samples/iyi/formatting.iyi

# Negative indexing and the small formatting set — README "What is not here".
#
#   ./bin/iyi run samples/iyi/formatting.iyi
#
# `a[-1]` counts from the end. `to_s(base)` writes a number in base 2 through
# 36. `rjust` / `ljust` pad, `*` repeats. There is no format-string parser;
# these are the methods a table and a hex dump actually need.

module samples/formatting

a = [10, 20, 30]
puts "last #{a[-1]}"
puts "first #{a[-a.size]}"

a[-1] = 99
puts "written #{a[-1]}"

s = "hello"
puts "char #{s[-1]}"
puts "slice #{s[-2, 2]}"

n = 255
puts "hex #{n.to_s(16)}"
puts "bin #{5.to_s(2)}"

cell = "ab"
puts "rjust '#{cell.rjust(5)}'"
puts "ljust '#{cell.ljust(5, '*')}'"
puts "rep #{cell * 3}"

puts "nil #{a[-4]?.inspect}"
puts "maybe #{a[-1]?.inspect}"