regex101: CommonMark Fenced Code Blocks (78% Spec Compliant)

Pro

^start of line

{0,3}the literal (32₁₀ / 40₈ / 20₁₆) , repeated between 0 and 3 times

Group 1((?:(`){3,}?)|(?:(~){3,}?))

1st Alternative(?:(`){3,}?)

Non-Capturing Group(?:(`){3,}?)

Group 2(`){3,}?

{3,}?repeats the group contents below at least 3 times:

`the literal ` (96₁₀ / 140₈ / 60₁₆)

2nd Alternative(?:(~){3,}?)

Non-Capturing Group(?:(~){3,}?)

Group 3(~){3,}?

{3,}?repeats the group contents below at least 3 times:

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

Negative Lookahead(?!\2\3)

\2the text saved by group 2

\3the text saved by group 3

Non-Capturing Group(?:([^`\n]+?)(\1(?:\2\3)*)|(?:( *([^ \n]+)[^`\n]*)?\n([\s\S]*?)(^ {0,3}))(\1(?:\2\3)*)(?=$))

1st Alternative([^`\n]+?)(\1(?:\2\3)*)

Group 4([^`\n]+?)

Negated Character Class[^`\n]+?

+?matches at least one character outside the set below:

`the literal ` (96₁₀ / 140₈ / 60₁₆)

\na line-feed (newline) character (ASCII 10)

Group 5(\1(?:\2\3)*)

\1the text saved by group 1

Non-Capturing Group(?:\2\3)*

*repeats the group contents below any number of times:

\2the text saved by group 2

\3the text saved by group 3

2nd Alternative(?:( *([^ \n]+)[^`\n]*)?\n([\s\S]*?)(^ {0,3}))(\1(?:\2\3)*)(?=$)

Non-Capturing Group(?:( *([^ \n]+)[^`\n]*)?\n([\s\S]*?)(^ {0,3}))

Group 6( *([^ \n]+)[^`\n]*)?

?repeats the group contents below at most once:

*the literal (32₁₀ / 40₈ / 20₁₆) , repeated any number of times

Group 7([^ \n]+)

Negated Character Class[^ \n]+

+matches at least one character outside the set below:

the literal (32₁₀ / 40₈ / 20₁₆)

\na line-feed (newline) character (ASCII 10)

Negated Character Class[^`\n]*

*matches any number of characters outside the set below:

`the literal ` (96₁₀ / 140₈ / 60₁₆)

\na line-feed (newline) character (ASCII 10)

Group 8([\s\S]*?)

Character Class[\s\S]*?

*?matches any number of characters from the set below:

\sany whitespace character

\Sany non-whitespace character

Group 9(^ {0,3})

^start of line

{0,3}the literal (32₁₀ / 40₈ / 20₁₆) , repeated between 0 and 3 times

Group 10(\1(?:\2\3)*)

\1the text saved by group 1

Non-Capturing Group(?:\2\3)*

*repeats the group contents below any number of times:

\2the text saved by group 2

\3the text saved by group 3

Positive Lookahead(?=$)

Global pattern flags

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

g modifier: global. Finds all matches instead of stopping after the first

26 tokens

Regular Expression

^ {0,3}((?:(`){3,}?)|(?:(~){3,}?))(?!\2\3)(?:([^`\n]+?)(\1(?:\2\3)*)|(?:( *([^ \n]+)[^`\n]*)?\n([\s\S]*?)(^ {0,3}))(\1(?:\2\3)*)(?=$))

Regular Expressions 101

Regular Expression

Unit Tests