internal/cgen/base/token-public.h - third_party/wuffs - Git at Google

 // Copyright 2020 The Wuffs Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    https://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 // ---------------- Tokens

 // wuffs_base__token is an element of a byte stream's tokenization.
 //
 // See https://github.com/google/wuffs/blob/main/doc/note/tokens.md
 typedef struct wuffs_base__token__struct {
   uint64_t repr;

 #ifdef __cplusplus
   inline int64_t value() const;
   inline int64_t value_extension() const;
   inline int64_t value_major() const;
   inline int64_t value_base_category() const;
   inline uint64_t value_minor() const;
   inline uint64_t value_base_detail() const;
   inline int64_t value_base_detail__sign_extended() const;
   inline bool continued() const;
   inline uint64_t length() const;
 #endif  // __cplusplus

 } wuffs_base__token;

 static inline wuffs_base__token  //
 wuffs_base__make_token(uint64_t repr) {
   wuffs_base__token ret;
   ret.repr = repr;
   return ret;
 }

 // --------

 #define WUFFS_BASE__TOKEN__LENGTH__MAX_INCL 0xFFFF

 #define WUFFS_BASE__TOKEN__VALUE__SHIFT 17
 #define WUFFS_BASE__TOKEN__VALUE_EXTENSION__SHIFT 17
 #define WUFFS_BASE__TOKEN__VALUE_MAJOR__SHIFT 42
 #define WUFFS_BASE__TOKEN__VALUE_MINOR__SHIFT 17
 #define WUFFS_BASE__TOKEN__VALUE_BASE_CATEGORY__SHIFT 38
 #define WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT 17
 #define WUFFS_BASE__TOKEN__CONTINUED__SHIFT 16
 #define WUFFS_BASE__TOKEN__LENGTH__SHIFT 0

 #define WUFFS_BASE__TOKEN__VALUE_EXTENSION__NUM_BITS 46

 // --------

 #define WUFFS_BASE__TOKEN__VBC__FILLER 0
 #define WUFFS_BASE__TOKEN__VBC__STRUCTURE 1
 #define WUFFS_BASE__TOKEN__VBC__STRING 2
 #define WUFFS_BASE__TOKEN__VBC__UNICODE_CODE_POINT 3
 #define WUFFS_BASE__TOKEN__VBC__LITERAL 4
 #define WUFFS_BASE__TOKEN__VBC__NUMBER 5
 #define WUFFS_BASE__TOKEN__VBC__INLINE_INTEGER_SIGNED 6
 #define WUFFS_BASE__TOKEN__VBC__INLINE_INTEGER_UNSIGNED 7

 // --------

 #define WUFFS_BASE__TOKEN__VBD__FILLER__PUNCTUATION 0x00001
 #define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_BLOCK 0x00002
 #define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_LINE 0x00004

 // COMMENT_ANY is a bit-wise or of COMMENT_BLOCK AND COMMENT_LINE.
 #define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_ANY 0x00006

 // --------

 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__PUSH 0x00001
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__POP 0x00002
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_NONE 0x00010
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_LIST 0x00020
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_DICT 0x00040
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_NONE 0x01000
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_LIST 0x02000
 #define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_DICT 0x04000

 // --------

 // DEFINITELY_FOO means that the destination bytes (and also the source bytes,
 // for 1_DST_1_SRC_COPY) are in the FOO format. Definitely means that the lack
 // of the bit means "maybe FOO". It does not necessarily mean "not FOO".
 //
 // CHAIN_ETC means that decoding the entire token chain forms a UTF-8 or ASCII
 // string, not just this current token. CHAIN_ETC_UTF_8 therefore distinguishes
 // Unicode (UTF-8) strings from byte strings. MUST means that the the token
 // producer (e.g. parser) must verify this. SHOULD means that the token
 // consumer (e.g. renderer) should verify this.
 //
 // When a CHAIN_ETC_UTF_8 bit is set, the parser must ensure that non-ASCII
 // code points (with multi-byte UTF-8 encodings) do not straddle token
 // boundaries. Checking UTF-8 validity can inspect each token separately.
 //
 // The lack of any particular bit is conservative: it is valid for all-ASCII
 // strings, in a single- or multi-token chain, to have none of these bits set.
 #define WUFFS_BASE__TOKEN__VBD__STRING__DEFINITELY_UTF_8 0x00001
 #define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_MUST_BE_UTF_8 0x00002
 #define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_SHOULD_BE_UTF_8 0x00004
 #define WUFFS_BASE__TOKEN__VBD__STRING__DEFINITELY_ASCII 0x00010
 #define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_MUST_BE_ASCII 0x00020
 #define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_SHOULD_BE_ASCII 0x00040

