Creates an enumerator for each chunked elements. The beginnings of chunks are defined by pattern and the block.
If pattern === elt returns true or the block returns true for the element, the element is beginning of a chunk.
The === and block is called from the first element to the last element of enum. The result for the first element is ignored.
The result enumerator yields the chunked elements as an array. So each method can be called as follows:
enum.slice_before(pattern).each { |ary| ... }
enum.slice_before { |elt| bool }.each { |ary| ... }
Other methods of the Enumerator class and Enumerable module, such as to_a, map, etc., are also usable.
For example, iteration over ChangeLog entries can be implemented as follows:
# iterate over ChangeLog entries. open("ChangeLog") { |f| f.slice_before(/\A\S/).each { |e| pp e } } # same as above. block is used instead of pattern argument. open("ChangeLog") { |f| f.slice_before { |line| /\A\S/ === line }.each { |e| pp e } }
“svn proplist -R” produces multiline output for each file. They can be chunked as follows:
IO.popen([{"LC_ALL"=>"C"}, "svn", "proplist", "-R"]) { |f| f.lines.slice_before(/\AProp/).each { |lines| p lines } } #=> ["Properties on '.':\n", " svn:ignore\n", " svk:merge\n"] # ["Properties on 'goruby.c':\n", " svn:eol-style\n"] # ["Properties on 'complex.c':\n", " svn:mime-type\n", " svn:eol-style\n"] # ["Properties on 'regparse.c':\n", " svn:eol-style\n"] # ...
If the block needs to maintain state over multiple elements, local variables can be used. For example, three or more consecutive increasing numbers can be squashed as follows (see chunk_while for a better way):
a = [0, 2, 3, 4, 6, 7, 9] prev = a[0] p a.slice_before { |e| prev, prev2 = e, prev prev2 + 1 != e }.map { |es| es.length <= 2 ? es.join(",") : "#{es.first}-#{es.last}" }.join(",") #=> "0,2-4,6,7,9"
However local variables should be used carefully if the result enumerator is enumerated twice or more. The local variables should be initialized for each enumeration. Enumerator.new can be used to do it.
# Word wrapping. This assumes all characters have same width. def wordwrap(words, maxwidth) Enumerator.new {|y| # cols is initialized in Enumerator.new. cols = 0 words.slice_before { |w| cols += 1 if cols != 0 cols += w.length if maxwidth < cols cols = w.length true else false end }.each {|ws| y.yield ws } } end text = (1..20).to_a.join(" ") enum = wordwrap(text.split(/\s+/), 10) puts "-"*10 enum.each { |ws| puts ws.join(" ") } # first enumeration. puts "-"*10 enum.each { |ws| puts ws.join(" ") } # second enumeration generates same result as the first. puts "-"*10 #=> ---------- # 1 2 3 4 5 # 6 7 8 9 10 # 11 12 13 # 14 15 16 # 17 18 19 # 20 # ---------- # 1 2 3 4 5 # 6 7 8 9 10 # 11 12 13 # 14 15 16 # 17 18 19 # 20 # ----------
mbox contains series of mails which start with Unix From line. So each mail can be extracted by slice before Unix From line.
# parse mbox open("mbox") { |f| f.slice_before { |line| line.start_with? "From " }.each { |mail| unix_from = mail.shift i = mail.index("\n") header = mail[0...i] body = mail[(i+1)..-1] body.pop if body.last == "\n" fields = header.slice_before { |line| !" \t".include?(line[0]) }.to_a p unix_from pp fields pp body } } # split mails in mbox (slice before Unix From line after an empty line) open("mbox") { |f| emp = true f.slice_before { |line| prevemp = emp emp = line == "\n" prevemp && line.start_with?("From ") }.each { |mail| mail.pop if mail.last == "\n" pp mail } }
Returns a hash that contains filename as key and coverage array as value. This is the same as ‘Coverage.result(stop: false, clear: false)`.
{
"file.rb" => [1, 2, nil],
...
}
Generate a JSON document from the Ruby data structure obj and return it. The returned document is a prettier form of the document returned by unparse.
The opts argument can be used to configure the generator. See the generate method for a more detailed explanation.
