Comma quibbling: Difference between revisions
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{ABC and DEF} |
{ABC and DEF} |
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{ABC, DEF, G and H}</pre> |
{ABC, DEF, G and H}</pre> |
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=={{header|Perl 6}}== |
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<lang perl6>sub comma-quibbling(@A) { |
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'{' ~ ( |
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@$_ < 3 ?? .join(',') !! |
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.[0..*-2].join(',') ~ ' and ' ~ .[*-1] |
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) ~ '}' given @A».perl |
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} |
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say comma-quibbling(eval($_)) for |
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< [] ["ABC"] ["ABC","DEF"] ["ABC","DEF","G","H"] >;</lang> |
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{{out}} |
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<pre>{} |
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{"ABC"} |
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{"ABC","DEF"} |
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{"ABC","DEF","G" and "H"}</pre> |
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=={{header|Python}}== |
=={{header|Python}}== |
Revision as of 09:42, 6 October 2013
Comma quibbling is a task originally set by Eric Lippert in his blog.
The task is to write a function to generate a string output which is the concatenation of input words from a list/sequence where:
- An input of no words produces the output string of just the two brace characters "{}".
- An input of just one word, e.g. ["ABC"], produces the output string of the word inside the two braces, e.g. "{ABC}".
- An input of two words, e.g. ["ABC", "DEF"], produces the output string of the two words inside the two braces with the words separated by the string " and ", e.g. "{ABC and DEF}".
- An input of three or more words, e.g. ["ABC", "DEF", "G", "H"], produces the output string of all but the last word separated by ", " with the last word separated by " and " and all within braces; e.g. "{ABC, DEF, G and H}".
Test your function with the following series of inputs showing your output here on this page:
- [] # (No input words).
- ["ABC"]
- ["ABC", "DEF"]
- ["ABC", "DEF", "G", "H"]
Note: for this task assume words are non-empty strings.
D
<lang d>import std.stdio, std.string;
string quibbler(in string[] seq) pure /*nothrow*/ {
if (seq.length <= 1) return format("{%-(%s, %)}", seq); else return format("{%-(%s, %) and %s}", seq[0 .. $-1], seq[$-1]);
}
void main() {
//foreach (immutable test; [[], foreach (const test; [[], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]]) test.quibbler.writeln;
}</lang>
- Output:
{} {ABC} {ABC and DEF} {ABC, DEF, G and H}
Perl 6
<lang perl6>sub comma-quibbling(@A) {
'{' ~ ( @$_ < 3 ?? .join(',') !! .[0..*-2].join(',') ~ ' and ' ~ .[*-1] ) ~ '}' given @A».perl
}
say comma-quibbling(eval($_)) for < [] ["ABC"] ["ABC","DEF"] ["ABC","DEF","G","H"] >;</lang>
- Output:
{} {"ABC"} {"ABC","DEF"} {"ABC","DEF","G" and "H"}
Python
<lang python>>>> def strcat(sequence): # replace(..) can only replace the first X occurrences not the last # Hence the replace is done on the reverse of the intermediate string # then reversed back. return '{%s}' % ', '.join(sequence)[::-1].replace(',', 'dna ', 1)[::-1]
>>> for seq in ([], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]): print('Input: %-24r -> Output: %r' % (seq, strcat(seq)))
Input: [] -> Output: '{}'
Input: ['ABC'] -> Output: '{ABC}'
Input: ['ABC', 'DEF'] -> Output: '{ABC and DEF}'
Input: ['ABC', 'DEF', 'G', 'H'] -> Output: '{ABC, DEF, G and H}'
>>> </lang>