A message needs a trailing newline

[franknarf1]

This is very minor. There should be a "\n" (or something) at the end of this message:

data.table/R/fmelt.R

Line 33 in d607425

cat("Duplicate column names found in molten data.table. Setting unique names using 'make.names'")

Example from SO http://stackoverflow.com/q/35510535/1191259

DF = structure(list(value = 1:5, name = structure(1:5, .Label = c("A", 
"B", "C", "D", "F"), class = "factor"), X2015.cost = c(100, 200, 
250, 300, 450), X2016.cost = c(200, 300, 350, 400, 550), X2017.cost = c(300, 
400, 450, 500, 650), X2015.profit = c(1000, 4200, 2450, 1500, 
7650), X2016.profit = c(1300, 4300, 3450, 5100, 6850), X2017.profit = c(1300, 
4400, 6450, 5001, 6500)), .Names = c("value", "name", "X2015.cost", 
"X2016.cost", "X2017.cost", "X2015.profit", "X2016.profit", "X2017.profit"
), row.names = c(NA, -5L), class = "data.frame")

dcast(melt(DF, id.vars = c("value","name"))[, 
    c("year", "col_type") := tstrsplit(variable, "\\.")
][,
    year := as.integer(sub("\\D","", year))
], value+name+year ~ col_type)

# which produces...
Duplicate column names found in molten data.table. Setting unique names using 'make.names'    value name year cost profit
 1:     1    A 2015    1      1
 2:     1    A 2016    1      1
 3:     1    A 2017    1      1
 4:     2    B 2015    2      2
 5:     2    B 2016    2      2
 6:     2    B 2017    2      2
 7:     3    C 2015    3      3
 8:     3    C 2016    3      3
 9:     3    C 2017    3      3
10:     4    D 2015    4      4
11:     4    D 2016    4      4
12:     4    D 2017    4      4
13:     5    F 2015    5      5
14:     5    F 2016    5      5
15:     5    F 2017    5      5

Note that the column names in the result are on the same line as the preceding warning/notification.

[MichaelChirico]

Seems "\n" is the standard approach for data.table:

https://github.com/Rdatatable/data.table/search?utf8=%E2%9C%93&q=cat

PR encouraged =D

[arunsrinivasan]

PRs are much better fit for these types of issues.