Recursively calls passed Proc if the parsed data structure is an Array or Hash
Return consuming memory size of obj.
Note that the return size is incomplete. You need to deal with this information as only a HINT. Especially, the size of T_DATA may not be correct.
This method is only expected to work with C Ruby.
From Ruby 2.2, memsize_of(obj) returns a memory size includes sizeof(RVALUE).
Turns FIPS mode on or off. Turning on FIPS mode will obviously only have an effect for FIPS-capable installations of the OpenSSL library. Trying to do so otherwise will result in an error.
OpenSSL.fips_mode = true # turn FIPS mode on OpenSSL.fips_mode = false # and off again
Sets the list of characters that are word break characters, but should be left in text when it is passed to the completion function. Programs can use this to help determine what kind of completing to do. For instance, Bash sets this variable to “$@” so that it can complete shell variables and hostnames.
See GNU Readline’s rl_special_prefixes variable.
Raises NotImplementedError if the using readline library does not support.
Gets the list of characters that are word break characters, but should be left in text when it is passed to the completion function.
See GNU Readline’s rl_special_prefixes variable.
Raises NotImplementedError if the using readline library does not support.
If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2).
file_name can be an IO object.
File.world_readable?("/etc/passwd") #=> 420 m = File.world_readable?("/etc/passwd") sprintf("%o", m) #=> "644"
Returns true if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
Returns true if the named file is executable by the real user and group id of this process. See access(3).
Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.
Note that some OS-level security features may cause this to return true even though the file is not executable by the real user/group.
The mode needed to read a file as straight binary.
Safely read a file in binary mode on all platforms.
Looks for a gem dependency file at path and activates the gems in the file if found. If the file is not found an ArgumentError is raised.
If path is not given the RUBYGEMS_GEMDEPS environment variable is used, but if no file is found no exception is raised.
If ‘-’ is given for path RubyGems searches up from the current working directory for gem dependency files (gem.deps.rb, Gemfile, Isolate) and activates the gems in the first one found.
You can run this automatically when rubygems starts. To enable, set the RUBYGEMS_GEMDEPS environment variable to either the path of your gem dependencies file or “-” to auto-discover in parent directories.
NOTE: Enabling automatic discovery on multiuser systems can lead to execution of arbitrary code when used from directories outside your control.
Retrieves the server with the given uri.
See also regist_server and remove_server.
Returns whether or not macro is defined either in the common header files or within any headers you provide.
Any options you pass to opt are passed along to the compiler.
Returns whether or not the given entry point func can be found within lib. If func is nil, the main() entry point is used by default. If found, it adds the library to list of libraries to be used when linking your extension.
If headers are provided, it will include those header files as the header files it looks in when searching for func.
The real name of the library to be linked can be altered by --with-FOOlib configuration option.
Returns whether or not the function func can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the function name, in uppercase, prepended with HAVE_.
To check functions in an additional library, you need to check that library first using have_library(). The func shall be either mere function name or function name with arguments.
For example, if have_func('foo') returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.
Returns whether or not the variable var can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the variable name, in uppercase, prepended with HAVE_.
To check variables in an additional library, you need to check that library first using have_library().
For example, if have_var('foo') returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.
Returns whether or not the given header file can be found on your system. If found, a macro is passed as a preprocessor constant to the compiler using the header file name, in uppercase, prepended with HAVE_.
For example, if have_header('foo.h') returned true, then the HAVE_FOO_H preprocessor macro would be passed to the compiler.
Returns whether or not the given framework can be found on your system. If found, a macro is passed as a preprocessor constant to the compiler using the framework name, in uppercase, prepended with HAVE_FRAMEWORK_.
For example, if have_framework('Ruby') returned true, then the HAVE_FRAMEWORK_RUBY preprocessor macro would be passed to the compiler.
If fw is a pair of the framework name and its header file name that header file is checked, instead of the normally used header file which is named same as the framework.
Returns whether or not the static type type is defined. You may optionally pass additional headers to check against in addition to the common header files.
You may also pass additional flags to opt which are then passed along to the compiler.
If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with HAVE_TYPE_.
For example, if have_type('foo') returned true, then the HAVE_TYPE_FOO preprocessor macro would be passed to the compiler.