8.2.4. Tokenization

Implementations must act as if they used the following state machine to tokenize HTML. The state machine must start in the data state. Most states consume a single character, which may have various side-effects, and either switches the state machine to a new state to reconsume the same character, or switches it to a new state to consume the next character, or stays in the same state to consume the next character. Some states have more complicated behavior and can consume several characters before switching to another state. In some cases, the tokenizer state is also changed by the tree construction stage.

The exact behavior of certain states depends on the insertion mode and the stack of open elements. Certain states also use a temporary buffer to track progress.

The output of the tokenization step is a series of zero or more of the following tokens: DOCTYPE, start tag, end tag, comment, character, end-of-file. DOCTYPE tokens have a name, a public identifier, a system identifier, and a force-quirks flag. When a DOCTYPE token is created, its name, public identifier, and system identifier must be marked as missing (which is a distinct state from the empty string), and the force-quirks flag must be set to off (its other state is on). Start and end tag tokens have a tag name, a self-closing flag, and a list of attributes, each of which has a name and a value. When a start or end tag token is created, its self-closing flag must be unset (its other state is that it be set), and its attributes list must be empty. Comment and character tokens have data.

When a token is emitted, it must immediately be handled by the tree construction stage. The tree construction stage can affect the state of the tokenization stage, and can insert additional characters into the stream. (For example, the script element can result in scripts executing and using the dynamic markup insertion APIs to insert characters into the stream being tokenized.)

When a start tag token is emitted with its self-closing flag set, if the flag is not acknowledged when it is processed by the tree construction stage, that is a parse error.

When an end tag token is emitted with attributes, that is a parse error.

When an end tag token is emitted with its self-closing flag set, that is a parse error.

An appropriate end tag token is an end tag token whose tag name matches the tag name of the last start tag to have been emitted from this tokenizer, if any. If no start tag has been emitted from this tokenizer, then no end tag token is appropriate.

Before each step of the tokenizer, the user agent must first check the parser pause flag. If it is true, then the tokenizer must abort the processing of any nested invocations of the tokenizer, yielding control back to the caller.

The tokenizer state machine consists of the states defined in the following subsections.

8.2.4.1 Data state

Consume the next input character:

U+0026 AMPERSAND (&)

Switch to the character reference in data state.

U+003C LESS-THAN SIGN (<)

Switch to the tag open state.

U+0000 NULL

Parse error. Emit the current input character as a character token.

EOF

Emit an end-of-file token.

Anything else

Emit the current input character as a character token.

8.2.4.2 Character reference in data state

Switch to the data state.

Attempt to consume a character reference, with no additional allowed character.

If nothing is returned, emit a U+0026 AMPERSAND character (&) token.

Otherwise, emit the character tokens that were returned.

8.2.4.3 RCDATA state

Consume the next input character:

U+0026 AMPERSAND (&)

Switch to the character reference in RCDATA state.

U+003C LESS-THAN SIGN (<)

Switch to the RCDATA less-than sign state.

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Emit an end-of-file token.

Anything else

Emit the current input character as a character token.

8.2.4.4 Character reference in RCDATA state

Switch to the RCDATA state.

Attempt to consume a character reference, with no additional allowed character.

If nothing is returned, emit a U+0026 AMPERSAND character (&) token.

Otherwise, emit the character tokens that were returned.

8.2.4.5 RAWTEXT state

Consume the next input character:

U+003C LESS-THAN SIGN (<)

Switch to the RAWTEXT less-than sign state.

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Emit an end-of-file token.

Anything else

Emit the current input character as a character token.

8.2.4.6 Script data state

Consume the next input character:

U+003C LESS-THAN SIGN (<)

Switch to the script data less-than sign state.

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Emit an end-of-file token.

Anything else

Emit the current input character as a character token.

8.2.4.7 PLAINTEXT state

Consume the next input character:

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Emit an end-of-file token.

