Execute a Markov algorithm: Difference between revisions
Content added Content deleted
mNo edit summary |
|||
| Line 19: | Line 19: | ||
raise "Syntax error: #{line}" |
raise "Syntax error: #{line}" |
||
end |
end |
||
end.compact |
|||
end.delete_if(&:nil?) |
|||
File.open(ARGV[2], "w") do |file| |
File.open(ARGV[2], "w") do |file| |
||
Revision as of 07:11, 15 December 2009
| This page uses content from Wikipedia. The original article was at Markov_algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) |
You are encouraged to solve this task according to the task description, using any language you may know.
Create an interpreter for a Markov Algorithm. Rules have the syntax:
<comment> ::= # {<any character>}
<rule> ::= <pattern> <whitespace> -> <whitespace> [.] <replacement>
<whitespace> ::= (<tab> | <space>) [<whitespace>]
There is one rule per line. If there is a . present before the <replacement>, then this is a terminating rule in which case the interpreter must halt execution.
Ruby
<lang Ruby>raise "Please input an input code file, an input data file, and an output file." if ARGV.size < 3
rules = File.readlines(ARGV[0]).map do |line|
if line =~ /^\s*#/
nil
elsif line =~ /^(.+)\s+->\s+(\.?)(.*)$/
[$1, $3, $2 != ""]
else
raise "Syntax error: #{line}"
end
end.compact
File.open(ARGV[2], "w") do |file|
file.write(File.read(ARGV[1]).tap { |input_data|
while rules.find { |match, replace, term|
if input_data[match]
input_data.sub!(match, replace)
break if term
true
else
false
end
}
end
})
end</lang>