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



16
17
18
 
# 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 



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
 
# 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 



97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
 
# 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



24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# 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 



84
85
86
87
88
89
90
91
92
93
94
95
 
# 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 



17
18
19
20
21
22
 
# 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 



20
21
22
 
# File 'lib/tabreader/version.rb', line 20

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

.version ⇒ Object 



12
13
14
 
# File 'lib/tabreader/version.rb', line 12

def self.version
  VERSION
end