Anything else

Emit the current input character as a character token.

8.2.4.8 Tag open state

Consume the next input character:

"!" (U+0021)

Switch to the markup declaration open state.

"/" (U+002F)

Switch to the end tag open state.

Uppercase ASCII letter

Create a new start tag token, set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point), then switch to the tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new start tag token, set its tag name to the current input character, then switch to the tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

"?" (U+003F)

Parse error. Switch to the bogus comment state.

Anything else

Parse error. Switch to the data state. Emit a U+003C LESS-THAN SIGN character token. Reconsume the current input character.

8.2.4.9 End tag open state

Consume the next input character:

Uppercase ASCII letter

Create a new end tag token, set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point), then switch to the tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new end tag token, set its tag name to the current input character, then switch to the tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

U+003E GREATER-THAN SIGN (>)

Parse error. Switch to the data state.

EOF

Parse error. Switch to the data state. Emit a U+003C LESS-THAN SIGN character token and a U+002F SOLIDUS character token. Reconsume the EOF character.

Anything else

Parse error. Switch to the bogus comment state.

8.2.4.10 Tag name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Switch to the before attribute name state.

"/" (U+002F)

Switch to the self-closing start tag state.

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current tag token's tag name.

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current tag token's tag name.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current tag token's tag name.

8.2.4.11 RCDATA less-than sign state

Consume the next input character:

"/" (U+002F)

Set the temporary buffer to the empty string. Switch to the RCDATA end tag open state.

Anything else

Switch to the RCDATA state. Emit a U+003C LESS-THAN SIGN character token. Reconsume the current input character.

8.2.4.12 RCDATA end tag open state

Consume the next input character:

Uppercase ASCII letter

Create a new end tag token, and set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point). Append the current input character to the temporary buffer. Finally, switch to the RCDATA end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new end tag token, and set its tag name to the current input character. Append the current input character to the temporary buffer. Finally, switch to the RCDATA end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Anything else

Switch to the RCDATA state. Emit a U+003C LESS-THAN SIGN character token and a U+002F SOLIDUS character token. Reconsume the current input character.

8.2.4.13 RCDATA end tag name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

If the current end tag token is an appropriate end tag token, then switch to the before attribute name state. Otherwise, treat it as per the "anything else" entry below.

"/" (U+002F)

If the current end tag token is an appropriate end tag token, then switch to the self-closing start tag state. Otherwise, treat it as per the "anything else" entry below.

U+003E GREATER-THAN SIGN (>)

If the current end tag token is an appropriate end tag token, then switch to the data state and emit the current tag token. Otherwise, treat it as per the "anything else" entry below.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current tag token's tag name. Append the current input character to the temporary buffer.

Lowercase ASCII letter

Append the current input character to the current tag token's tag name. Append the current input character to the temporary buffer.

Anything else

Switch to the RCDATA state. Emit a U+003C LESS-THAN SIGN character token, a U+002F SOLIDUS character token, and a character token for each of the characters in the temporary buffer (in the order they were added to the buffer). Reconsume the current input character.

8.2.4.14 RAWTEXT less-than sign state

Consume the next input character:

"/" (U+002F)

Set the temporary buffer to the empty string. Switch to the RAWTEXT end tag open state.

Anything else

Switch to the RAWTEXT state. Emit a U+003C LESS-THAN SIGN character token. Reconsume the current input character.

8.2.4.15 RAWTEXT end tag open state

Consume the next input character:

Uppercase ASCII letter

Create a new end tag token, and set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point). Append the current input character to the temporary buffer. Finally, switch to the RAWTEXT end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new end tag token, and set its tag name to the current input character. Append the current input character to the temporary buffer. Finally, switch to the RAWTEXT end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Anything else

Switch to the RAWTEXT state. Emit a U+003C LESS-THAN SIGN character token and a U+002F SOLIDUS character token. Reconsume the current input character.

