Module: Pdfrb::Arlington::Predicate::Functions::ArithmeticPredicates

Defined in:
lib/pdfrb/arlington/predicate/functions/arithmetic.rb

Overview

Arithmetic helpers: ArrayLength, StringLength, RequiredValue, BitSet, BitsClear, BitsSet, KeyNameIsColorant.

Class Method Summary collapse

Class Method Details

.register_all ⇒ Object 



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# File 'lib/pdfrb/arlington/predicate/functions/arithmetic.rb', line 12

def register_all
  Functions.register("ArrayLength") do |args, ctx|
    key = args.first
    val = ctx.current && ctx.current[key.to_sym]
    val = val.to_a if val.is_a?(Pdfrb::Model::PdfArray)
    val.is_a?(::Array) ? val.length : 0
  end

  Functions.register("StringLength") do |args, ctx|
    key = args.first
    val = ctx.current && ctx.current[key.to_sym]
    val.is_a?(::String) ? val.bytesize : 0
  end

  Functions.register("RequiredValue") do |_args, _ctx|
    # Caller wraps as RequiredValue(@X == Y); the comparison
    # happens in BinOp, this just passes through.
    true
  end

  Functions.register("BitSet") do |args, _ctx|
    value, bit = args
    next false unless value.is_a?(::Integer) && bit.is_a?(::Integer)

    (value & (1 << bit)).nonzero?
  end

  Functions.register("BitsClear") do |args, _ctx|
    value, mask = args
    next false unless value.is_a?(::Integer) && mask.is_a?(::Integer)

    (value & mask).zero?
  end

  Functions.register("BitsSet") do |args, _ctx|
    value, mask = args
    next false unless value.is_a?(::Integer) && mask.is_a?(::Integer)

    (value & mask) == mask
  end

  Functions.register("KeyNameIsColorant") do |_args, _ctx|
    false # consumer-side; default to false
  end

  Functions.register("NoCycle") do |_args, _ctx|
    true # consumer-side; assume no cycles until proven
  end
end