE(Lexer("_0x1234"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("0x_1234"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x_1234"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("0x1234_"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x1234_"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("0x12__34"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x12__34"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("0xg"sv).takeU32());
+  EXPECT_FALSE(Lexer("0xg"sv).takeI32());
+
+  EXPECT_FALSE(Lexer("0x120x34"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x120x34"sv).takeI32());
 }
 
 TEST(LexerTest, ClassifyInt) {
-  {
-    Lexer lexer("0"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    ASSERT_TRUE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0ull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0ull);
-    EXPECT_EQ(*lexer->getU<uint32_t>(), 0u);
-    EXPECT_EQ(*lexer->getS<int32_t>(), 0);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0u);
-    EXPECT_EQ(*lexer->getF64(), 0.0);
-    EXPECT_EQ(*lexer->getF32(), 0.0);
-    EXPECT_FALSE(std::signbit(*lexer->getF64()));
-    EXPECT_FALSE(std::signbit(*lexer->getF32()));
-  }
-  {
-    Lexer lexer("+0"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0ull);
-    EXPECT_EQ(*lexer->getS<int32_t>(), 0);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0u);
-    EXPECT_EQ(*lexer->getF64(), 0.0);
-    EXPECT_EQ(*lexer->getF32(), 0.0);
-    EXPECT_FALSE(std::signbit(*lexer->getF64()));
-    EXPECT_FALSE(std::signbit(*lexer->getF32()));
-  }
-  {
-    Lexer lexer("-0"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0ull);
-    EXPECT_EQ(*lexer->getS<int32_t>(), 0);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0u);
-    EXPECT_EQ(*lexer->getF64(), -0.0);
-    EXPECT_EQ(*lexer->getF32(), -0.0);
-    ASSERT_TRUE(std::signbit(*lexer->getF64()));
-    ASSERT_TRUE(std::signbit(*lexer->getF32()));
-  }
-  {
-    Lexer lexer("0x7fff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    ASSERT_TRUE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0x7fffffffull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x7fffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x7fffffffull);
-    EXPECT_EQ(*lexer->getU<uint32_t>(), 0x7fffffffu);
-    EXPECT_EQ(*lexer->getS<int32_t>(), 0x7fffffff);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0x7fffffffu);
-    EXPECT_EQ(*lexer->getF64(), 0x7fffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x7fffffff.p0f);
-  }
-  {
-    Lexer lexer("0x8000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    ASSERT_TRUE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0x80000000ull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x80000000ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x80000000ull);
-    EXPECT_EQ(*lexer->getU<uint32_t>(), 0x80000000u);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0x80000000u);
-    EXPECT_EQ(*lexer->getF64(), 0x80000000.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x80000000.p0f);
-  }
-  {
-    Lexer lexer("+0x7fff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x7fffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x7fffffffull);
-    EXPECT_EQ(*lexer->getS<int32_t>(), 0x7fffffff);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0x7fffffffu);
-    EXPECT_EQ(*lexer->getF64(), 0x7fffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x7fffffff.p0f);
-  }
-  {
-    Lexer lexer("+0x8000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x80000000ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x80000000ull);
-    EXPECT_EQ(*lexer->getF64(), 0x80000000.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x80000000.p0f);
-  }
-  {
-    Lexer lexer("-0x8000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    ASSERT_TRUE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), -0x80000000ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), -0x80000000ull);
-    EXPECT_EQ(*lexer->getS<int32_t>(), -0x7fffffffll - 1);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), -0x80000000u);
-    EXPECT_EQ(*lexer->getF64(), -0x80000000.p0);
-    EXPECT_EQ(*lexer->getF32(), -0x80000000.p0f);
-  }
-  {
-    Lexer lexer("-0x8000_0001"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), -0x80000001ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), -0x80000001ull);
-    EXPECT_EQ(*lexer->getF64(), -0x80000001.p0);
-    EXPECT_EQ(*lexer->getF32(), -0x80000001.p0f);
-  }
-  {
-    Lexer lexer("0xffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    ASSERT_TRUE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    ASSERT_TRUE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0xffffffffull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0xffffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0xffffffffull);
-    EXPECT_EQ(*lexer->getU<uint32_t>(), 0xffffffffu);
-    EXPECT_EQ(*lexer->getI<uint32_t>(), 0xffffffffu);
-    EXPECT_EQ(*lexer->getF64(), 0xffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0xffffffff.p0f);
-  }
-  {
-    Lexer lexer("0x1_0000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0x100000000ull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x100000000ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x100000000ull);
-    EXPECT_EQ(*lexer->getF64(), 0x100000000.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x100000000.p0f);
-  }
-  {
-    Lexer lexer("+0xffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0xffffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0xffffffffull);
-    EXPECT_EQ(*lexer->getF64(), 0xffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0xffffffff.p0f);
-  }
-  {
-    Lexer lexer("+0x1_0000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x100000000ll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x100000000ull);
-    EXPECT_EQ(*lexer->getF64(), 0x100000000.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x100000000.p0f);
-  }
-  {
-    Lexer lexer("0x7fff_ffff_ffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0x7fffffffffffffffull);
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x7fffffffffffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x7fffffffffffffffull);
-    EXPECT_EQ(*lexer->getF64(), 0x7fffffffffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x7fffffffffffffff.p0f);
-  }
-  {
-    Lexer lexer("+0x7fff_ffff_ffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), 0x7fffffffffffffffll);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0x7fffffffffffffffull);
-    EXPECT_EQ(*lexer->getF64(), 0x7fffffffffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0x7fffffffffffffff.p0f);
-  }
-  {
