Import the package. We will also make heavy usage of magrittr for chaining, dplyr for filtering, and knitr for printing.
library(easyformatr)
library(magrittr)
library(dplyr)
library(knitr)Let’s see what kind of componenets we can use in our time formats. This can be done by filtering the format info table.
filter_info(type == "time" & component == "base")| code | base |
|---|---|
| p | am_pm |
| C | century |
| F | date |
| c | datetime |
| d | day |
| w | day_of_week |
| j | day_of_year |
| H | hour |
| M | minute |
| m | month |
| n | newline |
| S | second |
| R | time |
| s | timestamp |
| Z | timezone |
| V | week_of_year |
| t | tab |
| Y | year |
filter_info(type == "number" & component == "base")| code | base |
|---|---|
| i | integer |
| o | octal |
| x | hex |
| f | double |
| e | scientific |
| g | auto |
| a | binary |
Each of these base components can be used in a formats.
easy_format(year, month, day, integer, octal, double)## %Y%m%d%.i%.o%.fEach base component can be modified in special ways.
Each time base can be modified in different ways. Let’s look at ways to modify second:
filter_info(type == "time" & component == "mutant" & base == "second")| code | decimal | digits |
|---|---|---|
| 0S | TRUE | NA |
| 0S0 | NA | 0 |
| 0S1 | NA | 1 |
| 0S2 | NA | 2 |
| 0S3 | NA | 3 |
| 0S4 | NA | 4 |
| 0S5 | NA | 5 |
| 0S6 | NA | 6 |
Along the top, you can see the names of flags and options. Flags change logical variables, and options change numeric variables.
It is slightly easier to see modifiers for numbers because there is a fixed set.
filter_info(type == "number" & component == "flag")| code | flag |
|---|---|
| - | left_justify |
| + | always_sign |
| prefix_space | |
| 0 | zero_pad |
| # | hex_prefix |
| # | always_decimal |
| # | remove_zeros |
filter_info(type == "number" & component == "option")| option | description |
|---|---|
| before_decimal | number of digits before the decimal place |
| after_decimal | number of digits after the decimal place |
| use_input | sprintf input argument number |
To transform a base into a mutant, you must use a flag or option function. These functions take two arguments. The first is an object to modify:
easy_format(second %>% decimal)## %0Sor a list of objects to modify:
easy_format(list(integer,
double) %>%
always_decimal)## %#.i%#.for even a nested list of objects to modify
easy_format(list(month,
list(day,
minute) ) %>%
roman)## %0m%0d%0MIn the case of times, flags or options that aren’t relevant to a particular base (that is, aren’t listed in the mutant table for a particular base) have no effect. Flags and options always have an effect on numbers.
easy_format(second %>% roman) ==
easy_format(second)## [1] TRUEThe second argument of a transformation is what to change the value to.
For flags, the second argument defaults to true.
easy_format(second %>% decimal) ==
easy_format(second %>% decimal(TRUE) )## [1] TRUEFlags can be undone by resetting the value to NA.
easy_format(second %>%
decimal %>%
decimal(NA) ) ==
easy_format(second)## [1] TRUEFor options, this second value defaults to NA. So options will have no effect if no number is chosen.
easy_format(double %>% before_decimal) ==
easy_format(double)## [1] TRUEOptions can be turned of by resetting them to NA
easy_format(double %>% before_decimal(3) %>% before_decimal) ==
easy_format(double)## [1] TRUEFor times, it is possible to specify a mutant that has no corresponding code. For example,
easy_format(second %>%
decimal %>%
digits(1) ) ## Error in function_list[[k]](value):
##
## base decimal digits
## ------- -------- -------
## second TRUE 1
##
## has no corresponding codeEasy format leaves strings unchanged. However, percentage signs will be doubled.
easy_format("We are the 99%")## We are the 99%%This only happens once.
easy_format(easy_format("We are the 99%") )## We are the 99%%Modifications also leave strings unchanged.
easy_format(roman("I am Spartacus"))## I am SpartacusThere is an optional sep argument that defaults to "", but can be changed.
easy_format("We", "are", "the 99%", sep = " ")## We are the 99%%For more information, codes can be looked up in the ?strptime and the ?sprintf documentation. Note that many formats are possible to build but will not work when used.