I am fairly new too crystal, so sorry if I am being a bit stupid. I have a string:
src = gets "> "
I am trying to loop through that string but I don't know how... What I have tried:
In cpp, I use : to loop through strings(or anything), I tried this, like so:
for i : src
# ...
and this:
for i: src
#...
And I also tried this:
for i >> src
#...
None of those work... I also tried this:
for i in src
# ...
Yet again, none of those work... why, and how can I fix this?
My full code:
src = gets "> "
for i : src
if i == '1'
puts "You entered one."
end
According to the Crystal docs using the each_char method of String you can iterate over each character in the string.
e.g.
array = [] of Char
"ab☃".each_char do |char|
array << char
end
array # => ['a', 'b', '☃']
Related
It's friday and I'm tired and my brain obvs doesn't want to find this answer. Please help.
I want to assign the value to an array. It works in subsequent lines but not in one particular line, even though syntax seems the same to me? It seems to think I'm calling a function??
for entry in PROJECT:
i = i + 1
#A
if entry.startswith("A") :
ProjectA(i) = entry
#B
elif entry.startswith("B"):
ProjectB(i)= entry
#C
elif entry.startswith("C") :
ProjectC(i) = entry
# and Programme
elif entry.startswith("D") :
ProjectD(i) = entry
I'm told the problem is the last line: "ProjectD(i) = entry". Which to me seems like a replica of "ProjectC(i) = entry"
ProjectA(i) looks like you are calling a function; ProjectA[i] looks like an array element.
I am coding a Ruby 1.9 script and I'm running into some issues using the .include? method with an array.
This is my whole code block:
planTypes = ['C','R','S'];
invalidPlan = true;
myPlan = '';
while invalidPlan do
print "Enter the plan type (C-Commercial, R-Residential, S-Student): ";
myPlan = gets().upcase;
if planTypes.include? myPlan
invalidPlan = false;
end
end
For troubleshooting purposes I added print statements:
while invalidPlan do
print "Enter the plan type (C-Commercial, R-Residential, S-Student): ";
myPlan = gets().upcase;
puts myPlan; # What is my input value? S
puts planTypes.include? myPlan # What is the boolean return? False
puts planTypes.include? "S" # What happens when hard coded? True
if planTypes.include? myPlan
puts "My plan is found!"; # Do I make it inside the if clause? Nope
invalidPlan = false;
end
end
Since I was getting the correct result with a hard-coded string, I tried "#{myPlan}" and myPlan.to_s. However I still get a false result.
I'm new to Ruby scripting, so I'm guessing I'm missing something obvious, but after reviewing similar question here and here, as well as checking the Ruby Doc, I'm at a loss as to way it's not acting correctly.
The result of gets includes a newline (\n), which you can see if you print myPlan.inspect:
Enter the plan type (C-Commercial, R-Residential, S-Student): C
"C\n"
Add strip to clean out the unwanted whitespace:
myPlan = gets().upcase.strip;
Enter the plan type (C-Commercial, R-Residential, S-Student): C
"C"
I want to use an expression like
#{ %$hashref{'key_name'}[1]
or
%$hashref{'key_name}->[1]
to get - and then test - the second (index = 1) member of an array (reference) held by my hash as its "key_name" 's value. But, I can not.
This code here is correct (it works), but I would have liked to combine the two lines that I have marked into one single, efficient, perl-elegant line.
foreach my $tag ('doit', 'source', 'dest' ) {
my $exists = exists( $$thisSectionConfig{$tag});
my #tempA = %$thisSectionConfig{$tag} ; #this line
my $non0len = (#tempA[1] =~ /\w+/ ); # and this line
if ( !$exists || !$non0len) {
print STDERR "No complete \"$tag\" ... etc ... \n";
# program exit ...
}
I know you (the general 'you') can elegantly combine these two lines. Could someone tell me how I could do this?
This code it testing a section of a config file that has been read into a $thisSectionConfig reference-to-a-hash by Config::Simple. Each config file key=value pair then is (I looked with datadumper) held as a two-member array: [0] is the key, [1] is the value. The $tag 's are configuration settings that must be present in the config file sections being processed by this code snippet.
Thank you for any help.
