Class: Lisp::Parser

Inherits:
Object show all
Defined in:
lib/rubylisp/parser.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Parser

Returns a new instance of Parser.



5
6
 
# File 'lib/rubylisp/parser.rb', line 5

def initialize
end

Instance Method Details

#make_character(ch) ⇒ Object 



28
29
30
 
# File 'lib/rubylisp/parser.rb', line 28

def make_character(ch)
  Lisp::Character.with_value(ch)
end

#make_float(str) ⇒ Object 



16
17
18
 
# File 'lib/rubylisp/parser.rb', line 16

def make_float(str)
  Lisp::Number.with_value(str.to_f)
end

#make_hex_number(str) ⇒ Object 



12
13
14
 
# File 'lib/rubylisp/parser.rb', line 12

def make_hex_number(str)
  Lisp::Number.with_value(["0x", str].join.to_i(0))
end

#make_number(str) ⇒ Object 



8
9
10
 
# File 'lib/rubylisp/parser.rb', line 8

def make_number(str)
  Lisp::Number.with_value(str.to_i)
end

#make_string(str) ⇒ Object 



20
21
22
 
# File 'lib/rubylisp/parser.rb', line 20

def make_string(str)
  Lisp::String.with_value(str)
end

#make_symbol(str) ⇒ Object 



24
25
26
 
# File 'lib/rubylisp/parser.rb', line 24

def make_symbol(str)
  Lisp::Symbol.named(str)
end

#parse(src) ⇒ Object 



248
249
250
251
 
# File 'lib/rubylisp/parser.rb', line 248

def parse(src)
  tokenizer = Tokenizer.from_string(src)
  self.parse_sexpr(tokenizer)
end

#parse_and_eval(src, env = Lisp::EnvironmentFrame.global) ⇒ Object 



259
260
261
262
 
# File 'lib/rubylisp/parser.rb', line 259

def parse_and_eval(src, env=Lisp::EnvironmentFrame.global)
  sexpr = self.parse(src)
  return sexpr.evaluate(env)
end

#parse_and_eval_all(src, env = Lisp::EnvironmentFrame.global) ⇒ Object 



264
265
266
267
268
269
270
271
272
 
# File 'lib/rubylisp/parser.rb', line 264

def parse_and_eval_all(src, env=Lisp::EnvironmentFrame.global)
  tokenizer = Tokenizer.from_string(src)
  result = nil
  until tokenizer.eof?
    sexpr = self.parse_sexpr(tokenizer)
    result = sexpr.evaluate(env)
  end
  result
end

#parse_cons_cell(start_pos, tokens) ⇒ Object 



32
33
34
35
36
37
38
39
40
41
42
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
 
# File 'lib/rubylisp/parser.rb', line 32

def parse_cons_cell(start_pos, tokens)
  pos, tok, lit = tokens.next_token
  if tok == :RPAREN
    tokens.consume_token
    return Lisp::ConsCell.cons().tap do |obj|
      obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
    end
  end

  car = nil
  cdr = nil
  cells = []
  while tok != :RPAREN
    if tok == :PERIOD
      tokens.consume_token
      cdr = self.parse_sexpr(tokens)
      return nil if tokens.next_token[0] == :EOF
      pos, tok, lit = tokens.next_token
      return Lisp::Debug.process_error("Expected ')' to follow a dotted tail on line #{tokens.line_number}", Lisp::EnvironmentFrame.global) if tok != :RPAREN
      tokens.consume_token
      return Lisp::ConsCell.array_to_list(cells, cdr).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    else
      car = self.parse_sexpr(tokens)
      return Lisp::Debug.process_error("Unexpected EOF (expected ')') on line #{tokens.line_number}", Lisp::EnvironmentFrame.global) if tokens.next_token[0] == :EOF
      cells << car
    end
    pos, tok, lit = tokens.next_token
  end

  tokens.consume_token
  Lisp::ConsCell.array_to_list(cells).tap do |obj|
    obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
  end
end

#parse_frame(start_pos, tokens, literal) ⇒ Object 



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
 
# File 'lib/rubylisp/parser.rb', line 69

def parse_frame(start_pos, tokens, literal)
  m = {}
  pos, tok, lit = tokens.next_token
  if tok == :RBRACE
    tokens.consume_token
    if literal
      Lisp::Frame.new.tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    else
      Lisp::ConsCell.cons(Lisp::Symbol.named("make-frame"), nil).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    end
  else
    cells = []
    while tok != :RBRACE
      item = self.parse_sexpr(tokens)
      return Lisp::Debug.process_error("Unexpected EOF (expected '}') on line #{tokens.line_number}", env) if tokens.next_token[0] == :EOF
      cells << item
      pos, tok, lit = tokens.next_token
    end
    
    tokens.consume_token
    keys_and_values = Lisp::ConsCell.array_to_list(cells)
    if literal
      Lisp::PrimFrame.make_frame_impl(keys_and_values, Lisp::EnvironmentFrame.global).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    else
      Lisp::ConsCell.cons(Lisp::Symbol.named("make-frame"), keys_and_values).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    end
  end
end

