Naw

Naw is a small glue wrapper around nim to do awk-style text processing with it.

Installation

nimble install naw

Usage

Launch it with naw '...nim code...' inputting data to stdin. The following example generates a markdown table from CSV.

echo 'foo,1
bar,2
fuz,3
buz,4' | naw -F, 'My Report
===========

{"":-<20} {"":-<20}
# for r in rows():
{r[0]:<20} {r[1]:>20}
# end
{"":-<20} {"":-<20}
# for r in rows():
{r[0]} {r[1]}
# end
'

yields

My Report  
===========

-------------------- --------------------
foo                                     1
bar                                     2
fuz                                     3
buz                                     4
-------------------- --------------------

Features

Complete Nim syntax is supported through the stdtmpl source code filter. Complete nim strformat syntax is supported for output.

Additional convenience syntax is added:

---

rows() Iterator to iterate through a CSV stdin, using the seperator rows("filename") specified with -F

+ Unary plus-sign, synonymous for parseInt ~ Unary tilde, synonymous for parseFloat

---

Requirements

naw requires the Nim compiler to work.

Internals

naw bolts strformat onto the stdtmpl language and adds some glue, resulting in a really concise templating language for text formatting form CSV data, which is exactly what awk's domain is.

If you don't mind creating a file to compile, you can get very similar results to naw with pure nim

#? stdtmpl(emit="stdout.write &")
# import strformat, streams, parsecsv
# var x: CsvParser
# open(x, newFileStream(stdin), "-", '\t')

My Report
=========

{"":-<20} {"":-<20}
# while x.readRow():
{x.row[0]:<20} {x.row[1]:>20}
# end
{"":-<20} {"":-<20}

naw just allows you to pass the code as a command line parameter, which is nice if you're familiar with awk, and auto-imports strformat, streams and parsecsv as well as adding some shorthand syntax of its own.

Limitations

Naw is experimental but small enough to work reasonably well off the bat. Install a specific version for to avoid changes.

  nimble install naw@0.1.0

License

naw is MIT-Licensed