You should read about Arrow operator(->). I guess you want something like this:
foreach my $tag ('doit', 'source', 'dest') {
if(exists $thisSectionConfig -> {$tag}){
my $non0len = ($thisSectionConfig -> {$tag} -> [1] =~ /(\w+)/) ;
}
else {
print STDERR "No complete \"$tag\" ... etc ... \n";
# program exit ...
}
Some of you may notice I'm already back with the same painful code already. I'm not sure if the other question is still open or not once I accept an answer.
Now the problem is a little simpler. I found some code that checked for pangrams. It use to be def pangram?('sentence') but I needed line to go in there so I tried changing it to def pangram?(line). It doesn't seem to mesh well with my coding style and doesn't work. I tried to use .contain('a' . . 'z') to check for a pangram but someone I know tried that and it didn't work. Also google isn't much help either.
Any ideas for how I could check for pangrams in an if stmt?
# To change this template, choose Tools | Templates
# and open the template in the editor
# This program reads a file line by line,
#separating lines by writing into certain text files.
#PPQ - Pangrams, Palindromes, and Quotes
class PPQ
def pangram?(line)
unused_letters = ('a'..'z').to_a - line.downcase.chars.to_a
unused_letters.empty?
end
def categorize
file_pangram = File.new('pangram.txt', 'w')
file_palindrome = File.new('palindrome.txt', 'w')
file_quotes = File.new('quotes.txt','w')
File.open('ruby1.txt','r') do |file|
while line = file.gets
if(line.reverse == line)
file_palindrome.write line
elsif(pangram?(line)== true)
file_pangram.write line
else
file_quotes.write line
end
end
end
file.close
file_pangram.close
file_palindrome.close
file_quotes.close
end
end
my_ruby_assignment = PPQ.new
my_ruby_assignment.categorize
I'm partial to simpler syntax, something like
def pangram?(line)
('a'..'z').all? { |word| line.downcase.include? (word) }
end
if pangram?(line) then file_pangram.write line end
def pangram?(string)
str = string.chars.map(&:downcase)
letters =('a'..'z').to_a
result = true
letters.each do |l|
if !(str.include? l.downcase)
result = false
break
end
end
result
end
I'm trying to make a simple Vim script that would create very compact top-level folds for c files. Ideally, if it was run on this code:
static void funca(...)
{
...
}
/* Example comment */
static void funcb(...)
{
...
}
Then it would create folds which would look like this when closed:
+-- x Lines: static void funca(...)----------------------
+-- x Lines: static void funcb(...)----------------------
So basically it would be like foldmethod=syntax with foldlevel=1, except that each fold would start one line further up, and would extend further down to include all following blank lines.
I know how to make one of these folds (assuming foldmethod=manual):
/^{<cr>kVnn?^$<cr>zf
But I'm not sure how to put it into a function. This is my effort:
function Cfold()
set foldmethod=manual " Manual folds
ggzE " Delete all folds
while (/^{<cr>) " Somehow loop through each match
kVnn?^$<cr>zf " This would work fine except for the last function
endwhile
endfunction
map <Leader>f :call Cfold()<cr>
But it isn't valid, I'm not entirely sure how functions work. Also, it won't work for the last function in the file, since it won't find '^{' again. If someone could help me get this working, and somehow add a case for the last function in a file, I would be extremely grateful.
Thanks in advance :)
You can create folds programmatically using the foldexpr and foldtext. Try this, though you may have to tweak CFoldLevel so it doesn't swallow non-function parts of the code:
function! CFoldLevel(lnum)
let line = getline(a:lnum)
if line =~ '^/\*'
return '>1' " A new fold of level 1 starts here.
else
return '1' " This line has a foldlevel of 1.
endif
endfunction
function! CFoldText()
" Look through all of the folded text for the function signature.
let signature = ''
let i = v:foldstart
while signature == '' && i < v:foldend
let line = getline(i)
if line =~ '\w\+(.*)$'
let signature = line
endif
let i = i + 1
endwhile
" Return what the fold should show when folded.
return '+-- ' . (v:foldend - v:foldstart) . ' Lines: ' . signature . ' '
endfunction
function! CFold()
set foldenable
set foldlevel=0
set foldmethod=expr
set foldexpr=CFoldLevel(v:lnum)
set foldtext=CFoldText()
set foldnestmax=1
endfunction
See :help 'foldexpr' for more details.