Class: Cyc::SExpressionLexer

Inherits:
Object
  • Object
show all
Defined in:
lib/cyc/sexpr.rex.rb

Defined Under Namespace

Classes: ScanError

Instance Attribute Summary (collapse)

Instance Method Summary (collapse)

Instance Attribute Details

- (Object) filename (readonly)

Returns the value of attribute filename



14
15
16
# File 'lib/cyc/sexpr.rex.rb', line 14

def filename
  @filename
end

- (Object) lineno (readonly)

Returns the value of attribute lineno



13
14
15
# File 'lib/cyc/sexpr.rex.rb', line 13

def lineno
  @lineno
end

Instance Method Details

- (Object) action(&block)



18
19
20
# File 'lib/cyc/sexpr.rex.rb', line 18

def action &block
  yield
end

- (Object) do_parse

def scan_evaluate



139
140
# File 'lib/cyc/sexpr.rex.rb', line 139

def do_parse
end

- (Object) load_file(filename)



27
28
29
30
31
32
# File 'lib/cyc/sexpr.rex.rb', line 27

def load_file( filename )
  @filename = filename
  open(filename, "r") do |f|
    scan_evaluate  f.read
  end
end

- (Object) next_token



39
40
41
# File 'lib/cyc/sexpr.rex.rb', line 39

def next_token
  @rex_tokens.shift
end

- (Object) scan_evaluate(str)



43
44
45
46
47
48
49
50
51
52
53
54
55
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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
# File 'lib/cyc/sexpr.rex.rb', line 43

def scan_evaluate( str )
  scan_setup
  @rex_tokens = []
  @lineno  =  1
  ss = StringScanner.new(str)
  state = nil
  until ss.eos?
    text = ss.peek(1)
    @lineno  +=  1  if text == "\n"
    case state
    when nil
      case
      when (text = ss.scan(/\#<AS:/))
         @rex_tokens.push action { [:open_as,text] }

      when (text = ss.scan(/\#</))
         @rex_tokens.push action { [:open_quote,text] }

      when (text = ss.scan(/>/))
         @rex_tokens.push action { [:close_quote,text] }

      when (text = ss.scan(/\.\.\./))
         @rex_tokens.push action { [:continuation] }

      when (text = ss.scan(/\(/))
         @rex_tokens.push action { [:open_par,text] }

      when (text = ss.scan(/\)/))
         @rex_tokens.push action { [:close_par,text] }

      when (text = ss.scan(/NIL/))
         @rex_tokens.push action { [:nil,text] }

      when (text = ss.scan(/:[^<>\r\n\"\(\):&\?\#\ ]+/))
         @rex_tokens.push action { [:cyc_symbol,text] }

      when (text = ss.scan(/\?[^<>\r\n\"\(\):&\?\#\ ]+/))
         @rex_tokens.push action { [:variable,text] }

      when (text = ss.scan(/\#\$[a-zA-Z0-9:_-]+/))
         @rex_tokens.push action { [:term,text] }

      when (text = ss.scan(/[^\r\n\"\(\):&\ ]+/))
         @rex_tokens.push action { [:atom,text] }

      when (text = ss.scan(/\"/))
         @rex_tokens.push action { state = :STRING; @str = ""; [:in_string] }

      when (text = ss.scan(/:/))
         @rex_tokens.push action { [:assertion_sep]}

      when (text = ss.scan(/[\ \t\f\r\n]/))
        ;

      when (text = ss.scan(/.|\n/))
         @rex_tokens.push action { raise "Illegal character <#{text}>" }

      else
        text = ss.string[ss.pos .. -1]
        raise  ScanError, "can not match: '" + text + "'"
      end  # if

    when :STRING
      case
      when (text = ss.scan(/[^\n\r\"\\]+/))
         @rex_tokens.push action { @str << text; [:in_string]}

      when (text = ss.scan(/\t/))
         @rex_tokens.push action { @str << "\t"; [:in_string] }

      when (text = ss.scan(/\n/))
         @rex_tokens.push action { @str << "\n"; [:in_string] }

      when (text = ss.scan(/\r/))
         @rex_tokens.push action { @str << "\n"; [:in_string] }

      when (text = ss.scan(/\\"/))
         @rex_tokens.push action { @str << '"'; [:in_string] }

      when (text = ss.scan(/\\/))
         @rex_tokens.push action { @str << "\\"; [:in_string] }

      when (text = ss.scan(/\"/))
         @rex_tokens.push action { state = nil; [:string,@str] }

      else
        text = ss.string[ss.pos .. -1]
        raise  ScanError, "can not match: '" + text + "'"
      end  # if

    else
      raise  ScanError, "undefined state: '" + state.to_s + "'"
    end  # case state
  end  # until ss
end

- (Object) scan_file(filename)



34
35
36
37
# File 'lib/cyc/sexpr.rex.rb', line 34

def scan_file( filename )
  load_file  filename
  do_parse
end

- (Object) scan_setup



16
# File 'lib/cyc/sexpr.rex.rb', line 16

def scan_setup ; end

- (Object) scan_str(str)



22
23
24
25
# File 'lib/cyc/sexpr.rex.rb', line 22

def scan_str( str )
  scan_evaluate  str
  do_parse
end