multiple columns with multiple values

[nsheff]

Verision 0.2.1 can't handle multiple columns with multiple values.

In other words, if you use a subsample_table that has multiple columns, it will choke with this kind of error:

onfig file: /home/x/code/ews_patients/metadata/project_config.yaml
Loaded config file: /home/x/code/ews_patients/metadata/project_config.yaml
  subprojects: rna,cellrep,bsdat
Error in `[[<-`(`*tmp*`, pluralID, value = iPlural) : 
  recursive indexing failed at level 2

Enter a frame number, or 0 to exit   

1: projectInit("ews_patients")
2: pepr::Project(cfgFile, subproject)
3: methods::new("Project", file = file, subproject = subproject)
4: initialize(value, ...)
5: initialize(value, ...)
6: .deriveAttributes(.Object)
7: .strformat(regex, as.list(samp), exclude, parentDir)

I traced the problem to the .strformat function, which is only tested with 1 multi-variable:

.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1="hi", VAR2="hello"))
.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1="hi", VAR2="hello"))
.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1="hi", VAR2=c("hello", "hello2")))
.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1="hi", VAR2=c("hello", "hello2", "hello3")))

These should also be possible:

.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1=c("hi", "hi2"), VAR2=c("hello", "hello2")))
.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1=c("hi", "hi2"), VAR2=c("hello", "hello2")))

What I've realized is, mutliple multi-variables should be allowed, as long as they each have exactly the same number of values. So, this should fail:

.strformat("$HOME/{VAR1}{VAR2}_file", list(VAR1=c("hi", "hi2"), VAR2=c("hello", "hello2", "hello3")))