-    Lexer lexer("-0x8000_0000_0000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    ASSERT_TRUE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getS<int64_t>(), -0x7fffffffffffffffll - 1);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), -0x8000000000000000ull);
-    EXPECT_EQ(*lexer->getF64(), -0x8000000000000000.p0);
-    EXPECT_EQ(*lexer->getF32(), -0x8000000000000000.p0f);
-  }
-  {
-    Lexer lexer("0xffff_ffff_ffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    ASSERT_TRUE(lexer->getU<uint64_t>());
-    EXPECT_FALSE(lexer->getS<int64_t>());
-    ASSERT_TRUE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getU<uint64_t>(), 0xffffffffffffffffull);
-    EXPECT_EQ(*lexer->getI<uint64_t>(), 0xffffffffffffffffull);
-    EXPECT_EQ(*lexer->getF64(), 0xffffffffffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0xffffffffffffffff.p0f);
-  }
-  {
-    Lexer lexer("+0xffff_ffff_ffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-
-    EXPECT_FALSE(lexer->getU<uint64_t>());
-    EXPECT_FALSE(lexer->getS<int64_t>());
-    EXPECT_FALSE(lexer->getI<uint64_t>());
-    EXPECT_FALSE(lexer->getU<uint32_t>());
-    EXPECT_FALSE(lexer->getS<int32_t>());
-    EXPECT_FALSE(lexer->getI<uint32_t>());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-
-    EXPECT_EQ(*lexer->getF64(), 0xffffffffffffffff.p0);
-    EXPECT_EQ(*lexer->getF32(), 0xffffffffffffffff.p0f);
-  }
+  ASSERT_FALSE(Lexer("0"sv).empty());
+  ASSERT_TRUE(Lexer("0"sv).takeU64());
+  ASSERT_TRUE(Lexer("0"sv).takeI64());
+  ASSERT_TRUE(Lexer("0"sv).takeU32());
+  ASSERT_TRUE(Lexer("0"sv).takeI32());
+  ASSERT_TRUE(Lexer("0"sv).takeF64());
+  ASSERT_TRUE(Lexer("0"sv).takeF32());
+  EXPECT_EQ(*Lexer("0"sv).takeU64(), 0ull);
+  EXPECT_EQ(*Lexer("0"sv).takeI64(), 0ull);
+  EXPECT_EQ(*Lexer("0"sv).takeU32(), 0u);
+  EXPECT_EQ(*Lexer("0"sv).takeI32(), 0u);
+  EXPECT_EQ(*Lexer("0"sv).takeF64(), 0.0);
+  EXPECT_EQ(*Lexer("0"sv).takeF32(), 0.0);
+  EXPECT_FALSE(std::signbit(*Lexer("0"sv).takeF64()));
+  EXPECT_FALSE(std::signbit(*Lexer("0"sv).takeF32()));
+
+  ASSERT_FALSE(Lexer("+0"sv).empty());
+  EXPECT_FALSE(Lexer("+0"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0"sv).takeU32());
+  ASSERT_TRUE(Lexer("+0"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0"sv).takeI64(), 0ull);
+  EXPECT_EQ(*Lexer("+0"sv).takeI32(), 0u);
+  EXPECT_EQ(*Lexer("+0"sv).takeF64(), 0.0);
+  EXPECT_EQ(*Lexer("+0"sv).takeF32(), 0.0);
+  EXPECT_FALSE(std::signbit(*Lexer("+0"sv).takeF64()));
+  EXPECT_FALSE(std::signbit(*Lexer("+0"sv).takeF32()));
+
+  ASSERT_FALSE(Lexer("-0"sv).empty());
+  EXPECT_FALSE(Lexer("-0"sv).takeU64());
+  ASSERT_TRUE(Lexer("-0"sv).takeI64());
+  EXPECT_FALSE(Lexer("-0"sv).takeU32());
+  ASSERT_TRUE(Lexer("-0"sv).takeI32());
+  ASSERT_TRUE(Lexer("-0"sv).takeF64());
+  ASSERT_TRUE(Lexer("-0"sv).takeF32());
+  EXPECT_EQ(*Lexer("-0"sv).takeI64(), 0ull);
+  EXPECT_EQ(*Lexer("-0"sv).takeI32(), 0u);
+  EXPECT_EQ(*Lexer("-0"sv).takeF64(), -0.0);
+  EXPECT_EQ(*Lexer("-0"sv).takeF32(), -0.0);
+  ASSERT_TRUE(std::signbit(*Lexer("-0"sv).takeF64()));
+  ASSERT_TRUE(std::signbit(*Lexer("-0"sv).takeF32()));
+
+  ASSERT_FALSE(Lexer("0x7fff_ffff"sv).empty());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeI64());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeU32());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("0x7fff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeU64(), 0x7fffffffull);
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeI64(), 0x7fffffffull);
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeU32(), 0x7fffffffu);
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeI32(), 0x7fffffffu);
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeF64(), 0x7fffffff.p0);
+  EXPECT_EQ(*Lexer("0x7fff_ffff"sv).takeF32(), 0x7fffffff.p0f);
+
+  ASSERT_FALSE(Lexer("0x8000_0000"sv).empty());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeI64());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeU32());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("0x8000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeU64(), 0x80000000ull);
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeI64(), 0x80000000ull);
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeU32(), 0x80000000u);
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeI32(), 0x80000000u);
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeF64(), 0x80000000.p0);
+  EXPECT_EQ(*Lexer("0x8000_0000"sv).takeF32(), 0x80000000.p0f);
+
+  ASSERT_FALSE(Lexer("+0x7fff_ffff"sv).empty());
+  EXPECT_FALSE(Lexer("+0x7fff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0x7fff_ffff"sv).takeU32());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0x7fff_ffff"sv).takeI64(), 0x7fffffffull);
+  EXPECT_EQ(*Lexer("+0x7fff_ffff"sv).takeI32(), 0x7fffffffu);
+  EXPECT_EQ(*Lexer("+0x7fff_ffff"sv).takeF64(), 0x7fffffff.p0);
+  EXPECT_EQ(*Lexer("+0x7fff_ffff"sv).takeF32(), 0x7fffffff.p0f);
+
+  ASSERT_FALSE(Lexer("+0x8000_0000"sv).empty());
+  EXPECT_FALSE(Lexer("+0x8000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0x8000_0000"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0x8000_0000"sv).takeU32());
+  EXPECT_FALSE(Lexer("+0x8000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0x8000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0x8000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0x8000_0000"sv).takeI64(), 0x80000000ull);
+  EXPECT_EQ(*Lexer("+0x8000_0000"sv).takeF64(), 0x80000000.p0);
+  EXPECT_EQ(*Lexer("+0x8000_0000"sv).takeF32(), 0x80000000.p0f);
+
+  ASSERT_FALSE(Lexer("-0x8000_0000"sv).empty());
+  EXPECT_FALSE(Lexer("-0x8000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("-0x8000_0000"sv).takeI64());
+  EXPECT_FALSE(Lexer("-0x8000_0000"sv).takeU32());
+  ASSERT_TRUE(Lexer("-0x8000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("-0x8000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("-0x8000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("-0x8000_0000"sv).takeI64(), -0x80000000ull);
+  EXPECT_EQ(*Lexer("-0x8000_0000"sv).takeI32(), -0x80000000u);
+  EXPECT_EQ(*Lexer("-0x8000_0000"sv).takeF64(), -0x80000000.p0);
+  EXPECT_EQ(*Lexer("-0x8000_0000"sv).takeF32(), -0x80000000.p0f);
+
+  ASSERT_FALSE(Lexer("-0x8000_0001"sv).empty());
+  EXPECT_FALSE(Lexer("-0x8000_0001"sv).takeU64());
+  ASSERT_TRUE(Lexer("-0x8000_0001"sv).takeI64());
+  EXPECT_FALSE(Lexer("-0x8000_0001"sv).takeU32());
+  EXPECT_FALSE(Lexer("-0x8000_0001"sv).takeI32());
+  ASSERT_TRUE(Lexer("-0x8000_0001"sv).takeF64());
+  ASSERT_TRUE(Lexer("-0x8000_0001"sv).takeF32());
+  EXPECT_EQ(*Lexer("-0x8000_0001"sv).takeI64(), -0x80000001ull);