 // CONVERT_D_DST_S_SRC means that multiples of S source bytes (possibly padded)
 // produces multiples of D destination bytes. For example,
 // CONVERT_1_DST_4_SRC_BACKSLASH_X means a source like "\\x23\\x67\\xAB", where
 // 12 src bytes encode 3 dst bytes.
 //
 // Post-processing may further transform those D destination bytes (e.g. treat
 // "\\xFF" as the Unicode code point U+00FF instead of the byte 0xFF), but that
 // is out of scope of this VBD's semantics.
 //
 // When src is the empty string, multiple conversion algorithms are applicable
 // (so these bits are not necessarily mutually exclusive), all producing the
 // same empty dst string.
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_0_DST_1_SRC_DROP 0x00100
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_1_SRC_COPY 0x00200
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_2_SRC_HEXADECIMAL 0x00400
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_4_SRC_BACKSLASH_X 0x00800
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_3_DST_4_SRC_BASE_64_STD 0x01000
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_3_DST_4_SRC_BASE_64_URL 0x02000
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_4_DST_5_SRC_ASCII_85 0x04000
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_5_DST_8_SRC_BASE_32_HEX 0x08000
 #define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_5_DST_8_SRC_BASE_32_STD 0x10000

 // --------

 #define WUFFS_BASE__TOKEN__VBD__LITERAL__UNDEFINED 0x00001
 #define WUFFS_BASE__TOKEN__VBD__LITERAL__NULL 0x00002
 #define WUFFS_BASE__TOKEN__VBD__LITERAL__FALSE 0x00004
 #define WUFFS_BASE__TOKEN__VBD__LITERAL__TRUE 0x00008

 // --------

 // For a source string of "123" or "0x9A", it is valid for a tokenizer to
 // return any combination of:
 //  - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_FLOATING_POINT.
 //  - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_SIGNED.
 //  - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_UNSIGNED.
 //
 // For a source string of "+123" or "-0x9A", only the first two are valid.
 //
 // For a source string of "123.", only the first one is valid.
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_FLOATING_POINT 0x00001
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_SIGNED 0x00002
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_UNSIGNED 0x00004

 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_NEG_INF 0x00010
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_POS_INF 0x00020
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_NEG_NAN 0x00040
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_POS_NAN 0x00080

 // The number 300 might be represented as "\x01\x2C", "\x2C\x01\x00\x00" or
 // "300", which are big-endian, little-endian or text. For binary formats, the
 // token length (after adjusting for FORMAT_IGNORE_ETC) discriminates
 // e.g. u16 little-endian vs u32 little-endian.
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_BINARY_BIG_ENDIAN 0x00100
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_BINARY_LITTLE_ENDIAN 0x00200
 #define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_TEXT 0x00400

 #define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_IGNORE_FIRST_BYTE 0x01000

 // --------

 // wuffs_base__token__value returns the token's high 46 bits, sign-extended. A
 // negative value means an extended token, non-negative means a simple token.
 static inline int64_t  //
 wuffs_base__token__value(const wuffs_base__token* t) {
   return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE__SHIFT;
 }

 // wuffs_base__token__value_extension returns a negative value if the token was
 // not an extended token.
 static inline int64_t  //
 wuffs_base__token__value_extension(const wuffs_base__token* t) {
   return (~(int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_EXTENSION__SHIFT;
 }

 // wuffs_base__token__value_major returns a negative value if the token was not
 // a simple token.
 static inline int64_t  //
 wuffs_base__token__value_major(const wuffs_base__token* t) {
   return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_MAJOR__SHIFT;
 }

 // wuffs_base__token__value_base_category returns a negative value if the token
 // was not a simple token.
 static inline int64_t  //
 wuffs_base__token__value_base_category(const wuffs_base__token* t) {
   return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_BASE_CATEGORY__SHIFT;
 }

 static inline uint64_t  //
 wuffs_base__token__value_minor(const wuffs_base__token* t) {
   return (t->repr >> WUFFS_BASE__TOKEN__VALUE_MINOR__SHIFT) & 0x1FFFFFF;
 }

 static inline uint64_t  //
 wuffs_base__token__value_base_detail(const wuffs_base__token* t) {
   return (t->repr >> WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT) & 0x1FFFFF;
 }

 static inline int64_t  //
 wuffs_base__token__value_base_detail__sign_extended(
     const wuffs_base__token* t) {
   // The VBD is 21 bits in the middle of t->repr. Left shift the high (64 - 21
   // - ETC__SHIFT) bits off, then right shift (sign-extending) back down.
   uint64_t u = t->repr << (43 - WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT);
   return ((int64_t)u) >> 43;
 }

 static inline bool  //
 wuffs_base__token__continued(const wuffs_base__token* t) {
   return t->repr & 0x10000;
 }

 static inline uint64_t  //
 wuffs_base__token__length(const wuffs_base__token* t) {
   return (t->repr >> WUFFS_BASE__TOKEN__LENGTH__SHIFT) & 0xFFFF;
 }