8.2.4.16 RAWTEXT end tag name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

If the current end tag token is an appropriate end tag token, then switch to the before attribute name state. Otherwise, treat it as per the "anything else" entry below.

"/" (U+002F)

If the current end tag token is an appropriate end tag token, then switch to the self-closing start tag state. Otherwise, treat it as per the "anything else" entry below.

U+003E GREATER-THAN SIGN (>)

If the current end tag token is an appropriate end tag token, then switch to the data state and emit the current tag token. Otherwise, treat it as per the "anything else" entry below.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current tag token's tag name. Append the current input character to the temporary buffer.

Lowercase ASCII letter

Append the current input character to the current tag token's tag name. Append the current input character to the temporary buffer.

Anything else

Switch to the RAWTEXT state. Emit a U+003C LESS-THAN SIGN character token, a U+002F SOLIDUS character token, and a character token for each of the characters in the temporary buffer (in the order they were added to the buffer). Reconsume the current input character.

8.2.4.17 Script data less-than sign state

Consume the next input character:

"/" (U+002F)

Set the temporary buffer to the empty string. Switch to the script data end tag open state.

"!" (U+0021)

Switch to the script data escape start state. Emit a U+003C LESS-THAN SIGN character token and a U+0021 EXCLAMATION MARK character token.

Anything else

Switch to the script data state. Emit a U+003C LESS-THAN SIGN character token. Reconsume the current input character.

8.2.4.18 Script data end tag open state

Consume the next input character:

Uppercase ASCII letter

Create a new end tag token, and set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point). Append the current input character to the temporary buffer. Finally, switch to the script data end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new end tag token, and set its tag name to the current input character. Append the current input character to the temporary buffer. Finally, switch to the script data end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Anything else

Switch to the script data state. Emit a U+003C LESS-THAN SIGN character token and a U+002F SOLIDUS character token. Reconsume the current input character.

8.2.4.19 Script data end tag name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

If the current end tag token is an appropriate end tag token, then switch to the before attribute name state. Otherwise, treat it as per the "anything else" entry below.

"/" (U+002F)

If the current end tag token is an appropriate end tag token, then switch to the self-closing start tag state. Otherwise, treat it as per the "anything else" entry below.

U+003E GREATER-THAN SIGN (>)

If the current end tag token is an appropriate end tag token, then switch to the data state and emit the current tag token. Otherwise, treat it as per the "anything else" entry below.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current tag token's tag name. Append the current input character to the temporary buffer.

Lowercase ASCII letter

Append the current input character to the current tag token's tag name. Append the current input character to the temporary buffer.

Anything else

Switch to the script data state. Emit a U+003C LESS-THAN SIGN character token, a U+002F SOLIDUS character token, and a character token for each of the characters in the temporary buffer (in the order they were added to the buffer). Reconsume the current input character.

8.2.4.20 Script data escape start state

Consume the next input character:

"-" (U+002D)

Switch to the script data escape start dash state. Emit a U+002D HYPHEN-MINUS character token.

Anything else

Switch to the script data state. Reconsume the current input character.

8.2.4.21 Script data escape start dash state

Consume the next input character:

"-" (U+002D)

Switch to the script data escaped dash dash state. Emit a U+002D HYPHEN-MINUS character token.

Anything else

Switch to the script data state. Reconsume the current input character.

8.2.4.22 Script data escaped state

Consume the next input character:

"-" (U+002D)

Switch to the script data escaped dash state. Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data escaped less-than sign state.

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Switch to the data state. Parse error. Reconsume the EOF character.

Anything else

Emit the current input character as a character token.

8.2.4.23 Script data escaped dash state

Consume the next input character:

"-" (U+002D)

Switch to the script data escaped dash dash state. Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data escaped less-than sign state.

U+0000 NULL

Parse error. Switch to the script data escaped state. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Switch to the script data escaped state. Emit the current input character as a character token.

