Documentation

Trailing commas can only be present in a parameter list of entirely positional arguments. This removes the bad trailing comma, and appends the comma's trailing whitespace to the previous token

Two non-typed single-quoted strings cannot be lexically adjacent, because this would be a parse error

eg. '''' or """"

we correct for this by inserting a single space where required '' '' or "" ""

When a backslash character, precedes an escape sequence it needs to be escaped so that it doesn't interfere with the backslash that begins the escape sequence.

For example:

[Char_lit '\\', Char_esc_n] would naively render to '\\n', which would parse to [Char_esc_bslash, Char_lit 'n'], breaking the parse . print identity

(as, bs) = span p xs bs is the longest suffix that satisfies the predicate, and as is the prefix up to that point

It's like the reverse of span

Sometimes strings need to be corrected when certain characters follow a literal backslash. For example, a literal backslash followed by an escape sequence means that the literal backslash actually needs to be escaped, so that it doesn't get combined with the backslash in the escape sequence.

It turns out that raw strings can only ever be constructed with an even number of trailing backslash characters. This functon corrects raw strings with an odd number of trailing backslash characters

Every quote in a string of a particular quote type should be escaped

Every quote in short raw string that isn't preceded by a backslash should be escaped

Every third literal quote at the beginning of a long (non-raw) string should be escaped

Literal quotes at the beginning and end of a long raw string should be escaped

Literal quotes at the beginning and end of a long (non-raw) string should be escaped

It's possible that successive statements have no newlines in between them. This would cause them to be displayed on the same line. In every line where this would be the case, we explicitly insert a line-feed character.