#parse_object_from_file(port, env = Lisp::EnvironmentFrame.global) ⇒ Object 



253
254
255
256
257
 
# File 'lib/rubylisp/parser.rb', line 253

def parse_object_from_file(port, env=Lisp::EnvironmentFrame.global)
  tokenizer = Tokenizer.from_file(port)
  result = self.parse_sexpr(tokenizer)
  result.nil? ? Lisp::EofObject.instance : result
end

#parse_sexpr(tokens) ⇒ Object 



145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
 
# File 'lib/rubylisp/parser.rb', line 145

def parse_sexpr(tokens)
  while true
    pos, tok, lit = tokens.next_token
    # puts "token: <#{tok}, #{lit}>"
    return nil if tok == :EOF
    tokens.consume_token
    case tok
    when :COMMENT
      next
    when :NUMBER
      return make_number(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :FLOAT
      return make_float(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :HEXNUMBER
      return make_hex_number(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :STRING
      return make_string(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :CHARACTER
      return make_character(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :LPAREN
      return parse_cons_cell(pos, tokens)
    when :LBRACE
      return parse_frame(pos, tokens, false)
    when :QUOTE_LBRACE
      return parse_frame(pos, tokens, true)
    when :HASH_LPAREN
      return parse_vector(pos, tokens, false)
    when :QUOTE_HASH_LPAREN
      return parse_vector(pos, tokens, true)
    when :SYMBOL
      return make_symbol(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :FFI_NEW_SYMBOL
      return Lisp::FfiNew.new(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :FFI_SEND_SYMBOL
      return Lisp::FfiSend.new(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :FFI_STATIC_SYMBOL
      return Lisp::FfiStatic.new(lit).tap do |obj|
    obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    when :FALSE
      if @parse_for_debugging
        return Lisp::Boolean.with_value(false).tap do |obj|
          obj.set_location(pos, 2) if @parse_for_debugging
        end
      else
        return Lisp::FALSE
      end
    when :TRUE
      if @parse_for_debugging
        return Lisp::Boolean.with_value(false).tap do |obj|
          obj.set_location(pos, 2) if @parse_for_debugging
        end
      else
        return Lisp::TRUE
      end
    when :QUOTE
      expr = parse_sexpr(tokens)
      return Lisp::ConsCell.array_to_list([Lisp::Symbol.named('quote'), expr]).tap do |obj|
        obj.set_location(pos, expr.src_length + 1) if @parse_for_debugging
      end
    when :BACKQUOTE
      expr = parse_sexpr(tokens)
      return Lisp::ConsCell.array_to_list([Lisp::Symbol.named('quasiquote'), expr]).tap do |obj|
        obj.set_location(pos, expr.src_length + 1) if @parse_for_debugging
      end
    when :COMMA
      expr = parse_sexpr(tokens)
      return Lisp::ConsCell.array_to_list([Lisp::Symbol.named('unquote'), expr]).tap do |obj|
        obj.set_location(pos, expr.src_length + 1) if @parse_for_debugging
      end
    when :COMMAAT
      expr = parse_sexpr(tokens)
      return Lisp::ConsCell.array_to_list([Lisp::Symbol.named('unquote-splicing'), expr]).tap do |obj|
        obj.set_location(pos, expr.src_length + 2) if @parse_for_debugging
      end
    when :WHITESPACE
      next
    when :ILLEGAL
      return Lisp::Debug.process_error("Illegal token: #{lit} on line #{tokens.line_number}", Lisp::EnvironmentFrame.global)
    else
      return make_symbol(lit).tap do |obj|
        obj.set_location(pos, lit.length) if @parse_for_debugging
      end
    end
  end
end

#parse_vector(start_pos, tokens, literal) ⇒ Object 



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
138
139
140
141
142
 
# File 'lib/rubylisp/parser.rb', line 107

def parse_vector(start_pos, tokens, literal)
  v = []
  pos, tok, lit = tokens.next_token
  if tok == :RPAREN
    tokens.consume_token
    if literal
      Lisp::Vector.new.tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    else
      Lisp::ConsCell.cons(Lis::Symbol.named("vector"), nil).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    end
  else
    cells = []
    while tok != :RPAREN
      item = self.parse_sexpr(tokens)
      return Lisp::Debug.process_error("Unexpected EOF (expected ')') on line #{tokens.line_number}", env) if tokens.next_token[0] == :EOF
      cells << item
      pos, tok, lit = tokens.next_token
    end
    
    tokens.consume_token
    
    if literal
      Lisp::Vector.with_array(cells).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    else
      Lisp::ConsCell.cons(Lisp::Symbol.named("vector"), Lisp::ConsCell.array_to_list(cells)).tap do |obj|
        obj.set_location(start_pos, pos - start_pos + 1) if @parse_for_debugging
      end
    end
  end
end

#process_file(fname) ⇒ Object 



274
275
276
277
278
 
# File 'lib/rubylisp/parser.rb', line 274

def process_file(fname)
  File.open(fname) do |f|
    parse_and_eval_all(f.read)
  end
end