8.2.4.24 Script data escaped dash dash state

Consume the next input character:

"-" (U+002D)

Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data escaped less-than sign state.

U+003E GREATER-THAN SIGN (>)

Switch to the script data state. Emit a U+003E GREATER-THAN SIGN character token.

U+0000 NULL

Parse error. Switch to the script data escaped state. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Switch to the script data escaped state. Emit the current input character as a character token.

8.2.4.25 Script data escaped less-than sign state

Consume the next input character:

"/" (U+002F)

Set the temporary buffer to the empty string. Switch to the script data escaped end tag open state.

Uppercase ASCII letter

Set the temporary buffer to the empty string. Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the temporary buffer. Switch to the script data double escape start state. Emit a U+003C LESS-THAN SIGN character token and the current input character as a character token.

Lowercase ASCII letter

Set the temporary buffer to the empty string. Append the current input character to the temporary buffer. Switch to the script data double escape start state. Emit a U+003C LESS-THAN SIGN character token and the current input character as a character token.

Anything else

Switch to the script data escaped state. Emit a U+003C LESS-THAN SIGN character token. Reconsume the current input character.

8.2.4.26 Script data escaped end tag open state

Consume the next input character:

Uppercase ASCII letter

Create a new end tag token, and set its tag name to the lowercase version of the current input character (add 0x0020 to the character's code point). Append the current input character to the temporary buffer. Finally, switch to the script data escaped end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Lowercase ASCII letter

Create a new end tag token, and set its tag name to the current input character. Append the current input character to the temporary buffer. Finally, switch to the script data escaped end tag name state. (Don't emit the token yet; further details will be filled in before it is emitted.)

Anything else

Switch to the script data escaped state. Emit a U+003C LESS-THAN SIGN character token and a U+002F SOLIDUS character token. Reconsume the current input character.

8.2.4.27 Script data escaped end tag name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

If the current end tag token is an appropriate end tag token, then switch to the before attribute name state. Otherwise, treat it as per the "anything else" entry below.

"/" (U+002F)

If the current end tag token is an appropriate end tag token, then switch to the self-closing start tag state. Otherwise, treat it as per the "anything else" entry below.

U+003E GREATER-THAN SIGN (>)

If the current end tag token is an appropriate end tag token, then switch to the data state and emit the current tag token. Otherwise, treat it as per the "anything else" entry below.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current tag token's tag name. Append the current input character to the temporary buffer.

Lowercase ASCII letter

Append the current input character to the current tag token's tag name. Append the current input character to the temporary buffer.

Anything else

Switch to the script data escaped state. Emit a U+003C LESS-THAN SIGN character token, a U+002F SOLIDUS character token, and a character token for each of the characters in the temporary buffer (in the order they were added to the buffer). Reconsume the current input character.

8.2.4.28 Script data double escape start state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

"/" (U+002F)

U+003E GREATER-THAN SIGN (>)

If the temporary buffer is the string "script", then switch to the script data double escaped state. Otherwise, switch to the script data escaped state. Emit the current input character as a character token.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the temporary buffer. Emit the current input character as a character token.

Lowercase ASCII letter

Append the current input character to the temporary buffer. Emit the current input character as a character token.

Anything else

Switch to the script data escaped state. Reconsume the current input character.

8.2.4.29 Script data double escaped state

Consume the next input character:

"-" (U+002D)

Switch to the script data double escaped dash state. Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data double escaped less-than sign state. Emit a U+003C LESS-THAN SIGN character token.

U+0000 NULL

Parse error. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Emit the current input character as a character token.

8.2.4.30 Script data double escaped dash state

Consume the next input character:

"-" (U+002D)

Switch to the script data double escaped dash dash state. Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data double escaped less-than sign state. Emit a U+003C LESS-THAN SIGN character token.

U+0000 NULL

Parse error. Switch to the script data double escaped state. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Switch to the script data double escaped state. Emit the current input character as a character token.

