Class: Parse::RockitProductionsEvaluator

Inherits:
Object
  • Object
show all
Defined in:
lib/rpdf2txt-rockit/rockit_grammar_ast_eval.rb

Instance Method Summary collapse

Constructor Details

#initialize(tokens = []) ⇒ RockitProductionsEvaluator 



120
121
122
123
 
# File 'lib/rpdf2txt-rockit/rockit_grammar_ast_eval.rb', line 120

def initialize(tokens = [])
  @token_map = Hash.new
  tokens.each {|token| @token_map[token.name] = token}
end

Instance Method Details

#eval_ast(ast) ⇒ Object 



125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
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
 
# File 'lib/rpdf2txt-rockit/rockit_grammar_ast_eval.rb', line 125

def eval_ast(ast)
  return nil unless ast
  case ast.name
  when "Productions"
  ast.productions.map {|prod| eval_ast(prod)}.flatten
  when "Prod"
  nonterminal = eval_ast(ast.nonterminal)
  ast.alts.map do |alt| 
    elements, treespec = eval_ast(alt)
    prod(nonterminal, elements, treespec)
  end
  when "Alt"
  [ast.elements.map {|e| eval_ast(e)}, 
    eval_ast(ast.astspec)]
  when "SymbolName"
  symbol = ast.lexeme
  @token_map[symbol] || symbol.intern
  when "ImplicitToken"
  eval(ast.regexp.lexeme) # Eval to String or Regexp
  when "Maybe"
  maybe(eval_ast(ast.element))
  when "Plus"
  plus(eval_ast(ast.element))
  when "Mult"
  mult(eval_ast(ast.element))
  when "Or"
  ore(*(ast.elements.map {|e| eval_ast(e)}))
  when "Sequence"
  ast.elements.map {|e| eval_ast(e)}
  when "List"
  liste(eval_ast(ast.element), eval_ast(ast.delimiter))
  when "AstSpec"
  if ast.elemspecs
    elemspecs = ast.elemspecs.map {|e| e.lexeme.intern}
  else
    elemspecs = []
  end
  if ast.prodspec
    prodspec = (ast.prodspec.lexeme == "^" ? :^ :eval_ast(ast.prodspec))
  else
    prodspec = nil
  end
  stb(prodspec, elemspecs)
  when "Lift"
  :^
  end
end