+  EXPECT_EQ(*Lexer("-0x8000_0001"sv).takeF64(), -0x80000001.p0);
+  EXPECT_EQ(*Lexer("-0x8000_0001"sv).takeF32(), -0x80000001.p0f);
+
+  ASSERT_FALSE(Lexer("0xffff_ffff"sv).empty());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeI64());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeU32());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("0xffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeU64(), 0xffffffffull);
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeI64(), 0xffffffffull);
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeU32(), 0xffffffffu);
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeI32(), 0xffffffffu);
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeF64(), 0xffffffff.p0);
+  EXPECT_EQ(*Lexer("0xffff_ffff"sv).takeF32(), 0xffffffff.p0f);
+
+  ASSERT_FALSE(Lexer("0x1_0000_0000"sv).empty());
+  ASSERT_TRUE(Lexer("0x1_0000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("0x1_0000_0000"sv).takeI64());
+  EXPECT_FALSE(Lexer("0x1_0000_0000"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x1_0000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("0x1_0000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("0x1_0000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("0x1_0000_0000"sv).takeU64(), 0x100000000ull);
+  EXPECT_EQ(*Lexer("0x1_0000_0000"sv).takeI64(), 0x100000000ull);
+  EXPECT_EQ(*Lexer("0x1_0000_0000"sv).takeF64(), 0x100000000.p0);
+  EXPECT_EQ(*Lexer("0x1_0000_0000"sv).takeF32(), 0x100000000.p0f);
+
+  ASSERT_FALSE(Lexer("+0xffff_ffff"sv).empty());
+  EXPECT_FALSE(Lexer("+0xffff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0xffff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0xffff_ffff"sv).takeU32());
+  EXPECT_FALSE(Lexer("+0xffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0xffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0xffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0xffff_ffff"sv).takeI64(), 0xffffffffull);
+  EXPECT_EQ(*Lexer("+0xffff_ffff"sv).takeF64(), 0xffffffff.p0);
+  EXPECT_EQ(*Lexer("+0xffff_ffff"sv).takeF32(), 0xffffffff.p0f);
+
+  ASSERT_FALSE(Lexer("+0x1_0000_0000"sv).empty());
+  EXPECT_FALSE(Lexer("+0x1_0000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0x1_0000_0000"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0x1_0000_0000"sv).takeU32());
+  EXPECT_FALSE(Lexer("+0x1_0000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0x1_0000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0x1_0000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0x1_0000_0000"sv).takeI64(), 0x100000000ull);
+  EXPECT_EQ(*Lexer("+0x1_0000_0000"sv).takeF64(), 0x100000000.p0);
+  EXPECT_EQ(*Lexer("+0x1_0000_0000"sv).takeF32(), 0x100000000.p0f);
+
+  ASSERT_FALSE(Lexer("0x7fff_ffff_ffff_ffff"sv).empty());
+  ASSERT_TRUE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeU32());
+  EXPECT_FALSE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("0x7fff_ffff_ffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("0x7fff_ffff_ffff_ffff"sv).takeU64(), 0x7fffffffffffffffull);
+  EXPECT_EQ(*Lexer("0x7fff_ffff_ffff_ffff"sv).takeI64(), 0x7fffffffffffffffull);
+  EXPECT_EQ(*Lexer("0x7fff_ffff_ffff_ffff"sv).takeF64(), 0x7fffffffffffffff.p0);
+  EXPECT_EQ(*Lexer("0x7fff_ffff_ffff_ffff"sv).takeF32(),
+            0x7fffffffffffffff.p0f);
+
+  ASSERT_FALSE(Lexer("+0x7fff_ffff_ffff_ffff"sv).empty());
+  EXPECT_FALSE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeU32());
+  EXPECT_FALSE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0x7fff_ffff_ffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0x7fff_ffff_ffff_ffff"sv).takeI64(),
+            0x7fffffffffffffffull);
+  EXPECT_EQ(*Lexer("+0x7fff_ffff_ffff_ffff"sv).takeF64(),
+            0x7fffffffffffffff.p0);
+  EXPECT_EQ(*Lexer("+0x7fff_ffff_ffff_ffff"sv).takeF32(),
+            0x7fffffffffffffff.p0f);
+
+  ASSERT_FALSE(Lexer("-0x8000_0000_0000_0000"sv).empty());
+  EXPECT_FALSE(Lexer("-0x8000_0000_0000_0000"sv).takeU64());
+  ASSERT_TRUE(Lexer("-0x8000_0000_0000_0000"sv).takeI64());
+  EXPECT_FALSE(Lexer("-0x8000_0000_0000_0000"sv).takeU32());
+  EXPECT_FALSE(Lexer("-0x8000_0000_0000_0000"sv).takeI32());
+  ASSERT_TRUE(Lexer("-0x8000_0000_0000_0000"sv).takeF64());
+  ASSERT_TRUE(Lexer("-0x8000_0000_0000_0000"sv).takeF32());
+  EXPECT_EQ(*Lexer("-0x8000_0000_0000_0000"sv).takeI64(),
+            -0x8000000000000000ull);
+  EXPECT_EQ(*Lexer("-0x8000_0000_0000_0000"sv).takeF64(),
+            -0x8000000000000000.p0);
+  EXPECT_EQ(*Lexer("-0x8000_0000_0000_0000"sv).takeF32(),
+            -0x8000000000000000.p0f);
+
+  ASSERT_FALSE(Lexer("0xffff_ffff_ffff_ffff"sv).empty());
+  ASSERT_TRUE(Lexer("0xffff_ffff_ffff_ffff"sv).takeU64());
+  ASSERT_TRUE(Lexer("0xffff_ffff_ffff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("0xffff_ffff_ffff_ffff"sv).takeU32());
+  EXPECT_FALSE(Lexer("0xffff_ffff_ffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("0xffff_ffff_ffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("0xffff_ffff_ffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("0xffff_ffff_ffff_ffff"sv).takeU64(), 0xffffffffffffffffull);
+  EXPECT_EQ(*Lexer("0xffff_ffff_ffff_ffff"sv).takeI64(), 0xffffffffffffffffull);
+  EXPECT_EQ(*Lexer("0xffff_ffff_ffff_ffff"sv).takeF64(), 0xffffffffffffffff.p0);
+  EXPECT_EQ(*Lexer("0xffff_ffff_ffff_ffff"sv).takeF32(),
+            0xffffffffffffffff.p0f);
+
+  ASSERT_FALSE(Lexer("+0xffff_ffff_ffff_ffff"sv).empty());
+  EXPECT_FALSE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeU64());
+  EXPECT_FALSE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeI64());
+  EXPECT_FALSE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeU32());
+  EXPECT_FALSE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeI32());
+  ASSERT_TRUE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeF64());
+  ASSERT_TRUE(Lexer("+0xffff_ffff_ffff_ffff"sv).takeF32());
+  EXPECT_EQ(*Lexer("+0xffff_ffff_ffff_ffff"sv).takeF64(),
+            0xffffffffffffffff.p0);
+  EXPECT_EQ(*Lexer("+0xffff_ffff_ffff_ffff"sv).takeF32(),
+            0xffffffffffffffff.p0f);
 }
 
 TEST(LexerTest, LexFloat) {
-  {