 #ifdef __cplusplus

 inline int64_t  //
 wuffs_base__token::value() const {
   return wuffs_base__token__value(this);
 }

 inline int64_t  //
 wuffs_base__token::value_extension() const {
   return wuffs_base__token__value_extension(this);
 }

 inline int64_t  //
 wuffs_base__token::value_major() const {
   return wuffs_base__token__value_major(this);
 }

 inline int64_t  //
 wuffs_base__token::value_base_category() const {
   return wuffs_base__token__value_base_category(this);
 }

 inline uint64_t  //
 wuffs_base__token::value_minor() const {
   return wuffs_base__token__value_minor(this);
 }

 inline uint64_t  //
 wuffs_base__token::value_base_detail() const {
   return wuffs_base__token__value_base_detail(this);
 }

 inline int64_t  //
 wuffs_base__token::value_base_detail__sign_extended() const {
   return wuffs_base__token__value_base_detail__sign_extended(this);
 }

 inline bool  //
 wuffs_base__token::continued() const {
   return wuffs_base__token__continued(this);
 }

 inline uint64_t  //
 wuffs_base__token::length() const {
   return wuffs_base__token__length(this);
 }

 #endif  // __cplusplus

 // --------

 typedef WUFFS_BASE__SLICE(wuffs_base__token) wuffs_base__slice_token;

 static inline wuffs_base__slice_token  //
 wuffs_base__make_slice_token(wuffs_base__token* ptr, size_t len) {
   wuffs_base__slice_token ret;
   ret.ptr = ptr;
   ret.len = len;
   return ret;
 }

 static inline wuffs_base__slice_token  //
 wuffs_base__empty_slice_token() {
   wuffs_base__slice_token ret;
   ret.ptr = NULL;
   ret.len = 0;
   return ret;
 }

 // --------

 // wuffs_base__token_buffer_meta is the metadata for a
 // wuffs_base__token_buffer's data.
 typedef struct wuffs_base__token_buffer_meta__struct {
   size_t wi;     // Write index. Invariant: wi <= len.
   size_t ri;     // Read  index. Invariant: ri <= wi.
   uint64_t pos;  // Position of the buffer start relative to the stream start.
   bool closed;   // No further writes are expected.
 } wuffs_base__token_buffer_meta;

 // wuffs_base__token_buffer is a 1-dimensional buffer (a pointer and length)
 // plus additional metadata.
 //
 // A value with all fields zero is a valid, empty buffer.
 typedef struct wuffs_base__token_buffer__struct {
   wuffs_base__slice_token data;
   wuffs_base__token_buffer_meta meta;

 #ifdef __cplusplus
   inline bool is_valid() const;
   inline void compact();
   inline uint64_t reader_length() const;
   inline wuffs_base__token* reader_pointer() const;
   inline wuffs_base__slice_token reader_slice() const;
   inline uint64_t reader_token_position() const;
   inline uint64_t writer_length() const;
   inline uint64_t writer_token_position() const;
   inline wuffs_base__token* writer_pointer() const;
   inline wuffs_base__slice_token writer_slice() const;
 #endif  // __cplusplus

 } wuffs_base__token_buffer;

 static inline wuffs_base__token_buffer  //
 wuffs_base__make_token_buffer(wuffs_base__slice_token data,
                               wuffs_base__token_buffer_meta meta) {
   wuffs_base__token_buffer ret;
   ret.data = data;
   ret.meta = meta;
   return ret;
 }

 static inline wuffs_base__token_buffer_meta  //
 wuffs_base__make_token_buffer_meta(size_t wi,
                                    size_t ri,
                                    uint64_t pos,
                                    bool closed) {
   wuffs_base__token_buffer_meta ret;
   ret.wi = wi;
   ret.ri = ri;
   ret.pos = pos;
   ret.closed = closed;
   return ret;
 }

 static inline wuffs_base__token_buffer  //
 wuffs_base__slice_token__reader(wuffs_base__slice_token s, bool closed) {
   wuffs_base__token_buffer ret;
   ret.data.ptr = s.ptr;
   ret.data.len = s.len;
   ret.meta.wi = s.len;
   ret.meta.ri = 0;
   ret.meta.pos = 0;
   ret.meta.closed = closed;
   return ret;
 }

 static inline wuffs_base__token_buffer  //
 wuffs_base__slice_token__writer(wuffs_base__slice_token s) {
   wuffs_base__token_buffer ret;
   ret.data.ptr = s.ptr;
   ret.data.len = s.len;
   ret.meta.wi = 0;
   ret.meta.ri = 0;
   ret.meta.pos = 0;
   ret.meta.closed = false;
   return ret;
 }

 static inline wuffs_base__token_buffer  //
 wuffs_base__empty_token_buffer() {
   wuffs_base__token_buffer ret;
   ret.data.ptr = NULL;
   ret.data.len = 0;
   ret.meta.wi = 0;
   ret.meta.ri = 0;
   ret.meta.pos = 0;
   ret.meta.closed = false;
   return ret;
 }

 static inline wuffs_base__token_buffer_meta  //
 wuffs_base__empty_token_buffer_meta() {
   wuffs_base__token_buffer_meta ret;
   ret.wi = 0;
   ret.ri = 0;
   ret.pos = 0;
   ret.closed = false;
   return ret;
 }

 static inline bool  //
 wuffs_base__token_buffer__is_valid(const wuffs_base__token_buffer* buf) {
   if (buf) {
     if (buf->data.ptr) {
       return (buf->meta.ri <= buf->meta.wi) && (buf->meta.wi <= buf->data.len);
     } else {
       return (buf->meta.ri == 0) && (buf->meta.wi == 0) && (buf->data.len == 0);
     }
   }
   return false;
 }

