# Examples
library(dplyr)

source("s_dplyr.R");
# Original usage of dplyr
mtcars %>%
  filter(gear == 3,cyl == 8) %>%  
  select(mpg, cyl, hp:vs)

# Select user specified cols.
# Note that you can have a vector of strings
# or a single string separated by ',' or a mixture of both
cols = c("mpg","cyl, hp:vs")
mtcars %>%
  filter(gear == 3,cyl == 8) %>%  
  s_select(cols)

# Filter using a string
col = "gear"
mtcars %>%
  s_filter(paste0(col,"==3"), "cyl==8" ) %>%
  select(mpg, cyl, hp:vs)

# Arrange without using %>%
s_arrange(mtcars, "-mpg, gear, carb")

# group_by and summarise with strings
mtcars %>%
  s_group_by("cyl") %>%  
  s_summarise("mean(disp), max(disp)")

mtcars %>%
  s_group_by("cyl") %>%
  s_summarise(paste(paste0("mean(", colnames(mtcars),")"), collapse=","))