nimforum mirror - Does Nimrod have a heredoc syntax?

timothee (orginal) [2018-04-16T20:28:47+02:00] view original

""" can't contain """ . Heredoc solves this issue by allowing user defined string delimiter.

Here's a heredoc string literal in D. Some other languages have that too (eg C++11, ruby etc); see https://dlang.org/spec/lex.html note, user can use anything, not just EOS; that's what makes them universally applicable.


auto s = q"EOS
This is a multi-line
heredoc string
EOS"

in Nim, this could look like:

let s= h"EOS we can have anything including """ inside it EOS"

NOTE: in D, the delimiter has to be in its own line and the last newline is part of the string, making it impossible to define a heredoc string without trailing newline.

In nim, it would be nice if that limitation were lifted; I'd suggest the following instead:

option 1: omit the trailing newline; if a user needs a trailing newline, he'd write instead an additional blank line:

let s= h"EOS we can have anything including """ inside it

EOS"

option 2 (my favorite): make the delimiter enclosed in () as follows:

let s= h"EOS(we can have anything including """ inside it)EOS"

which is allows to fit in 1 line, and doesnt' have limitation of string ending in newline

this is one thing where C++ designed it better than D IMO (see also https://stackoverflow.com/questions/19075999/what-is-the-rationale-for-parenthesis-in-c11s-raw-string-literals-r)

let s=h"!(put anything here except user defined delimiter!)" let s="""put anything here except triple quote"""

in short: heredoc is occasionally quite useful, eg if we need to write nim source code inside a string, where the source code itself contains triple quotes.

Mirror of forum.nim-lang.org

471 :: Does Nimrod have a heredoc syntax?

NOTE: in D, the delimiter has to be in its own line and the last newline is part of the string, making it impossible to define a heredoc string without trailing newline.