 // wuffs_base__token_buffer__compact moves any written but unread tokens to the
 // start of the buffer.
 static inline void  //
 wuffs_base__token_buffer__compact(wuffs_base__token_buffer* buf) {
   if (!buf || (buf->meta.ri == 0)) {
     return;
   }
   buf->meta.pos = wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.ri);
   size_t n = buf->meta.wi - buf->meta.ri;
   if (n != 0) {
     memmove(buf->data.ptr, buf->data.ptr + buf->meta.ri,
             n * sizeof(wuffs_base__token));
   }
   buf->meta.wi = n;
   buf->meta.ri = 0;
 }

 static inline uint64_t  //
 wuffs_base__token_buffer__reader_length(const wuffs_base__token_buffer* buf) {
   return buf ? buf->meta.wi - buf->meta.ri : 0;
 }

 static inline wuffs_base__token*  //
 wuffs_base__token_buffer__reader_pointer(const wuffs_base__token_buffer* buf) {
   return buf ? (buf->data.ptr + buf->meta.ri) : NULL;
 }

 static inline wuffs_base__slice_token  //
 wuffs_base__token_buffer__reader_slice(const wuffs_base__token_buffer* buf) {
   return buf ? wuffs_base__make_slice_token(buf->data.ptr + buf->meta.ri,
                                             buf->meta.wi - buf->meta.ri)
              : wuffs_base__empty_slice_token();
 }

 static inline uint64_t  //
 wuffs_base__token_buffer__reader_token_position(
     const wuffs_base__token_buffer* buf) {
   return buf ? wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.ri) : 0;
 }

 static inline uint64_t  //
 wuffs_base__token_buffer__writer_length(const wuffs_base__token_buffer* buf) {
   return buf ? buf->data.len - buf->meta.wi : 0;
 }

 static inline wuffs_base__token*  //
 wuffs_base__token_buffer__writer_pointer(const wuffs_base__token_buffer* buf) {
   return buf ? (buf->data.ptr + buf->meta.wi) : NULL;
 }

 static inline wuffs_base__slice_token  //
 wuffs_base__token_buffer__writer_slice(const wuffs_base__token_buffer* buf) {
   return buf ? wuffs_base__make_slice_token(buf->data.ptr + buf->meta.wi,
                                             buf->data.len - buf->meta.wi)
              : wuffs_base__empty_slice_token();
 }

 static inline uint64_t  //
 wuffs_base__token_buffer__writer_token_position(
     const wuffs_base__token_buffer* buf) {
   return buf ? wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.wi) : 0;
 }

 #ifdef __cplusplus

 inline bool  //
 wuffs_base__token_buffer::is_valid() const {
   return wuffs_base__token_buffer__is_valid(this);
 }

 inline void  //
 wuffs_base__token_buffer::compact() {
   wuffs_base__token_buffer__compact(this);
 }

 inline uint64_t  //
 wuffs_base__token_buffer::reader_length() const {
   return wuffs_base__token_buffer__reader_length(this);
 }

 inline wuffs_base__token*  //
 wuffs_base__token_buffer::reader_pointer() const {
   return wuffs_base__token_buffer__reader_pointer(this);
 }

 inline wuffs_base__slice_token  //
 wuffs_base__token_buffer::reader_slice() const {
   return wuffs_base__token_buffer__reader_slice(this);
 }

 inline uint64_t  //
 wuffs_base__token_buffer::reader_token_position() const {
   return wuffs_base__token_buffer__reader_token_position(this);
 }

 inline uint64_t  //
 wuffs_base__token_buffer::writer_length() const {
   return wuffs_base__token_buffer__writer_length(this);
 }

 inline wuffs_base__token*  //
 wuffs_base__token_buffer::writer_pointer() const {
   return wuffs_base__token_buffer__writer_pointer(this);
 }

 inline wuffs_base__slice_token  //
 wuffs_base__token_buffer::writer_slice() const {
   return wuffs_base__token_buffer__writer_slice(this);
 }

 inline uint64_t  //
 wuffs_base__token_buffer::writer_token_position() const {
   return wuffs_base__token_buffer__writer_token_position(this);
 }

 #endif  // __cplusplus
	// Copyright 2020 The Wuffs Authors.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// https://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	// ---------------- Tokens

	// wuffs_base__token is an element of a byte stream's tokenization.
	//
	// See https://github.com/google/wuffs/blob/main/doc/note/tokens.md
	typedef struct wuffs_base__token__struct {
	uint64_t repr;