-    Lexer lexer("42"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42"sv, IntTok{42, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42."sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42."sv, FloatTok{{}, 42.}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.5"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.5"sv, FloatTok{{}, 42.5}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42e0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42e0"sv, FloatTok{{}, 42e0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.e1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.e1"sv, FloatTok{{}, 42.e1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42E1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42E1"sv, FloatTok{{}, 42E1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42e+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42e+2"sv, FloatTok{{}, 42e+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.E-02"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.E-02"sv, FloatTok{{}, 42.E-02}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.0e0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.0e0"sv, FloatTok{{}, 42.0e0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.0E1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.0E1"sv, FloatTok{{}, 42.0E1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.0e+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.0e+2"sv, FloatTok{{}, 42.0e+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("42.0E-2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"42.0E-2"sv, FloatTok{{}, 42.0E-2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+42.0e+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+42.0e+2"sv, FloatTok{{}, +42.0e+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-42.0e+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-42.0e+2"sv, FloatTok{{}, -42.0e+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("4_2.0_0e+0_2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"4_2.0_0e+0_2"sv, FloatTok{{}, 42.00e+02}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42.junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42.0junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42.Ejunk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42.e-junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42.e-10junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("+"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42e"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42eABC"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42e0xABC"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("+-42"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("-+42"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42e+-0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42e-+0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42p0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("42P0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
+  EXPECT_EQ(Lexer("42"sv).takeF32(), 42.0f);
+  EXPECT_EQ(Lexer("42"sv).takeF64(), 42.0);
+
+  EXPECT_EQ(Lexer("42.5"sv).takeF32(), 42.5f);
+  EXPECT_EQ(Lexer("42.5"sv).takeF64(), 42.5);
+
+  EXPECT_EQ(Lexer("42e0"sv).takeF32(), 42e0f);
+  EXPECT_EQ(Lexer("42e0"sv).takeF64(), 42e0);
+
+  EXPECT_EQ(Lexer("42.e1"sv).takeF32(), 42.e1f);
+  EXPECT_EQ(Lexer("42.e1"sv).takeF64(), 42.e1);
+
+  EXPECT_EQ(Lexer("42E1"sv).takeF32(), 42E1f);
+  EXPECT_EQ(Lexer("42E1"sv).takeF64(), 42E1);
+
+  EXPECT_EQ(Lexer("42e+2"sv).takeF32(), 42e+2f);
+  EXPECT_EQ(Lexer("42e+2"sv).takeF64(), 42e+2);
+
+  EXPECT_EQ(Lexer("42.E-02"sv).takeF32(), 42.E-02f);
+  EXPECT_EQ(Lexer("42.E-02"sv).takeF64(), 42.E-02);
+
+  EXPECT_EQ(Lexer("42.0e0"sv).takeF32(), 42.0e0f);
+  EXPECT_EQ(Lexer("42.0e0"sv).takeF64(), 42.0e0);
+
+  EXPECT_EQ(Lexer("42.0E1"sv).takeF32(), 42.0E1f);
+  EXPECT_EQ(Lexer("42.0E1"sv).takeF64(), 42.0E1);
+
+  EXPECT_EQ(Lexer("42.0e+2"sv).takeF32(), 42.0e+2f);
+  EXPECT_EQ(Lexer("42.0e+2"sv).takeF64(), 42.0e+2);
+
+  EXPECT_EQ(Lexer("42.0E-2"sv).takeF32(), 42.0E-2f);
+  EXPECT_EQ(Lexer("42.0E-2"sv).takeF64(), 42.0E-2);
+
+  EXPECT_EQ(Lexer("+42.0e+2"sv).takeF32(), +42.0e+2f);
+  EXPECT_EQ(Lexer("+42.0e+2"sv).takeF64(), +42.0e+2);
+
+  EXPECT_EQ(Lexer("-42.0e+2"sv).takeF32(), -42.0e+2f);
+  EXPECT_EQ(Lexer("-42.0e+2"sv).takeF64(), -42.0e+2);
+
+  EXPECT_EQ(Lexer("4_2.0_0e+0_2"sv).takeF32(), 42.00e+02f);
+  EXPECT_EQ(Lexer("4_2.0_0e+0_2"sv).takeF64(), 42.00e+02);
+
+  EXPECT_FALSE(Lexer("+junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("+junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42.junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42.junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42.0junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42.0junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42.Ejunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42.Ejunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42.e-junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42.e-junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42.e-10junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("42.e-10junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("+"sv).takeF32());
+  EXPECT_FALSE(Lexer("+"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42e"sv).takeF32());
+  EXPECT_FALSE(Lexer("42e"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42eABC"sv).takeF32());
+  EXPECT_FALSE(Lexer("42eABC"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42e0xABC"sv).takeF32());
+  EXPECT_FALSE(Lexer("42e0xABC"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("+-42"sv).takeF32());
+  EXPECT_FALSE(Lexer("+-42"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("-+42"sv).takeF32());
+  EXPECT_FALSE(Lexer("-+42"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42e+-0"sv).takeF32());
+  EXPECT_FALSE(Lexer("42e+-0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42e-+0"sv).takeF32());
+  EXPECT_FALSE(Lexer("42e-+0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42p0"sv).takeF32());
+  EXPECT_FALSE(Lexer("42p0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("42P0"sv).takeF32());
+  EXPECT_FALSE(Lexer("42P0"sv).takeF64());
 }
 
 TEST(LexerTest, LexHexFloat) {
-  {
