57 lines
1.6 KiB
Ruby
57 lines
1.6 KiB
Ruby
require_relative "object"
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module Virtual
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# static description of a method
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# name
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# args (with defaults)
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# code
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# return arg (usually mystery, but for coded ones can be more specific)
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# known local variable names
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# temp variables (numbered)
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#
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class Method < Virtual::Object
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#return the main function (the top level) into which code is compiled
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def Method.main
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Method.new(:main , [] , Virtual::SelfReference )
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end
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def attributes
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[:name , :args , :receiver , :return_type , :start]
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end
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def initialize name , args , receiver = Virtual::SelfReference.new , return_type = Virtual::Mystery , start = MethodEnter.new
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@name = name.to_sym
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@args = args
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@locals = []
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@tmps = []
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@receiver = receiver
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@return_type = return_type
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@start = start
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@current = @start
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end
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attr_reader :name , :args , :receiver , :start
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attr_accessor :return_type
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def add instruction
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raise instruction.inspect unless instruction.is_a? Instruction
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@current.next = instruction
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@current = instruction
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end
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# determine whether this method has a variable by the given name
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# variables are locals and and arguments
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# used to determine if a send must be issued
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def has_var name
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var = @args.find {|a| a == name }
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var = @locals.find {|a| a == name } unless var
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var = @tmps.find {|a| a == name } unless var
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var
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end
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alias :get_var :has_var
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def get_tmp
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name = "__tmp__#{@tmps.length}"
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@tmps << name
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Ast::NameExpression.new(name)
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end
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end
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end
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