	#ifdef __cplusplus
	inline int64_t value() const;
	inline int64_t value_extension() const;
	inline int64_t value_major() const;
	inline int64_t value_base_category() const;
	inline uint64_t value_minor() const;
	inline uint64_t value_base_detail() const;
	inline int64_t value_base_detail__sign_extended() const;
	inline bool continued() const;
	inline uint64_t length() const;
	#endif // __cplusplus

	} wuffs_base__token;

	static inline wuffs_base__token //
	wuffs_base__make_token(uint64_t repr) {
	wuffs_base__token ret;
	ret.repr = repr;
	return ret;
	}

	// --------

	#define WUFFS_BASE__TOKEN__LENGTH__MAX_INCL 0xFFFF

	#define WUFFS_BASE__TOKEN__VALUE__SHIFT 17
	#define WUFFS_BASE__TOKEN__VALUE_EXTENSION__SHIFT 17
	#define WUFFS_BASE__TOKEN__VALUE_MAJOR__SHIFT 42
	#define WUFFS_BASE__TOKEN__VALUE_MINOR__SHIFT 17
	#define WUFFS_BASE__TOKEN__VALUE_BASE_CATEGORY__SHIFT 38
	#define WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT 17
	#define WUFFS_BASE__TOKEN__CONTINUED__SHIFT 16
	#define WUFFS_BASE__TOKEN__LENGTH__SHIFT 0

	#define WUFFS_BASE__TOKEN__VALUE_EXTENSION__NUM_BITS 46

	// --------

	#define WUFFS_BASE__TOKEN__VBC__FILLER 0
	#define WUFFS_BASE__TOKEN__VBC__STRUCTURE 1
	#define WUFFS_BASE__TOKEN__VBC__STRING 2
	#define WUFFS_BASE__TOKEN__VBC__UNICODE_CODE_POINT 3
	#define WUFFS_BASE__TOKEN__VBC__LITERAL 4
	#define WUFFS_BASE__TOKEN__VBC__NUMBER 5
	#define WUFFS_BASE__TOKEN__VBC__INLINE_INTEGER_SIGNED 6
	#define WUFFS_BASE__TOKEN__VBC__INLINE_INTEGER_UNSIGNED 7

	// --------

	#define WUFFS_BASE__TOKEN__VBD__FILLER__PUNCTUATION 0x00001
	#define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_BLOCK 0x00002
	#define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_LINE 0x00004

	// COMMENT_ANY is a bit-wise or of COMMENT_BLOCK AND COMMENT_LINE.
	#define WUFFS_BASE__TOKEN__VBD__FILLER__COMMENT_ANY 0x00006

	// --------

	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__PUSH 0x00001
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__POP 0x00002
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_NONE 0x00010
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_LIST 0x00020
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__FROM_DICT 0x00040
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_NONE 0x01000
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_LIST 0x02000
	#define WUFFS_BASE__TOKEN__VBD__STRUCTURE__TO_DICT 0x04000

	// --------

	// DEFINITELY_FOO means that the destination bytes (and also the source bytes,
	// for 1_DST_1_SRC_COPY) are in the FOO format. Definitely means that the lack
	// of the bit means "maybe FOO". It does not necessarily mean "not FOO".
	//
	// CHAIN_ETC means that decoding the entire token chain forms a UTF-8 or ASCII
	// string, not just this current token. CHAIN_ETC_UTF_8 therefore distinguishes
	// Unicode (UTF-8) strings from byte strings. MUST means that the the token
	// producer (e.g. parser) must verify this. SHOULD means that the token
	// consumer (e.g. renderer) should verify this.
	//
	// When a CHAIN_ETC_UTF_8 bit is set, the parser must ensure that non-ASCII
	// code points (with multi-byte UTF-8 encodings) do not straddle token
	// boundaries. Checking UTF-8 validity can inspect each token separately.
	//
	// The lack of any particular bit is conservative: it is valid for all-ASCII
	// strings, in a single- or multi-token chain, to have none of these bits set.
	#define WUFFS_BASE__TOKEN__VBD__STRING__DEFINITELY_UTF_8 0x00001
	#define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_MUST_BE_UTF_8 0x00002
	#define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_SHOULD_BE_UTF_8 0x00004
	#define WUFFS_BASE__TOKEN__VBD__STRING__DEFINITELY_ASCII 0x00010
	#define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_MUST_BE_ASCII 0x00020
	#define WUFFS_BASE__TOKEN__VBD__STRING__CHAIN_SHOULD_BE_ASCII 0x00040