-    Lexer lexer("0x4B"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B"sv, IntTok{0x4B, NoSign}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B."sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B."sv, FloatTok{{}, 0x4Bp0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.5"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.5"sv, FloatTok{{}, 0x4B.5p0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4Bp0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4Bp0"sv, FloatTok{{}, 0x4Bp0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.p1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.p1"sv, FloatTok{{}, 0x4B.p1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4BP1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4BP1"sv, FloatTok{{}, 0x4BP1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4Bp+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4Bp+2"sv, FloatTok{{}, 0x4Bp+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.P-02"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.P-02"sv, FloatTok{{}, 0x4B.P-02}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.0p0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.0p0"sv, FloatTok{{}, 0x4B.0p0}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.0P1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.0P1"sv, FloatTok{{}, 0x4B.0P1}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.0p+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.0p+2"sv, FloatTok{{}, 0x4B.0p+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4B.0P-2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4B.0P-2"sv, FloatTok{{}, 0x4B.0P-2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+0x4B.0p+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+0x4B.0p+2"sv, FloatTok{{}, +0x4B.0p+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-0x4B.0p+2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-0x4B.0p+2"sv, FloatTok{{}, -0x4B.0p+2}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4_2.0_0p+0_2"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"0x4_2.0_0p+0_2"sv, FloatTok{{}, 0x42.00p+02}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("0x4Bjunk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.0junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.Pjunk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.p-junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.p-10junk"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("+0x"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4Bp"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4BpABC"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4Bp0xABC"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x+0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("+-0x4B"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("-+0x4B"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4Bp+-0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4Bp-+0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.e+0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("0x4B.E-0"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
+
+  EXPECT_EQ(Lexer("0x4B"sv).takeF32(), 0x4Bp0f);
+  EXPECT_EQ(Lexer("0x4B"sv).takeF64(), 0x4Bp0);
+
+  EXPECT_EQ(Lexer("0x4B."sv).takeF32(), 0x4B.p0f);
+  EXPECT_EQ(Lexer("0x4B."sv).takeF64(), 0x4B.p0);
+
+  EXPECT_EQ(Lexer("0x4B.5"sv).takeF32(), 0x4B.5p0f);
+  EXPECT_EQ(Lexer("0x4B.5"sv).takeF64(), 0x4B.5p0);
+
+  EXPECT_EQ(Lexer("0x4Bp0"sv).takeF32(), 0x4Bp0f);
+  EXPECT_EQ(Lexer("0x4Bp0"sv).takeF64(), 0x4Bp0);
+
+  EXPECT_EQ(Lexer("0x4B.p1"sv).takeF32(), 0x4B.p1f);
+  EXPECT_EQ(Lexer("0x4B.p1"sv).takeF64(), 0x4B.p1);
+
+  EXPECT_EQ(Lexer("0x4BP1"sv).takeF32(), 0x4BP1f);
+  EXPECT_EQ(Lexer("0x4BP1"sv).takeF64(), 0x4BP1);
+
+  EXPECT_EQ(Lexer("0x4Bp+2"sv).takeF32(), 0x4Bp+2f);
+  EXPECT_EQ(Lexer("0x4Bp+2"sv).takeF64(), 0x4Bp+2);
+
+  EXPECT_EQ(Lexer("0x4B.P-02"sv).takeF32(), 0x4B.P-02f);
+  EXPECT_EQ(Lexer("0x4B.P-02"sv).takeF64(), 0x4B.P-02);
+
+  EXPECT_EQ(Lexer("0x4B.0p0"sv).takeF32(), 0x4B.0p0f);
+  EXPECT_EQ(Lexer("0x4B.0p0"sv).takeF64(), 0x4B.0p0);
+
+  EXPECT_EQ(Lexer("0x4B.0P1"sv).takeF32(), 0x4B.0P1f);
+  EXPECT_EQ(Lexer("0x4B.0P1"sv).takeF64(), 0x4B.0P1);
+
+  EXPECT_EQ(Lexer("0x4B.0p+2"sv).takeF32(), 0x4B.0p+2f);
+  EXPECT_EQ(Lexer("0x4B.0p+2"sv).takeF64(), 0x4B.0p+2);
+
+  EXPECT_EQ(Lexer("0x4B.0P-2"sv).takeF32(), 0x4B.0P-2f);
+  EXPECT_EQ(Lexer("0x4B.0P-2"sv).takeF64(), 0x4B.0P-2);
+
+  EXPECT_EQ(Lexer("+0x4B.0p+2"sv).takeF32(), +0x4B.0p+2f);
+  EXPECT_EQ(Lexer("+0x4B.0p+2"sv).takeF64(), +0x4B.0p+2);
+
+  EXPECT_EQ(Lexer("-0x4B.0p+2"sv).takeF32(), -0x4B.0p+2f);
+  EXPECT_EQ(Lexer("-0x4B.0p+2"sv).takeF64(), -0x4B.0p+2);
+
+  EXPECT_EQ(Lexer("0x4_2.0_0p+0_2"sv).takeF32(), 0x42.00p+02f);
+  EXPECT_EQ(Lexer("0x4_2.0_0p+0_2"sv).takeF64(), 0x42.00p+02);
+
+  EXPECT_FALSE(Lexer("0x4Bjunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4Bjunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.0junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.0junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.Pjunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.Pjunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.p-junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.p-junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.p-10junk"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.p-10junk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("+0x"sv).takeF32());
+  EXPECT_FALSE(Lexer("+0x"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4Bp"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4Bp"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4BpABC"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4BpABC"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4Bp0xABC"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4Bp0xABC"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x+0"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x+0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("+-0x4B"sv).takeF32());
+  EXPECT_FALSE(Lexer("+-0x4B"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("-+0x4B"sv).takeF32());
+  EXPECT_FALSE(Lexer("-+0x4B"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4Bp+-0"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4Bp+-0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4Bp-+0"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4Bp-+0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.e+0"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.e+0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("0x4B.E-0"sv).takeF32());
+  EXPECT_FALSE(Lexer("0x4B.E-0"sv).takeF64());
 }
 
 TEST(LexerTest, LexInfinity) {
-  {
-    Lexer lexer("inf"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"inf"sv, FloatTok{{}, INFINITY}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+inf"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+inf"sv, FloatTok{{}, INFINITY}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-inf"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-inf"sv, FloatTok{{}, -INFINITY}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("infjunk"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"infjunk"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("Inf"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("INF"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("infinity"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"infinity"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
+  EXPECT_EQ(Lexer("inf"sv).takeF32(), INFINITY);
+  EXPECT_EQ(Lexer("inf"sv).takeF64(), INFINITY);
