Support string constants with c-style escapes. Example:
From PostgreSQL documentation 22.214.171.124. String Constants With C-Style Escapes:
An escape string constant is specified by writing the letter E (upper or lower case) just before the opening single quote, e.g., E'foo'. (When continuing an escape string constant across lines, write E only before the first opening quote.) Within an escape string, a backslash character () begins a C-like backslash escape sequence, in which the combination of backslash and following character(s) represent a special byte value, as shown in Table:
|Backslash Escape Sequence||Interpretation|
|\o, \oo, \ooo (o = 0–7)||octal byte value|
|\xh, \xhh (h = 0–9, A–F)||hexadecimal byte value|
|\uxxxx, \Uxxxxxxxx (x = 0–9, A–F)||16 or 32-bit hexadecimal Unicode character value|
I suggest to not introduce any configuration flags for this feature because it seems like it does not contradict with any SQL dialect and it shouldn't slow down queries parsing.