59 lines
1.9 KiB
Ruby
59 lines
1.9 KiB
Ruby
module Ast
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class FunctionExpression < Expression
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attr_reader :name, :params, :body
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def initialize name, params, body
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@name, @params, @body = name.to_sym, params, body
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end
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def attributes
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[:name, :params, :body]
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end
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def inspect
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self.class.name + ".new(" + name.inspect + ", ["+
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params.collect{|m| m.inspect }.join( ",") +"] , [" +
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body.collect{|m| m.inspect }.join( ",") +"] )"
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end
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def to_s
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"def #{name}( " + params.join(",") + ") \n" + body.join("\n") + "end\n"
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end
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def compile context , into
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raise "function does not compile into anything #{self}" if into
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args = []
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locals = {}
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params.each_with_index do |param , index|
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arg = param.name
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arg_value = Vm::Integer.new(index+1)
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locals[arg] = arg_value
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args << arg_value
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end
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function = Vm::Function.new(name , args )
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context.current_class.add_function function
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parent_locals = context.locals
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parent_function = context.function
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context.locals = locals
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context.function = function
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into = function.body
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last_compiled = nil
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body.each do |b|
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last_compiled = b.compile(context , into)
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puts "compiled in function #{last_compiled.inspect}"
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raise "alarm #{last_compiled} \n #{b}" unless last_compiled.is_a? Vm::Word
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end
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return_reg = Vm::Integer.new(7)
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if last_compiled.is_a?(Vm::IntegerConstant) or last_compiled.is_a?(Vm::StringConstant)
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return_reg.load into , last_compiled if last_compiled.register != return_reg.register
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else
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return_reg.move( into, last_compiled ) if last_compiled.register != return_reg.register
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end
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function.set_return return_reg
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context.locals = parent_locals
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context.function = parent_function
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function
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end
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end
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end |