Contents

# frozen_string_literal: true

# CSV Decision: CSV based Ruby decision tables.
# Created December 2017 by Brett Vickers
# See LICENSE and README.md for details.
module CSVDecision
  # Methods to assign a matcher to data cells
  module Matchers
    # rubocop: disable Lint/BooleanSymbol
    NON_NUMERIC_CONSTANTS = {
      true: true,
      false:  false,
      nil: nil
    }.freeze
    # rubocop: enable Lint/BooleanSymbol

    def self.input_cell_constant?(match)
      return false unless CELL_CONSTANT.member?(match['operator'])
      return false unless match['args'] == ''
      return false unless match['negate'] == ''

      name = match['name'].to_sym
      return false unless NON_NUMERIC_CONSTANTS.key?(name)

      Proc.with(type: :constant, function: NON_NUMERIC_CONSTANTS[name])
    end

    # Match cell against a function call or symbolic expression.
    class Function < Matcher
      # Looks like a function call or symbol expressions, e.g.,
      # == true
      # := function(arg: symbol)
      # == :column_name
      FUNCTION_CALL =
        "(?<operator>=|:=|==|<|>|!=|>=|<=|:|!\\s*:)\s*(?<negate>!?)\\s*(?<name>#{Header::COLUMN_NAME}|:)(?<args>.*)"
      FUNCTION_RE = Matchers.regexp(FUNCTION_CALL)

      # COMPARATORS = {
      #   '>'  => proc { |numeric_cell, value| Matchers.numeric(value) &.>  numeric_cell },
      #   '>=' => proc { |numeric_cell, value| Matchers.numeric(value) &.>= numeric_cell },
      #   '<'  => proc { |numeric_cell, value| Matchers.numeric(value) &.<  numeric_cell },
      #   '<=' => proc { |numeric_cell, value| Matchers.numeric(value) &.<= numeric_cell },
      #   '!=' => proc { |numeric_cell, value| Matchers.numeric(value) &.!= numeric_cell }
      # }.freeze

      def matches?(cell)
        match = FUNCTION_RE.match(cell)
        return false unless match

        # Check if the guard condition is a cell constant
        proc = Matchers.input_cell_constant?(match)
        return proc if proc

        false
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
csv_decision-0.0.3	lib/csv_decision/matchers/function.rb