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README.md

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+# N___ RegEx Library
+
+## What is NRE?
+
+A new regular expression library for Nim using PCRE to do the hard work.
+
+## Why?
+
+The [re.nim][] module that [Nim][] provides in it's standard library is
+inadequate:
+
+ - It provides only a limited number of captures, while the underling library
+ (PCRE) allows an unlimited number.
+ - Instead of having one proc that returns both the bounds and substring, it
+ has one for the bounds and another for the substring.
+ - If the splitting regex is empty (`""`), then it returns the input string
+ instead of following [Perl][], [Javascript][], and [Java][]'s precedent of
+ returning a list of each character (`"123".split(re"") == @["1", "2", "3"]`).
+
+[re.nim]: http://nim-lang.org/re.html
+[Nim]: http://nim-lang.org/
+[Perl]: https://ideone.com/dDMjmz
+[Javascript]: http://jsfiddle.net/xtcbxurg/
+[Java]: https://ideone.com/hYJuJ5
+
+
+# Documentation
+
+## Construction
+
+Creating a pattern is easy: `re"([0-9]+)"`. By default, the extended flag is
+passed in order to encourage readable expressions, so `[0-9]+` is equivalent to
+`[0-9] +  # foo`. If you'd like to pass your own flags, then `re(r"([0-9]+)",
+"<flags>")` will work. Here is a list of the available flags:
+
+  - `8` - treat both the pattern and subject as UTF8
+  - `9` - prevents the pattern from being interpreted as UTF, no matter what
+  - `A` - as if the pattern had a `^` at the beginning
+  - `E` - DOLLAR_ENDONLY
+  - `f` - fails if there is not a match on the first line
+  - `i` - case insensitive
+  - `m` - multi-line, `^` and `$` match the beginning and end of lines, not of
+  the subject string
+  - `N` - turn off auto-capture, `(?foo)` is necessary to capture.
+  - `s` - `.` matches newline
+  - `U` - expressions are not greedy by default. `?` can be added to a
+  qualifier to make it greedy.
+  - `u` - same as `8`
+  - `W` - Unicode character properties
+  - `X` - "Extra", character escapes without special meaning (`\w` vs. `\a`)
+  are errors
+  - `x` - extended, comments (`#`) and newlines are ignored (extended)
+  - `Y` - pcre.NO_START_OPTIMIZE,
+  - `<cr>` - newlines are separated by `\r`
+  - `<crlf>` - newlines are separated by `\r\n` (Windows default)
+  - `<lf>` - newlines are separated by `\n` (UNIX default)
+  - `<anycrlf>` - newlines are separated by any of the above
+  - `<any>` - newlines are separated by any of the above and Unicode newlines:
+  > single characters VT (vertical tab, U+000B), FF (form feed, U+000C), NEL
+  > (next line, U+0085), LS (line separator, U+2028), and PS (paragraph
+  > separator, U+2029). For the 8-bit library, the last two are recognized
+  > only in UTF-8 mode.
+  - `<bsr_anycrlf>` - `\R` matches CR, LF, or CRLF
+  - `<bsr_unicode>` - `\R` matches any unicode newline
+  - `<js>` - Javascript compatibility
+
+`Sx` is enabled by default in order to encourage use of whitespace for better
+readability.