Parse the text from the C-string s holding len
bytes and put the resulting term in t. len can be (size_t)-1,
assuming a 0-terminated string. The flags argument controls
the encoding and is currently one of REP_UTF8 (string is
UTF8 encoded), REP_MB (string is encoded in the current
locale) or 0 (string is encoded in ISO latin 1). The string may, but is
not required, to be closed by a full stop (.).
If parsing produces an exception; the behaviour depends on the
CVT_EXCEPTION flag. If present, the exception is propagated
into the environment. Otherwise, the exception is placed in t
and the return value is FALSE.221The CVT_EXCEPTION
was added in version 8.3.12.