	// CONVERT_D_DST_S_SRC means that multiples of S source bytes (possibly padded)
	// produces multiples of D destination bytes. For example,
	// CONVERT_1_DST_4_SRC_BACKSLASH_X means a source like "\\x23\\x67\\xAB", where
	// 12 src bytes encode 3 dst bytes.
	//
	// Post-processing may further transform those D destination bytes (e.g. treat
	// "\\xFF" as the Unicode code point U+00FF instead of the byte 0xFF), but that
	// is out of scope of this VBD's semantics.
	//
	// When src is the empty string, multiple conversion algorithms are applicable
	// (so these bits are not necessarily mutually exclusive), all producing the
	// same empty dst string.
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_0_DST_1_SRC_DROP 0x00100
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_1_SRC_COPY 0x00200
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_2_SRC_HEXADECIMAL 0x00400
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_1_DST_4_SRC_BACKSLASH_X 0x00800
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_3_DST_4_SRC_BASE_64_STD 0x01000
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_3_DST_4_SRC_BASE_64_URL 0x02000
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_4_DST_5_SRC_ASCII_85 0x04000
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_5_DST_8_SRC_BASE_32_HEX 0x08000
	#define WUFFS_BASE__TOKEN__VBD__STRING__CONVERT_5_DST_8_SRC_BASE_32_STD 0x10000

	// --------

	#define WUFFS_BASE__TOKEN__VBD__LITERAL__UNDEFINED 0x00001
	#define WUFFS_BASE__TOKEN__VBD__LITERAL__NULL 0x00002
	#define WUFFS_BASE__TOKEN__VBD__LITERAL__FALSE 0x00004
	#define WUFFS_BASE__TOKEN__VBD__LITERAL__TRUE 0x00008

	// --------

	// For a source string of "123" or "0x9A", it is valid for a tokenizer to
	// return any combination of:
	// - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_FLOATING_POINT.
	// - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_SIGNED.
	// - WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_UNSIGNED.
	//
	// For a source string of "+123" or "-0x9A", only the first two are valid.
	//
	// For a source string of "123.", only the first one is valid.
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_FLOATING_POINT 0x00001
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_SIGNED 0x00002
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_INTEGER_UNSIGNED 0x00004

	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_NEG_INF 0x00010
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_POS_INF 0x00020
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_NEG_NAN 0x00040
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__CONTENT_POS_NAN 0x00080

	// The number 300 might be represented as "\x01\x2C", "\x2C\x01\x00\x00" or
	// "300", which are big-endian, little-endian or text. For binary formats, the
	// token length (after adjusting for FORMAT_IGNORE_ETC) discriminates
	// e.g. u16 little-endian vs u32 little-endian.
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_BINARY_BIG_ENDIAN 0x00100
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_BINARY_LITTLE_ENDIAN 0x00200
	#define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_TEXT 0x00400

	#define WUFFS_BASE__TOKEN__VBD__NUMBER__FORMAT_IGNORE_FIRST_BYTE 0x01000

	// --------

	// wuffs_base__token__value returns the token's high 46 bits, sign-extended. A
	// negative value means an extended token, non-negative means a simple token.
	static inline int64_t //
	wuffs_base__token__value(const wuffs_base__token* t) {
	return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE__SHIFT;
	}

	// wuffs_base__token__value_extension returns a negative value if the token was
	// not an extended token.
	static inline int64_t //
	wuffs_base__token__value_extension(const wuffs_base__token* t) {
	return (~(int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_EXTENSION__SHIFT;
	}

	// wuffs_base__token__value_major returns a negative value if the token was not
	// a simple token.
	static inline int64_t //
	wuffs_base__token__value_major(const wuffs_base__token* t) {
	return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_MAJOR__SHIFT;
	}

	// wuffs_base__token__value_base_category returns a negative value if the token
	// was not a simple token.
	static inline int64_t //
	wuffs_base__token__value_base_category(const wuffs_base__token* t) {
	return ((int64_t)(t->repr)) >> WUFFS_BASE__TOKEN__VALUE_BASE_CATEGORY__SHIFT;
	}

	static inline uint64_t //
	wuffs_base__token__value_minor(const wuffs_base__token* t) {
	return (t->repr >> WUFFS_BASE__TOKEN__VALUE_MINOR__SHIFT) & 0x1FFFFFF;
	}

	static inline uint64_t //
	wuffs_base__token__value_base_detail(const wuffs_base__token* t) {
	return (t->repr >> WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT) & 0x1FFFFF;
	}

	static inline int64_t //
	wuffs_base__token__value_base_detail__sign_extended(
	const wuffs_base__token* t) {
	// The VBD is 21 bits in the middle of t->repr. Left shift the high (64 - 21
	// - ETC__SHIFT) bits off, then right shift (sign-extending) back down.
	uint64_t u = t->repr << (43 - WUFFS_BASE__TOKEN__VALUE_BASE_DETAIL__SHIFT);
	return ((int64_t)u) >> 43;
	}

	static inline bool //
	wuffs_base__token__continued(const wuffs_base__token* t) {
	return t->repr & 0x10000;
	}

	static inline uint64_t //
	wuffs_base__token__length(const wuffs_base__token* t) {
	return (t->repr >> WUFFS_BASE__TOKEN__LENGTH__SHIFT) & 0xFFFF;
	}

