add fread support for text= single line without \r or \n

[ben-schwen]

Closes #4689. fread(text = "a b c") works now and produces an data.table with 0 rows and 3 cols. Beforehand this resulted in an error because single line text without \r or \n was treated like fread(input = text).

[codecov]

Codecov Report

Merging #4703 (3328f68) into master (1b87849) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4703      +/-   ##
==========================================
- Coverage   99.51%   99.51%   -0.01%     
==========================================
  Files          76       76              
  Lines       14696    14694       -2     
==========================================
- Hits        14625    14623       -2     
  Misses         71       71              

Impacted Files	Coverage Δ
R/fread.R	100.00% <100.00%> (ø)
src/freadR.c	100.00% <100.00%> (ø)

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[torbjorn]

Is this really fixed? I'm seeing this with 1.14.2:

    > packageVersion("data.table")
    [1] ‘1.14.2’
    > fread(text="a,b,c\n", header=F)
       V1 V2 V3
    1:  a  b  c
    > fread(text="a,b,c", header=F)
    Error in fread(text = "a,b,c", header = F) : file not found: a,b,c
    > 

[ben-schwen]

@torbjorn this is fixed in the current dev-version. The added milestone might be misleading. You can update to the dev-version via data.table:::update.dev.pkg()

This will also not be fixed with 1.14.4 which was recently submitted to CRAN.

[mattdowle]

@ben-schwen @torbjorn once 1.14.4 is accepted on CRAN, I'll tag that in the patch-14.4 branch and then probably move forward with backporting bug fixes like this to 1.14.6 on that branch together with new features in dev that are stable and which shouldn't have any impact revdeps; e.g. the new env= argument.
The milestone does say 1.14.5 though so I'm not sure what's misleading there.

[ben-schwen]

@mattdowle It's true once I click on the milestone or check the milestone below it says 1.14.5. In the timeline of commits, mentions and merges it is still displayed as 1.14.1 (see following image)

[mattdowle]

Thanks. Yes it's the same milestone that's since been renamed. Both the closed issue and the closed PR are marked 1.14.5 on the right though. Maybe in future then we should have a 'dev' or 'unstable' milestone and then move items to the release branch. Like R-devel does it.

[torbjorn]

It's 1.14.8 now and this seems not to be fixed:

> fread( text="hi,ho,silver", header=FALSE )
Error in fread(text = "hi,ho,silver", header = FALSE) : 
  file not found: hi,ho,silver

with a newline:

> fread( text="hi,ho,silver\n", header=FALSE )
   V1 V2     V3
1: hi ho silver

version:

> packageVersion("data.table")
[1] ‘1.14.8’

[ben-schwen]

@torbjorn this is fixed in the current dev version. 1.14.2 - 1.14.8 were only small updates fixing things to keep it on CRAN, accommodate R dev version, etc. The milestone on the right also points towards 1.14.9