8.2.4.31 Script data double escaped dash dash state

Consume the next input character:

"-" (U+002D)

Emit a U+002D HYPHEN-MINUS character token.

U+003C LESS-THAN SIGN (<)

Switch to the script data double escaped less-than sign state. Emit a U+003C LESS-THAN SIGN character token.

U+003E GREATER-THAN SIGN (>)

Switch to the script data state. Emit a U+003E GREATER-THAN SIGN character token.

U+0000 NULL

Parse error. Switch to the script data double escaped state. Emit a U+FFFD REPLACEMENT CHARACTER character token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Switch to the script data double escaped state. Emit the current input character as a character token.

8.2.4.32 Script data double escaped less-than sign state

Consume the next input character:

"/" (U+002F)

Set the temporary buffer to the empty string. Switch to the script data double escape end state. Emit a U+002F SOLIDUS character token.

Anything else

Switch to the script data double escaped state. Reconsume the current input character.

8.2.4.33 Script data double escape end state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

"/" (U+002F)

U+003E GREATER-THAN SIGN (>)

If the temporary buffer is the string "script", then switch to the script data escaped state. Otherwise, switch to the script data double escaped state. Emit the current input character as a character token.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the temporary buffer. Emit the current input character as a character token.

Lowercase ASCII letter

Append the current input character to the temporary buffer. Emit the current input character as a character token.

Anything else

Switch to the script data double escaped state. Reconsume the current input character.

8.2.4.34 Before attribute name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Ignore the character.

"/" (U+002F)

Switch to the self-closing start tag state.

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

Uppercase ASCII letter

Start a new attribute in the current tag token. Set that attribute's name to the lowercase version of the current input character (add 0x0020 to the character's code point), and its value to the empty string. Switch to the attribute name state.

U+0000 NULL

Parse error. Start a new attribute in the current tag token. Set that attribute's name to a U+FFFD REPLACEMENT CHARACTER character, and its value to the empty string. Switch to the attribute name state.

U+0022 QUOTATION MARK (")

"'" (U+0027)

U+003C LESS-THAN SIGN (<)

"=" (U+003D)

Parse error. Treat it as per the "anything else" entry below.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Start a new attribute in the current tag token. Set that attribute's name to the current input character, and its value to the empty string. Switch to the attribute name state.

8.2.4.35 Attribute name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Switch to the after attribute name state.

"/" (U+002F)

Switch to the self-closing start tag state.

"=" (U+003D)

Switch to the before attribute value state.

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

Uppercase ASCII letter

Append the lowercase version of the current input character (add 0x0020 to the character's code point) to the current attribute's name.

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current attribute's name.

U+0022 QUOTATION MARK (")

"'" (U+0027)

U+003C LESS-THAN SIGN (<)

Parse error. Treat it as per the "anything else" entry below.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current attribute's name.

When the user agent leaves the attribute name state (and before emitting the tag token, if appropriate), the complete attribute's name must be compared to the other attributes on the same token; if there is already an attribute on the token with the exact same name, then this is a parse error and the new attribute must be dropped, along with the value that gets associated with it (if any).

8.2.4.36 After attribute name state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Ignore the character.

"/" (U+002F)

Switch to the self-closing start tag state.

"=" (U+003D)

Switch to the before attribute value state.

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

Uppercase ASCII letter

Start a new attribute in the current tag token. Set that attribute's name to the lowercase version of the current input character (add 0x0020 to the character's code point), and its value to the empty string. Switch to the attribute name state.

U+0000 NULL

Parse error. Start a new attribute in the current tag token. Set that attribute's name to a U+FFFD REPLACEMENT CHARACTER character, and its value to the empty string. Switch to the attribute name state.

U+0022 QUOTATION MARK (")

"'" (U+0027)

U+003C LESS-THAN SIGN (<)

Parse error. Treat it as per the "anything else" entry below.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Start a new attribute in the current tag token. Set that attribute's name to the current input character, and its value to the empty string. Switch to the attribute name state.

