breaking: no escape at all in triple quotes #290
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Prior to this breaking change, backslashes inside triple-quotes
are treated as escape sequence.
This design allowed the last string character to be " as long
as it's escaped.
key = """\"string value with quotes\""""
Which lead to the need of escaping backslash itself.
The need of escaping backslash inside triple-quote string
not only violate the HOCON spec, but also make it hard for users
to hand-craft multe-line string values.
For example, when writing EMQX rule-engine SQL program:
sql = """SELECT tokens(payload, b'\n')"""
would actually require users to write
sql = """SELECT tokens(payload, b'\\n')"""
this is quite counter counterintuitive.
The cost of having to escape \ is probably higher
than the gain of supporting escape sequence in tripe-quote strings.
After this change, 4-quotes is syntax error, and tripe-quote as value is
no longer possible (due to lack of escape sequence).
However, there are work arounds:
- A string ending with " can be wrapped with """~ and ~""" instead.
e.g.
key = """~
"string value with quotes"~"""
- Use normal quotes with escape sequence: "\"\"\""
- Make use of string concatenation feature: quote the proceeding
characters using tripe-quotes, quote """ as "\"\"\"", then quote the
following characters with triple-quotes again.
e.g.
key = """~
line1
~"""
"line2\"\"\"\n"
"""~
line3
~"""
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Prior to this breaking change, backslashes inside triple-quotes are treated as escape sequence.
This design allowed the last string character to be
"as long as it's escaped.Which had its advantages however lead to the need of escaping backslash itself.
The need of escaping backslash inside triple-quote string
not only violate the HOCON spec, but also make it hard for users
to hand-craft multe-line string values.
For example, when writing EMQX rule-engine SQL program:
would actually require users to write
-- which is quite counter counterintuitive.
The cost of having to escape
\will probably be higherthan the gain of supporting escape sequence in tripe-quote strings.
After this change, 4-quotes is syntax error, and tripe-quote as value is no longer possible (due to lack of escape sequence).
However, there are workarounds:
A string ending with
"can be wrapped with"""~and~"""instead.e.g.
Use normal quotes with escape sequence:
"\"\"\""Make use of string concatenation feature: quote the proceeding characters using tripe-quotes, quote
"""as"\"\"\"", then quote the following characters with triple-quotes again.e.g.