+
+  EXPECT_EQ(Lexer("+inf"sv).takeF32(), INFINITY);
+  EXPECT_EQ(Lexer("+inf"sv).takeF64(), INFINITY);
+
+  EXPECT_EQ(Lexer("-inf"sv).takeF32(), -INFINITY);
+  EXPECT_EQ(Lexer("-inf"sv).takeF64(), -INFINITY);
+
+  EXPECT_FALSE(Lexer("infjunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("infjunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("Inf"sv).takeF32());
+  EXPECT_FALSE(Lexer("Inf"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("INF"sv).takeF32());
+  EXPECT_FALSE(Lexer("INF"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("infinity"sv).takeF32());
+  EXPECT_FALSE(Lexer("infinity"sv).takeF64());
 }
 
 TEST(LexerTest, LexNan) {
-  const double posNan = std::copysign(NAN, 1.0);
-  const double negNan = std::copysign(NAN, -1.0);
-  {
-    Lexer lexer("nan"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan"sv, FloatTok{{}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+nan"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+nan"sv, FloatTok{{}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-nan"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-nan"sv, FloatTok{{}, negNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x01"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x01"sv, FloatTok{{1}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("+nan:0x01"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"+nan:0x01"sv, FloatTok{{1}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("-nan:0x01"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"-nan:0x01"sv, FloatTok{{1}, negNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x1234"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x1234"sv, FloatTok{{0x1234}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0xf_ffff_ffff_ffff"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0xf_ffff_ffff_ffff"sv,
-                   FloatTok{{0xfffffffffffff}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nanjunk"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nanjunk", KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0xjunk"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0xjunk"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:-0x1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:-0x1"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:+0x1"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:+0x1"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x0"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x0"sv, FloatTok{{0}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x10_0000_0000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x10_0000_0000_0000"sv,
-                   FloatTok{{0x10000000000000}, posNan}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("nan:0x1_0000_0000_0000_0000"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"nan:0x1_0000_0000_0000_0000"sv, KeywordTok{}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("NAN"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("NaN"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
+  ASSERT_TRUE(Lexer("nan"sv).takeF32());
+  ASSERT_TRUE(Lexer("nan"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("+nan"sv).takeF32());
+  ASSERT_TRUE(Lexer("+nan"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("-nan"sv).takeF32());
+  ASSERT_TRUE(Lexer("-nan"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("nan:0x01"sv).takeF32());
+  ASSERT_TRUE(Lexer("nan:0x01"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("+nan:0x01"sv).takeF32());
+  ASSERT_TRUE(Lexer("+nan:0x01"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("-nan:0x01"sv).takeF64());
+  ASSERT_TRUE(Lexer("-nan:0x01"sv).takeF64());
+
+  ASSERT_TRUE(Lexer("nan:0x1234"sv).takeF64());
+  ASSERT_TRUE(Lexer("nan:0x1234"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0xf_ffff_ffff_ffff"sv).takeF32());
+  EXPECT_TRUE(Lexer("nan:0xf_ffff_ffff_ffff"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nanjunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("nanjunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0x"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:0x"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0xjunk"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:0xjunk"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:-0x1"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:-0x1"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:+0x1"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:+0x1"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0x0"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:0x0"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0x10_0000_0000_0000"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:0x10_0000_0000_0000"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("nan:0x1_0000_0000_0000_0000"sv).takeF32());
+  EXPECT_FALSE(Lexer("nan:0x1_0000_0000_0000_0000"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("NAN"sv).takeF32());
+  EXPECT_FALSE(Lexer("NAN"sv).takeF64());
+
+  EXPECT_FALSE(Lexer("NaN"sv).takeF32());
+  EXPECT_FALSE(Lexer("NaN"sv).takeF64());
 }
 
-TEST(LexerTest, ClassifyFloat) {
-  constexpr int signif64 = 52;
-  constexpr int signif32 = 23;
-  constexpr uint64_t payloadMask64 = (1ull << signif64) - 1;
-  constexpr uint32_t payloadMask32 = (1u << signif32) - 1;
-  constexpr uint64_t dnanDefault = 1ull << (signif64 - 1);
-  constexpr uint32_t fnanDefault = 1u << (signif32 - 1);
-  {
-    Lexer lexer("340282346638528859811704183484516925440."sv);
-    ASSERT_FALSE(lexer.empty());
-    ASSERT_TRUE(lexer->getF64());
-    EXPECT_TRUE(lexer->getF32());
-    EXPECT_EQ(*lexer->getF64(), FLT_MAX);
-    EXPECT_EQ(*lexer->getF32(), FLT_MAX);
-  }
-  {
-    Lexer lexer("17976931348623157081452742373170435679807056752584499659891747"
-                "68031572607800285387605895586327668781715404589535143824642343"
-                "21326889464182768467546703537516986049910576551282076245490090"
-                "38932894407586850845513394230458323690322294816580855933212334"
-                "8274797826204144723168738177180919299881250404026184124858368"
-                "."sv);
-    ASSERT_FALSE(lexer.empty());
-    ASSERT_TRUE(lexer->getF64());
-    ASSERT_TRUE(lexer->getF32());
-    EXPECT_EQ(*lexer->getF64(), DBL_MAX);
-    EXPECT_EQ(*lexer->getF32(), INFINITY);
-  }
-  {
-    Lexer lexer("nan");
-    ASSERT_FALSE(lexer.empty());
+constexpr int signif32 = 23;
+constexpr int signif64 = 52;
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
-    EXPECT_TRUE(std::isnan(d));
-    EXPECT_FALSE(std::signbit(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, dnanDefault);
