class Predicator::Evaluator
Attributes
context[R]
instructions[R]
stack[R]
Public Class Methods
new(instructions, context_data={})
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# File lib/predicator/evaluator.rb, line 7 def initialize instructions, context_data={} @instructions = instructions @context = context_for context_data @stack = [] @ip = 0 end
Public Instance Methods
blank?(val)
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# File lib/predicator/evaluator.rb, line 77 def blank? val val.respond_to?(:empty?) ? !!val.empty? : !val end
compare(comparison)
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# File lib/predicator/evaluator.rb, line 99 def compare comparison right = stack.pop left = stack.pop if left.nil? || right.nil? stack.push false else stack.push send("compare_#{comparison}", left, right) end rescue StandardError stack.push false end
compare_BETWEEN()
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# File lib/predicator/evaluator.rb, line 139 def compare_BETWEEN max = stack.pop min = stack.pop val = stack.pop if max.nil? || min.nil? || val.nil? stack.push false else result = val.between? min, max stack.push result end rescue StandardError stack.push false end
compare_ENDSWITH(left, right)
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# File lib/predicator/evaluator.rb, line 135 def compare_ENDSWITH left, right left.end_with? right end
compare_EQ(left, right)
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# File lib/predicator/evaluator.rb, line 111 def compare_EQ left, right left == right end
compare_GT(left, right)
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# File lib/predicator/evaluator.rb, line 115 def compare_GT left, right left > right end
compare_IN(left, right)
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# File lib/predicator/evaluator.rb, line 123 def compare_IN left, right right.include? left end
compare_LT(left, right)
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# File lib/predicator/evaluator.rb, line 119 def compare_LT left, right left < right end
compare_NOTIN(left, right)
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# File lib/predicator/evaluator.rb, line 127 def compare_NOTIN left, right !right.include? left end
compare_STARTSWITH(left, right)
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# File lib/predicator/evaluator.rb, line 131 def compare_STARTSWITH left, right left.start_with? right end
context_for(context_data)
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# File lib/predicator/evaluator.rb, line 14 def context_for context_data return context_data unless context_data.kind_of? Hash Context.new context_data end
date_ago(seconds)
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# File lib/predicator/evaluator.rb, line 67 def date_ago seconds past_time = Time.now - seconds to_date past_time.strftime "%Y-%m-%d" end
date_from_now(seconds)
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# File lib/predicator/evaluator.rb, line 72 def date_from_now seconds future_time = Time.now + seconds to_date future_time.strftime "%Y-%m-%d" end
jump_if_false(offset)
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# File lib/predicator/evaluator.rb, line 81 def jump_if_false offset if stack[-1] == false adjusted_offset = offset - 1 @ip += adjusted_offset else stack.pop end end
jump_if_true(offset)
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# File lib/predicator/evaluator.rb, line 90 def jump_if_true offset if stack[-1] == true adjusted_offset = offset - 1 @ip += adjusted_offset else stack.pop end end
process(instruction)
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# File lib/predicator/evaluator.rb, line 27 def process instruction case instruction.first when "not" then stack.push !stack.pop when "jfalse" then jump_if_false instruction.last when "jtrue" then jump_if_true instruction.last when "lit", "array" then stack.push instruction.last when "load" then stack.push context[instruction.last] when "to_bool" then stack.push !!stack.pop when "to_int" then stack.push to_int(stack.pop) when "to_str" then stack.push to_str(stack.pop) when "to_date" then stack.push to_date(stack.pop) when "date_ago" then stack.push date_ago(stack.pop) when "date_from_now" then stack.push date_from_now(stack.pop) when "blank" then stack.push blank?(stack.pop) when "present" then stack.push !blank?(stack.pop) when "compare" if instruction.last == "BETWEEN" compare_BETWEEN else compare instruction.last end end end
result()
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# File lib/predicator/evaluator.rb, line 19 def result while @ip < instructions.length process @instructions[@ip] @ip += 1 end stack.pop end
to_date(val)
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# File lib/predicator/evaluator.rb, line 63 def to_date val val.nil? ? nil : Date.parse(val) end
to_int(val)
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# File lib/predicator/evaluator.rb, line 51 def to_int val if val.nil? || (val.is_a?(String) && val.empty?) nil else val.to_i end end
to_str(val)
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# File lib/predicator/evaluator.rb, line 59 def to_str val val.nil? ? nil : val.to_s end