Class: TabReader

Inherits:
Object
  • Object
show all
Defined in:
lib/tabreader/version.rb,
lib/tabreader/reader.rb

Overview

note: for now TabReader is a class!!! NOT a module - change - why? why not?

Constant Summary collapse

MAJOR =

todo: namespace inside version or something - why? why not??

0
MINOR = 
1
PATCH = 
0
VERSION = 
[MAJOR,MINOR,PATCH].join('.')

Class Method Summary collapse

Class Method Details



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# File 'lib/tabreader/version.rb', line 16

def self.banner
  "tabreader/#{VERSION} on Ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}) [#{RUBY_PLATFORM}]"
end

.foreach(path, headers: false) ⇒ Object 



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# File 'lib/tabreader/reader.rb', line 56

def self.foreach( path, headers: false )
  if headers.is_a?( Array )
    columns = headers
  else
    columns = nil    ## header row a.k.a. columns / fields
  end

	File.open( path, 'r:utf-8' ).each_line do |line|
		pp line
		values = parse_line( line )
		if headers  ## add values as name/value pairs e.g. array of hashes
			if columns.nil?
				columns = values    ## first row is header row
			else
				pairs = columns.zip(values)
				h = pairs.to_h
				yield( h )
			end
		else       ## add values as is e.g. array of array
			yield( values )
		end
	end

	# return nil
	nil
end

.header(path) ⇒ Object 



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# File 'lib/tabreader/reader.rb', line 97

def self.header( path )
  line =  File.open( path, 'r:utf-8' ) do |f|
     if f.eof?
			 ## handle empty file; return empty string; no readline call possible
			 ##  todo/check: return nil from header is no header or [] - why? why not?
			 ##   or throw exception  end of file reached (EOFError) - why? why not?
			  ""
		 else
			 f.readline
		 end
  end

  ## note: line includes \n or \r\n at the end
  ## pp line
  parse_line( line )
end

.parse(txt, headers: false) ⇒ Object

use parse_rows or parse_lines for array or array results



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# File 'lib/tabreader/reader.rb', line 24

def self.parse( txt, headers: false )   ## use parse_rows or parse_lines for array or array results
   rows = []

   if headers.is_a?( Array )
     columns = headers
   else
     columns = nil    ## header row a.k.a. columns / fields
   end

   txt.each_line do |line|
     values = parse_line( line )
     if headers  ## add values as name/value pairs e.g. array of hashes
       if columns.nil?
         columns = values    ## first row is header row
       else
         ## note: will cut-off values if values.size > columns.size
         ##   add warning/error - why? why not?
         ##  if values.size <= columns.size will get filled-up with nil
         pairs = columns.zip(values)
         ## pp pairs
         h = pairs.to_h
         ## pp h

         rows << h
       end
     else       ## add values as is e.g. array of array
       rows << values
     end
   end
   rows
end

.parse_line(line) ⇒ Object 



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# File 'lib/tabreader/reader.rb', line 84

def self.parse_line( line )
  ## check - can handle comments and blank lines too - why? why not?
  ## remove trailing newlines

  ##  note: chomp('') if is an empty string,
  ##    it will remove all trailing newlines from the string.
	##    use line.sub(/[\n\r]*$/, '') or similar instead - why? why not?
  line = line.chomp('')

  values = line.split("\t")
  values
end

.read(path, headers: false) ⇒ Object 



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# File 'lib/tabreader/reader.rb', line 17

def self.read( path, headers: false )
  txt = File.open( path, 'r:utf-8' ).read
	## puts "#{path}:"
  ## pp txt
  parse( txt, headers: headers )
end

.root ⇒ Object 



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# File 'lib/tabreader/version.rb', line 20

def self.root
  File.expand_path( File.dirname(File.dirname(File.dirname(__FILE__))) )
end

.version ⇒ Object 



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# File 'lib/tabreader/version.rb', line 12

def self.version
  VERSION
end