+uint32_t payload(float f) {
+  uint32_t x;
+  static_assert(sizeof(f) == sizeof(x));
+  memcpy(&x, &f, sizeof(f));
+  return x & ((1u << signif32) - 1);
+}
+
+uint64_t payload(double d) {
+  uint64_t x;
+  static_assert(sizeof(d) == sizeof(x));
+  memcpy(&x, &d, sizeof(d));
+  return x & ((1ull << signif64) - 1);
+}
 
-    ASSERT_TRUE(lexer->getF32());
-    float f = *lexer->getF32();
+constexpr uint32_t fnanDefault = 1u << (signif32 - 1);
+constexpr uint64_t dnanDefault = 1ull << (signif64 - 1);
+
+TEST(LexerTest, ClassifyFloat) {
+  auto flt_max = "340282346638528859811704183484516925440."sv;
+  EXPECT_EQ(Lexer(flt_max).takeF32(), FLT_MAX);
+  EXPECT_EQ(Lexer(flt_max).takeF64(), FLT_MAX);
+
+  auto dbl_max =
+    "17976931348623157081452742373170435679807056752584499659891747"
+    "68031572607800285387605895586327668781715404589535143824642343"
+    "21326889464182768467546703537516986049910576551282076245490090"
+    "38932894407586850845513394230458323690322294816580855933212334"
+    "8274797826204144723168738177180919299881250404026184124858368"
+    "."sv;
+  EXPECT_EQ(Lexer(dbl_max).takeF32(), INFINITY);
+  EXPECT_EQ(Lexer(dbl_max).takeF64(), DBL_MAX);
+
+  {
+    auto nan = "nan"sv;
+    ASSERT_TRUE(Lexer(nan).takeF32());
+    float f = *Lexer(nan).takeF32();
     EXPECT_TRUE(std::isnan(f));
     EXPECT_FALSE(std::signbit(f));
-    uint32_t fbits;
-    memcpy(&fbits, &f, sizeof(fbits));
-    EXPECT_EQ(fbits & payloadMask32, fnanDefault);
+    EXPECT_EQ(payload(f), fnanDefault);
+
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
+    EXPECT_TRUE(std::isnan(d));
+    EXPECT_FALSE(std::signbit(d));
+    EXPECT_EQ(payload(d), dnanDefault);
   }
   {
-    Lexer lexer("-nan");
-    ASSERT_FALSE(lexer.empty());
+    auto nan = "-nan"sv;
+    ASSERT_TRUE(Lexer(nan).takeF32());
+    float f = *Lexer(nan).takeF32();
+    EXPECT_TRUE(std::isnan(f));
+    EXPECT_TRUE(std::signbit(f));
+    EXPECT_EQ(payload(f), fnanDefault);
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
     EXPECT_TRUE(std::isnan(d));
     EXPECT_TRUE(std::signbit(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, dnanDefault);
-
-    ASSERT_TRUE(lexer->getF32());
-    float f = *lexer->getF32();
-    EXPECT_TRUE(std::isnan(f));
-    EXPECT_TRUE(std::signbit(f));
-    uint32_t fbits;
-    memcpy(&fbits, &f, sizeof(fbits));
-    EXPECT_EQ(fbits & payloadMask32, fnanDefault);
+    EXPECT_EQ(payload(d), dnanDefault);
   }
   {
-    Lexer lexer("+nan");
-    ASSERT_FALSE(lexer.empty());
+    auto nan = "+nan"sv;
+    ASSERT_TRUE(Lexer(nan).takeF32());
+    float f = *Lexer(nan).takeF32();
+    EXPECT_TRUE(std::isnan(f));
+    EXPECT_FALSE(std::signbit(f));
+    EXPECT_EQ(payload(f), fnanDefault);
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
     EXPECT_TRUE(std::isnan(d));
     EXPECT_FALSE(std::signbit(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, dnanDefault);
-
-    ASSERT_TRUE(lexer->getF32());
-    float f = *lexer->getF32();
-    EXPECT_TRUE(std::isnan(f));
-    EXPECT_FALSE(std::signbit(f));
-    uint32_t fbits;
-    memcpy(&fbits, &f, sizeof(fbits));
-    EXPECT_EQ(fbits & payloadMask32, fnanDefault);
+    EXPECT_EQ(payload(d), dnanDefault);
   }
   {
-    Lexer lexer("nan:0x1234");
-    ASSERT_FALSE(lexer.empty());
+    auto nan = "nan:0x1234"sv;
+    ASSERT_TRUE(Lexer(nan).takeF32());
+    float f = *Lexer(nan).takeF32();
+    EXPECT_TRUE(std::isnan(f));
+    EXPECT_FALSE(std::signbit(f));
+    EXPECT_EQ(payload(f), uint32_t(0x1234));
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
     EXPECT_TRUE(std::isnan(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, 0x1234ull);
-
-    ASSERT_TRUE(lexer->getF32());
-    float f = *lexer->getF32();
-    EXPECT_TRUE(std::isnan(f));
-    uint32_t fbits;
-    memcpy(&fbits, &f, sizeof(fbits));
-    EXPECT_EQ(fbits & payloadMask32, 0x1234u);
+    EXPECT_FALSE(std::signbit(d));
+    EXPECT_EQ(payload(d), uint64_t(0x1234));
   }
   {
-    Lexer lexer("nan:0x7FFFFF");
-    ASSERT_FALSE(lexer.empty());
+    auto nan = "nan:0x7FFFFF"sv;
+    ASSERT_TRUE(Lexer(nan).takeF32());
+    float f = *Lexer(nan).takeF32();
+    EXPECT_TRUE(std::isnan(f));
+    EXPECT_FALSE(std::signbit(f));
+    EXPECT_EQ(payload(f), uint32_t(0x7FFFFF));
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
     EXPECT_TRUE(std::isnan(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, 0x7fffffull);
-
-    ASSERT_TRUE(lexer->getF32());
-    float f = *lexer->getF32();
-    EXPECT_TRUE(std::isnan(f));
-    uint32_t fbits;
-    memcpy(&fbits, &f, sizeof(fbits));
-    EXPECT_EQ(fbits & payloadMask32, 0x7fffffu);
+    EXPECT_FALSE(std::signbit(d));
+    EXPECT_EQ(payload(d), uint64_t(0x7FFFFF));
   }
   {
-    Lexer lexer("nan:0x800000");
-    ASSERT_FALSE(lexer.empty());
+    auto nan = "nan:0x800000"sv;
+    EXPECT_FALSE(Lexer(nan).takeF32());
 
-    ASSERT_TRUE(lexer->getF64());
-    double d = *lexer->getF64();
+    ASSERT_TRUE(Lexer(nan).takeF64());
+    double d = *Lexer(nan).takeF64();
     EXPECT_TRUE(std::isnan(d));
-    uint64_t dbits;
-    memcpy(&dbits, &d, sizeof(dbits));
-    EXPECT_EQ(dbits & payloadMask64, 0x800000ull);
-
-    ASSERT_FALSE(lexer->getF32());
+    EXPECT_FALSE(std::signbit(d));
+    EXPECT_EQ(payload(d), uint64_t(0x800000));
   }
-  {
-    Lexer lexer("nan:0x0");
-    ASSERT_FALSE(lexer.empty());
 
-    ASSERT_FALSE(lexer->getF64());
-    ASSERT_FALSE(lexer->getF32());
+  {
+    auto nan = "nan:0x0"sv;
+    EXPECT_FALSE(Lexer(nan).takeF32());
+    EXPECT_FALSE(Lexer(nan).takeF64());
   }
 }
 
 TEST(LexerTest, LexIdent) {
-  {
-    Lexer lexer("$09azAZ!#$%&'*+-./:<=>?@\\^_`|~"sv);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"$09azAZ!#$%&'*+-./:<=>?@\\^_`|~"sv, IdTok{}};
-    EXPECT_EQ(*lexer, expected);
-    EXPECT_TRUE(lexer->getID());
-    EXPECT_EQ(*lexer->getID(), "09azAZ!#$%&'*+-./:<=>?@\\^_`|~"sv);
-  }
-  {
-    Lexer lexer("$[]{}"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("$abc[]"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("$"sv);
-    EXPECT_TRUE(lexer.empty());
-  }
+  EXPECT_EQ(Lexer("$09azAZ!#$%&'*+-./:<=>?@\\^_`|~"sv).takeID(),
+            wasm::Name("09azAZ!#$%&'*+-./:<=>?@\\^_`|~"sv));
+  EXPECT_FALSE(Lexer("$[]{}"sv).takeID());
+  EXPECT_FALSE(Lexer("$abc[]"sv).takeID());
+  EXPECT_FALSE(Lexer("$"sv).takeID());
 
   // String IDs
-  {
-    Lexer lexer("$\"\"");
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"$\"\""sv, IdTok{true, std::nullopt}};
-    EXPECT_EQ(*lexer, expected);
-    EXPECT_TRUE(lexer->getID());
-    EXPECT_EQ(*lexer->getID(), ""sv);
-  }
-  {
-    Lexer lexer("$\"hello\"");
-    ASSERT_FALSE(lexer.empty());