	#ifdef __cplusplus

	inline int64_t //
	wuffs_base__token::value() const {
	return wuffs_base__token__value(this);
	}

	inline int64_t //
	wuffs_base__token::value_extension() const {
	return wuffs_base__token__value_extension(this);
	}

	inline int64_t //
	wuffs_base__token::value_major() const {
	return wuffs_base__token__value_major(this);
	}

	inline int64_t //
	wuffs_base__token::value_base_category() const {
	return wuffs_base__token__value_base_category(this);
	}

	inline uint64_t //
	wuffs_base__token::value_minor() const {
	return wuffs_base__token__value_minor(this);
	}

	inline uint64_t //
	wuffs_base__token::value_base_detail() const {
	return wuffs_base__token__value_base_detail(this);
	}

	inline int64_t //
	wuffs_base__token::value_base_detail__sign_extended() const {
	return wuffs_base__token__value_base_detail__sign_extended(this);
	}

	inline bool //
	wuffs_base__token::continued() const {
	return wuffs_base__token__continued(this);
	}

	inline uint64_t //
	wuffs_base__token::length() const {
	return wuffs_base__token__length(this);
	}

	#endif // __cplusplus

	// --------

	typedef WUFFS_BASE__SLICE(wuffs_base__token) wuffs_base__slice_token;

	static inline wuffs_base__slice_token //
	wuffs_base__make_slice_token(wuffs_base__token* ptr, size_t len) {
	wuffs_base__slice_token ret;
	ret.ptr = ptr;
	ret.len = len;
	return ret;
	}

	static inline wuffs_base__slice_token //
	wuffs_base__empty_slice_token() {
	wuffs_base__slice_token ret;
	ret.ptr = NULL;
	ret.len = 0;
	return ret;
	}

	// --------

	// wuffs_base__token_buffer_meta is the metadata for a
	// wuffs_base__token_buffer's data.
	typedef struct wuffs_base__token_buffer_meta__struct {
	size_t wi; // Write index. Invariant: wi <= len.
	size_t ri; // Read index. Invariant: ri <= wi.
	uint64_t pos; // Position of the buffer start relative to the stream start.
	bool closed; // No further writes are expected.
	} wuffs_base__token_buffer_meta;

	// wuffs_base__token_buffer is a 1-dimensional buffer (a pointer and length)
	// plus additional metadata.
	//
	// A value with all fields zero is a valid, empty buffer.
	typedef struct wuffs_base__token_buffer__struct {
	wuffs_base__slice_token data;
	wuffs_base__token_buffer_meta meta;

	#ifdef __cplusplus
	inline bool is_valid() const;
	inline void compact();
	inline uint64_t reader_length() const;
	inline wuffs_base__token* reader_pointer() const;
	inline wuffs_base__slice_token reader_slice() const;
	inline uint64_t reader_token_position() const;
	inline uint64_t writer_length() const;
	inline uint64_t writer_token_position() const;
	inline wuffs_base__token* writer_pointer() const;
	inline wuffs_base__slice_token writer_slice() const;
	#endif // __cplusplus

	} wuffs_base__token_buffer;

	static inline wuffs_base__token_buffer //
	wuffs_base__make_token_buffer(wuffs_base__slice_token data,
	wuffs_base__token_buffer_meta meta) {
	wuffs_base__token_buffer ret;
	ret.data = data;
	ret.meta = meta;
	return ret;
	}

	static inline wuffs_base__token_buffer_meta //
	wuffs_base__make_token_buffer_meta(size_t wi,
	size_t ri,
	uint64_t pos,
	bool closed) {
	wuffs_base__token_buffer_meta ret;
	ret.wi = wi;
	ret.ri = ri;
	ret.pos = pos;
	ret.closed = closed;
	return ret;
	}

	static inline wuffs_base__token_buffer //
	wuffs_base__slice_token__reader(wuffs_base__slice_token s, bool closed) {
	wuffs_base__token_buffer ret;
	ret.data.ptr = s.ptr;
	ret.data.len = s.len;
	ret.meta.wi = s.len;
	ret.meta.ri = 0;
	ret.meta.pos = 0;
	ret.meta.closed = closed;
	return ret;
	}

	static inline wuffs_base__token_buffer //
	wuffs_base__slice_token__writer(wuffs_base__slice_token s) {
	wuffs_base__token_buffer ret;
	ret.data.ptr = s.ptr;
	ret.data.len = s.len;
	ret.meta.wi = 0;
	ret.meta.ri = 0;
	ret.meta.pos = 0;
	ret.meta.closed = false;
	return ret;
	}

	static inline wuffs_base__token_buffer //
	wuffs_base__empty_token_buffer() {
	wuffs_base__token_buffer ret;
	ret.data.ptr = NULL;
	ret.data.len = 0;
	ret.meta.wi = 0;
	ret.meta.ri = 0;
	ret.meta.pos = 0;
	ret.meta.closed = false;
	return ret;
	}