8.2.4.37 Before attribute value state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Ignore the character.

U+0022 QUOTATION MARK (")

Switch to the attribute value (double-quoted) state.

U+0026 AMPERSAND (&)

Switch to the attribute value (unquoted) state. Reconsume the current input character.

"'" (U+0027)

Switch to the attribute value (single-quoted) state.

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current attribute's value. Switch to the attribute value (unquoted) state.

U+003E GREATER-THAN SIGN (>)

Parse error. Switch to the data state. Emit the current tag token.

U+003C LESS-THAN SIGN (<)

"=" (U+003D)

"`" (U+0060)

Parse error. Treat it as per the "anything else" entry below.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current attribute's value. Switch to the attribute value (unquoted) state.

8.2.4.38 Attribute value (double-quoted) state

Consume the next input character:

U+0022 QUOTATION MARK (")

Switch to the after attribute value (quoted) state.

U+0026 AMPERSAND (&)

Switch to the character reference in attribute value state, with the additional allowed character being U+0022 QUOTATION MARK (").

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current attribute's value.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current attribute's value.

8.2.4.39 Attribute value (single-quoted) state

Consume the next input character:

"'" (U+0027)

Switch to the after attribute value (quoted) state.

U+0026 AMPERSAND (&)

Switch to the character reference in attribute value state, with the additional allowed character being "'" (U+0027).

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current attribute's value.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current attribute's value.

8.2.4.40 Attribute value (unquoted) state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Switch to the before attribute name state.

U+0026 AMPERSAND (&)

Switch to the character reference in attribute value state, with the additional allowed character being U+003E GREATER-THAN SIGN (>).

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

U+0000 NULL

Parse error. Append a U+FFFD REPLACEMENT CHARACTER character to the current attribute's value.

U+0022 QUOTATION MARK (")

"'" (U+0027)

U+003C LESS-THAN SIGN (<)

"=" (U+003D)

"`" (U+0060)

Parse error. Treat it as per the "anything else" entry below.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Append the current input character to the current attribute's value.

8.2.4.41 Character reference in attribute value state

Attempt to consume a character reference.

If nothing is returned, append a U+0026 AMPERSAND character (&) to the current attribute's value.

Otherwise, append the returned character tokens to the current attribute's value.

Finally, switch back to the attribute value state that switched into this state.

8.2.4.42 After attribute value (quoted) state

Consume the next input character:

"tab" (U+0009)

"LF" (U+000A)

"FF" (U+000C)

U+0020 SPACE

Switch to the before attribute name state.

"/" (U+002F)

Switch to the self-closing start tag state.

U+003E GREATER-THAN SIGN (>)

Switch to the data state. Emit the current tag token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Parse error. Switch to the before attribute name state. Reconsume the character.

8.2.4.43 Self-closing start tag state

Consume the next input character:

U+003E GREATER-THAN SIGN (>)

Set the self-closing flag of the current tag token. Switch to the data state. Emit the current tag token.

EOF

Parse error. Switch to the data state. Reconsume the EOF character.

Anything else

Parse error. Switch to the before attribute name state. Reconsume the character.

8.2.4.44 Bogus comment state

Consume every character up to and including the first U+003E GREATER-THAN SIGN character (>) or the end of the file (EOF), whichever comes first. Emit a comment token whose data is the concatenation of all the characters starting from and including the character that caused the state machine to switch into the bogus comment state, up to and including the character immediately before the last consumed character (i.e. up to the character just before the U+003E or EOF character), but with any U+0000 NULL characters replaced by U+FFFD REPLACEMENT CHARACTER characters. (If the comment was started by the end of the file (EOF), the token is empty. Similarly, the token is empty if it was generated by the string "<!>".)

Switch to the data state.

If the end of the file was reached, reconsume the EOF character.