-    Token expected{"$\"hello\""sv, IdTok{true, std::nullopt}};
-    EXPECT_EQ(*lexer, expected);
-    EXPECT_TRUE(lexer->getID());
-    EXPECT_EQ(*lexer->getID(), "hello"sv);
-  }
-  {
-    // _$_£_€_𐍈_
-    auto unicode = "$\"_\\u{24}_\\u{00a3}_\\u{20AC}_\\u{10348}_\""sv;
-    Lexer lexer(unicode);
-    ASSERT_FALSE(lexer.empty());
-    std::string escaped{"_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_"};
-    Token expected{unicode, IdTok{true, {escaped}}};
-    EXPECT_EQ(*lexer, expected);
-  }
+  EXPECT_EQ(Lexer("$\"\""sv).takeID(), wasm::Name(""sv));
+  EXPECT_EQ(Lexer("$\"hello\""sv).takeID(), wasm::Name("hello"sv));
+  // _$_£_€_𐍈_
+  EXPECT_EQ(Lexer("$\"_\\u{24}_\\u{00a3}_\\u{20AC}_\\u{10348}_\""sv).takeID(),
+            wasm::Name("_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_"sv));
 }
 
 TEST(LexerTest, LexString) {
-  {
-    auto pangram = "\"The quick brown fox jumps over the lazy dog\""sv;
-    Lexer lexer(pangram);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{pangram, StringTok{{}}};
-    EXPECT_EQ(*lexer, expected);
-    EXPECT_TRUE(lexer->getString());
-    EXPECT_EQ(*lexer->getString(),
-              "The quick brown fox jumps over the lazy dog"sv);
-  }
-  {
-    auto chars = "\"`~!@#$%^&*()_-+0123456789|,.<>/?;:'\""sv;
-    Lexer lexer(chars);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{chars, StringTok{{}}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    auto escapes = "\"_\\t_\\n_\\r_\\\\_\\\"_\\'_\""sv;
-    Lexer lexer(escapes);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{escapes, StringTok{{"_\t_\n_\r_\\_\"_'_"}}};
-    EXPECT_EQ(*lexer, expected);
-    EXPECT_TRUE(lexer->getString());
-    EXPECT_EQ(*lexer->getString(), "_\t_\n_\r_\\_\"_'_"sv);
-  }
-  {
-    auto escapes = "\"_\\00_\\07_\\20_\\5A_\\7F_\\ff_\\ffff_\""sv;
-    Lexer lexer(escapes);
-    ASSERT_FALSE(lexer.empty());
-    std::string escaped{"_\0_\7_ _Z_\x7f_\xff_\xff"
-                        "ff_"sv};
-    Token expected{escapes, StringTok{{escaped}}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    // _$_£_€_𐍈_
-    auto unicode = "\"_\\u{24}_\\u{00a3}_\\u{20AC}_\\u{10348}_\""sv;
-    Lexer lexer(unicode);
-    ASSERT_FALSE(lexer.empty());
-    std::string escaped{"_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_"};
-    Token expected{unicode, StringTok{{escaped}}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    // _$_£_€_𐍈_
-    auto unicode = "\"_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_\""sv;
-    Lexer lexer(unicode);
-    ASSERT_FALSE(lexer.empty());
-    Token expected{unicode, StringTok{{}}};
-    EXPECT_EQ(*lexer, expected);
-  }
-  {
-    Lexer lexer("\"unterminated"sv);
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"unescaped nul\0\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"unescaped U+19\x19\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"unescaped U+7f\x7f\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"\\ stray backslash\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"short \\f hex escape\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"bad hex \\gg\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"empty unicode \\u{}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"not unicode \\u{abcdefg}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"extra chars \\u{123(}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"unpaired surrogate unicode crimes \\u{d800}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"more surrogate unicode crimes \\u{dfff}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
-  {
-    Lexer lexer("\"too big \\u{110000}\"");
-    ASSERT_TRUE(lexer.empty());
-  }
+  using namespace std::string_literals;
+  EXPECT_EQ(
+    Lexer("\"The quick brown fox jumps over the lazy dog\""sv).takeString(),
+    "The quick brown fox jumps over the lazy dog");
+  EXPECT_EQ(Lexer("\"`~!@#$%^&*()_-+0123456789|,.<>/?;:'\""sv).takeString(),
+            "`~!@#$%^&*()_-+0123456789|,.<>/?;:'");
+  EXPECT_EQ(Lexer("\"_\\t_\\n_\\r_\\\\_\\\"_\\'_\""sv).takeString(),
+            "_\t_\n_\r_\\_\"_\'_");
+  EXPECT_EQ(Lexer("\"_\\00_\\07_\\20_\\5A_\\7F_\\ff_\\ffff_\""sv).takeString(),
+            "_\0_\7_ _Z_\x7f_\xff_\xff"s + "ff_"s);
+  // _$_£_€_𐍈_
+  EXPECT_EQ(
+    Lexer("\"_\\u{24}_\\u{00a3}_\\u{20AC}_\\u{10348}_\""sv).takeString(),
+    "_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_"s);
+  EXPECT_EQ(
+    Lexer("\"_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_\""sv).takeString(),
+    "_$_\xC2\xA3_\xE2\x82\xAC_\xF0\x90\x8D\x88_"s);
+
+  EXPECT_FALSE(Lexer("\"unterminated"sv).takeString());
+  EXPECT_FALSE(Lexer("\"unescaped nul\0\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"unescaped U+19\x19\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"unescaped U+7f\x7f\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"\\ stray backslash\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"short \\f hex escape\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"bad hex \\gg\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"empty unicode \\u{}\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"not unicode \\u{abcdefg}\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"extra chars \\u{123(}\""sv).takeString());
+  EXPECT_FALSE(
+    Lexer("\"unpaired surrogate unicode crimes \\u{d800}\""sv).takeString());
+  EXPECT_FALSE(
+    Lexer("\"more surrogate unicode crimes \\u{dfff}\""sv).takeString());
+  EXPECT_FALSE(Lexer("\"too big \\u{110000}\""sv).takeString());
 }
 
 TEST(LexerTest, LexKeywords) {
-  Token module{"module"sv, KeywordTok{}};
-  Token type{"type"sv, KeywordTok{}};
-  Token func{"func"sv, KeywordTok{}};
-  Token import{"import"sv, KeywordTok{}};
-  Token reserved{"rEsErVeD"sv, KeywordTok{}};
-
   Lexer lexer("module type func import rEsErVeD");
-
-  auto it = lexer.begin();
-  ASSERT_NE(it, lexer.end());
-  Token t1 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t2 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t3 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t4 = *it++;
-  ASSERT_NE(it, lexer.end());
-  Token t5 = *it++;
-  EXPECT_EQ(it, lexer.end());
-
-  EXPECT_EQ(t1, module);
-  EXPECT_EQ(t2, type);
-  EXPECT_EQ(t3, func);
-  EXPECT_EQ(t4, import);
-  EXPECT_EQ(t5, reserved);
-
-  EXPECT_TRUE(t1.getKeyword());
-  EXPECT_EQ(*t1.getKeyword(), "module"sv);
+  ASSERT_EQ(lexer.takeKeyword(), "module"sv);
+  ASSERT_EQ(lexer.takeKeyword(), "type"sv);
+  ASSERT_EQ(lexer.takeKeyword(), "func"sv);
+  ASSERT_EQ(lexer.takeKeyword(), "import"sv);
+  ASSERT_EQ(lexer.takeKeyword(), "rEsErVeD"sv);
+  ASSERT_TRUE(lexer.empty());
 }