	static inline wuffs_base__token_buffer_meta //
	wuffs_base__empty_token_buffer_meta() {
	wuffs_base__token_buffer_meta ret;
	ret.wi = 0;
	ret.ri = 0;
	ret.pos = 0;
	ret.closed = false;
	return ret;
	}

	static inline bool //
	wuffs_base__token_buffer__is_valid(const wuffs_base__token_buffer* buf) {
	if (buf) {
	if (buf->data.ptr) {
	return (buf->meta.ri <= buf->meta.wi) && (buf->meta.wi <= buf->data.len);
	} else {
	return (buf->meta.ri == 0) && (buf->meta.wi == 0) && (buf->data.len == 0);
	}
	}
	return false;
	}

	// wuffs_base__token_buffer__compact moves any written but unread tokens to the
	// start of the buffer.
	static inline void //
	wuffs_base__token_buffer__compact(wuffs_base__token_buffer* buf) {
	if (!buf \|\| (buf->meta.ri == 0)) {
	return;
	}
	buf->meta.pos = wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.ri);
	size_t n = buf->meta.wi - buf->meta.ri;
	if (n != 0) {
	memmove(buf->data.ptr, buf->data.ptr + buf->meta.ri,
	n * sizeof(wuffs_base__token));
	}
	buf->meta.wi = n;
	buf->meta.ri = 0;
	}

	static inline uint64_t //
	wuffs_base__token_buffer__reader_length(const wuffs_base__token_buffer* buf) {
	return buf ? buf->meta.wi - buf->meta.ri : 0;
	}

	static inline wuffs_base__token* //
	wuffs_base__token_buffer__reader_pointer(const wuffs_base__token_buffer* buf) {
	return buf ? (buf->data.ptr + buf->meta.ri) : NULL;
	}

	static inline wuffs_base__slice_token //
	wuffs_base__token_buffer__reader_slice(const wuffs_base__token_buffer* buf) {
	return buf ? wuffs_base__make_slice_token(buf->data.ptr + buf->meta.ri,
	buf->meta.wi - buf->meta.ri)
	: wuffs_base__empty_slice_token();
	}

	static inline uint64_t //
	wuffs_base__token_buffer__reader_token_position(
	const wuffs_base__token_buffer* buf) {
	return buf ? wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.ri) : 0;
	}

	static inline uint64_t //
	wuffs_base__token_buffer__writer_length(const wuffs_base__token_buffer* buf) {
	return buf ? buf->data.len - buf->meta.wi : 0;
	}

	static inline wuffs_base__token* //
	wuffs_base__token_buffer__writer_pointer(const wuffs_base__token_buffer* buf) {
	return buf ? (buf->data.ptr + buf->meta.wi) : NULL;
	}

	static inline wuffs_base__slice_token //
	wuffs_base__token_buffer__writer_slice(const wuffs_base__token_buffer* buf) {
	return buf ? wuffs_base__make_slice_token(buf->data.ptr + buf->meta.wi,
	buf->data.len - buf->meta.wi)
	: wuffs_base__empty_slice_token();
	}

	static inline uint64_t //
	wuffs_base__token_buffer__writer_token_position(
	const wuffs_base__token_buffer* buf) {
	return buf ? wuffs_base__u64__sat_add(buf->meta.pos, buf->meta.wi) : 0;
	}

	#ifdef __cplusplus

	inline bool //
	wuffs_base__token_buffer::is_valid() const {
	return wuffs_base__token_buffer__is_valid(this);
	}

	inline void //
	wuffs_base__token_buffer::compact() {
	wuffs_base__token_buffer__compact(this);
	}

	inline uint64_t //
	wuffs_base__token_buffer::reader_length() const {
	return wuffs_base__token_buffer__reader_length(this);
	}

	inline wuffs_base__token* //
	wuffs_base__token_buffer::reader_pointer() const {
	return wuffs_base__token_buffer__reader_pointer(this);
	}

	inline wuffs_base__slice_token //
	wuffs_base__token_buffer::reader_slice() const {
	return wuffs_base__token_buffer__reader_slice(this);
	}

	inline uint64_t //
	wuffs_base__token_buffer::reader_token_position() const {
	return wuffs_base__token_buffer__reader_token_position(this);
	}

	inline uint64_t //
	wuffs_base__token_buffer::writer_length() const {
	return wuffs_base__token_buffer__writer_length(this);
	}

	inline wuffs_base__token* //
	wuffs_base__token_buffer::writer_pointer() const {
	return wuffs_base__token_buffer__writer_pointer(this);
	}

	inline wuffs_base__slice_token //
	wuffs_base__token_buffer::writer_slice() const {
	return wuffs_base__token_buffer__writer_slice(this);
	}

	inline uint64_t //
	wuffs_base__token_buffer::writer_token_position() const {
	return wuffs_base__token_buffer__writer_token_position(this);
	}

	#endif // __cplusplus