Re: Resolving environment variables in a string

[squattingmonk]

Thanks, Araq! That's exactly what I needed.

Re: Resolving environment variables in a string

[squattingmonk]

I'm also noticing that this will throw an exception if any of the variables in 
the string are not found among the environment variables.

Resolving environment variables in a string

[squattingmonk]

Hi, all! I need to resolve environment variables in a string. I'm not seeing a 
proc for this in the standard library, so I whipped this up:


import os, strtabs

proc envTable: StringTableRef =
  result = newStringTable(modeCaseSensitive)
  for key, value in envPairs():
result[key] = value

let
  envs = envTable()
  path = paramStr(1)

echo path % envs


Run

Is there a better or more idomatic way to do this?

Re: Split on whitespace except for between quotes

[squattingmonk]

Thanks! I came up with the following:


import parseutils, strutils

proc splitArgs(args: string): seq[string] =
  var
parsed, tmp: string
i, quotes: int
  
  while i < args.len:
i += args.parseUntil(parsed, Whitespace, i) + 1
tmp.add(parsed)
if parsed.startsWith('"'):
  quotes.inc
if parsed.endsWith('"'):
  quotes.dec
elif quotes > 0:
  tmp.add(" ")

if quotes == 0:
  tmp.removePrefix('"')
  tmp.removeSuffix('"')
  result.add(tmp)
  tmp = ""
  
  if tmp.len > 0:
result.add(tmp[1 .. ^2])

let text = "spam eggs \"spam and eggs\""
doAssert text.splitArgs == @["spam", "eggs", "spam and eggs"]


Run

I chose not to cover single quotes because I don't want to have to handle words 
like "don't". Advice on how I could improve on this?

Re: Split on whitespace except for between quotes

[squattingmonk]

This text wouldn't be passed into the command line (it's read from a file), but 
it will be passed to it. Your suggestion turned me on to `parseCmdLine()` from 
the os module. It does exactly what I need. Thank you!

Split on whitespace except for between quotes

[squattingmonk]

I want to split a string on whitespace, but keep strings that are between 
quotes:


input: spam eggs "spam and eggs"
output: @["spam", "eggs", "spam and eggs"]

I want to support both single and double quotes, and I'm having trouble 
wrapping my brain around how to do this. I've been thinking maybe splitting 
with a regular expression is the way to go, but I wondered if there is a 
simpler way (perhaps already in the standard library that I've missed).

Re: Getting OrderedTable key/value pair by insertion order

[squattingmonk]

> So indeed iterating over the keys and stopping after first one makes sense, I 
> think there is no function to retrieve the first added element. And I think I 
> can remember someone asking how to get the n-th. added element, conclusion 
> was to use a loop similar as you do.

Thanks, Stefan. I'd though I was just being silly and missing something 
obvious. Good to know this is a reasonable solution.

> use 
> 
> 
> iterator pairs[A, B](t: OrderedTable[A, B]): (A, B)
> 
> 
> Run
> 
> and break-out after first (does "... in insertion order." kind of implies 
> FIFO?) element.

Hi, lucian. That's what I did in the code sample I provided, but I used the 
`keys` iterator instead of `pairs`.

Re: Getting OrderedTable key/value pair by insertion order

[squattingmonk]

I'm not trying to get sorted items, just the first item added (hence why I used 
an OrderedTable).

Getting OrderedTable key/value pair by insertion order

[squattingmonk]

Hi, all! I'm trying to get the first item out of an OrderedTable that was 
indexed with strings. I'm not sure which is the best way to do it.

My program is reading a set of configuration files and loading the information 
into a type `Target`, which is then added to an ordered table using the name of 
the target as its index. If the user executes a command that takes a target, I 
want to get the target using the supplied name as the index (just normalized). 
So far, so good. However, if the user does not specify a target, I want to 
select the first one that was added to the table.

Here's my types: 


type
  Config* = object
# ...
targets*: OrderedTable[string, Target]
  
  Target = object
name*, file*, description*: string
sources*: seq[string]


Run

This is the only way I can think of to get the first index: 


if opts.target.len == 0:
  for target in cfg.targets.keys:
opts.target = target
break
 

Run

Is there a better way of getting the first index? Or maybe a better way to 
structure my data that avoids this?

Thanks!