This simple code:

library(GenomicRanges)

GRanges(c("chr1", "chr1", "chr1"), c(109810200, 109810201, 109810544))

fails with rather cryptic exception:

> Error in validObject(.Object) : invalid class “GRanges” object: 1:
> 'x@seqnames' is not parallel to 'x' invalid class “GRanges” object: 2:
> 'x@strand' is not parallel to 'x'

Additionally when I try to provide seqlengths:

GRanges(
  c("chr1", "chr1", "chr1"), 
  c(109810200, 109810201, 109810544),
  seqlengths=c(1, 1, 1))

I get:

>    Error in .normargSeqlengths(seqlengths, seqnames) : length of supplied 'seqlengths' must equal the number of sequences

which suggests that some data is dropped in the process. But I cannot figure out why it happens.

I'd be grateful for any insights into what's going on here.

Environment:

> sessionInfo()
R version 3.5.2 (2018-12-20)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Debian GNU/Linux buster/sid

Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.8.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.8.0

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] parallel  stats4    stats     graphics  grDevices utils     datasets 
[8] methods   base     

other attached packages:
[1] GenomicRanges_1.34.0 GenomeInfoDb_1.18.2  IRanges_2.16.0      
[4] S4Vectors_0.20.1     BiocGenerics_0.28.0 

loaded via a namespace (and not attached):
[1] zlibbioc_1.28.0        compiler_3.5.2         XVector_0.22.0        
[4] GenomeInfoDbData_1.2.0 RCurl_1.95-4.12        bitops_1.0-6

Funny thing is that if you switch the second number by +1, it works: Try:

GRanges(c("chr1", "chr1", "chr1"), c(109810200, 109810202, 109810544)) # 202, instead of 201

If you write ?GRanges, you see the ranges argument if defined as:

IRanges, or single integer range, where integer values next to each other are merged. i.g c(1,2,3), is one range from 1 to 3

To fix your statement do:

GRanges(seqnames = "chr1", ranges =  IRanges(c(109810200, 109810201, 109810544), width = 1))

One funny thing with GRanges is that if you give this:

GRanges(seqnames = "chr1", ranges =  IRanges(c(1,2,3), width = 1))

You get:

GRanges object with 3 ranges and 0 metadata columns:
      seqnames    ranges strand
         <Rle> <IRanges>  <Rle>
  [1]     chr1         1      *
  [2]     chr1         2      *
  [3]     chr1         3      *
  -------

But if you give this:

GRanges(seqnames = "chr1", ranges =  c(1,2,3))

GRanges object with 1 range and 0 metadata columns:
      seqnames    ranges strand
         <Rle> <IRanges>  <Rle>
  [1]     chr1       1-3      *
  -------

And even cooler I would say, this:

GRanges(seqnames = "chr1", ranges =  c(1,2,3, 5))

Gives you:

GRanges object with 2 ranges and 0 metadata columns:
      seqnames    ranges strand
         <Rle> <IRanges>  <Rle>
  [1]     chr1       1-3      *
  [2]     chr1         5      *
  -------