A.53 library(strings): String utilities
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Availability::- use_module(library(strings)).(can be autoloaded)
Source[det]indent_lines(+Prefix, +In, -Out)
Add Prefix to the beginning of lines in In. Lines are separated by "\n" -- conversion to and from external forms (such as "\r\n") are typically done by the I/O predicates. Lines that consist entirely of whitespace are left as-is.