50 lines
1.3 KiB
Ruby
50 lines
1.3 KiB
Ruby
module Imbecile
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class Grammar
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# @return [String, nil] Module name.
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attr_reader :modulename
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# @return [String, nil] Class name.
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attr_reader :classname
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def initialize
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@tokens = {}
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@rules = {}
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end
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# @return [Boolean]
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# Whether loading was successful.
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def load(input_file)
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File.read(input_file).each_line.each_with_index do |line, line_index|
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line = line.chomp
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line_number = line_index + 1
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if line =~ /^\s*#/
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# Skip comment lines.
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elsif line =~ /^\s*$/
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# Skip blank lines.
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elsif line =~ /^\s*module\s+(\S+)$/
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@modulename = $1
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elsif line =~ /^\s*class\s+(\S+)$/
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@classname = $1
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elsif line =~ /^\s*token\s+(\S+)\s+(.*)$/
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name, expr = $1, $2
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unless name =~ /^[a-zA-Z_][a-zA-Z_0-9]*$/
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$stderr.puts "Invalid token name #{name} on line #{line_number}"
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return false
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end
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if @tokens[name]
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$stderr.puts "Duplicate token name #{name} on line #{line_number}"
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return false
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end
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@tokens[name] = expr
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else
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$stderr.puts "Unexpected input on line #{line_number}: #{line}"
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return false
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end
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end
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true
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end
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end
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end
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