STDIN.ready? (crystal-lang) - crystal-lang

Question

My current ruby commandline app uses STDIN.ready?. This permits me to capture complex keys such as Meta keys, Function keys, shifted-function keys etc.
I am not finding anything similar in Crystal.
While searching I found STDIN.raw &.read_char.
According to the docs, this should return a nil when there is nothing to read. However, I am not getting a nil. It seems to wait for the next key. The ruby code had a $stdin.getc.
My logic basically keeps reading STDIN as long as it is ready and accumulating key codes. The moment ready? returns false, the key is evaluated.
The logic NOW is:
c = STDIN.raw &.read_char
if c == '\e' # escape char
loop do
k = STDIN.raw &.read_char
if k
# accumulate k into a string
else
# evaluate string and return
end
end #loop
end
# rest of code if not escape.
Currently the else condition does not execute, so I am stuck in the if part. I don't know when to stop reading keys.
Previously, in ruby I had the second getc inside a if STDIN.ready?.
Earlier in ruby:
if c == '\e'
loop
if STDIN.ready?
k = STDIN.getc
accumulate in string
else
evaluation string and return code
end
end
end
EDIT: for me the correct answer lies in the link to 2048.cr suggested below in a comment.

Answer 1

This is not an answer, it is just a workaround if no correct answers here.
def handle_second_key(buffer)
loop do
input = STDIN.raw &.read_char
buffer << input if input
if buffer.size == 2
if buffer[0] == '\e' && buffer[1] == 'q'
puts "Right combination #{buffer[0].dump} + #{buffer[1].dump}"
exit
else
puts "Wrong combination: #{buffer[0].dump} + #{buffer[1].dump}"
break
end
end
end
end
buffer = [] of Char
loop do
input = STDIN.raw &.read_char
buffer << input if input
if buffer[0] == '\e'
handle_second_key(buffer)
buffer.clear
else
buffer.clear if buffer.size > 0
end
end