Class: Trxl::Calculator

Inherits:
Object
  • Object
show all
Extended by:
StdLib
Defined in:
lib/trxl/trxl.rb

Constant Summary

Constants included from StdLib

StdLib::AVG_HASH_RANGE_VALUE_SUM, StdLib::AVG_HASH_VALUE_SUM, StdLib::AVG_RANGE_SUM, StdLib::AVG_RANGE_SUM_OF_TYPE, StdLib::AVG_SUM_OF_TYPE, StdLib::DATES, StdLib::FOREACH_IN, StdLib::HASH_RANGE_VALUES, StdLib::HASH_RANGE_VALUE_SUM, StdLib::HASH_VALUES, StdLib::HASH_VALUE_SUM, StdLib::INJECT, StdLib::IN_GROUPS_OF, StdLib::MAP, StdLib::MONTH_FROM_DATE, StdLib::RATIO, StdLib::REJECT, StdLib::SELECT, StdLib::SUM_OF_TYPE, StdLib::TOTAL_RANGE_SUM_OF_TYPE, StdLib::YEAR_FROM_DATE

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Calculator

Returns a new instance of Calculator.



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# File 'lib/trxl/trxl.rb', line 590

def initialize
  @parser = TrxlParser.new
end

Class Method Details

.stdlib(function = nil) ⇒ Object 



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# File 'lib/trxl/trxl.rb', line 578

def stdlib(function = nil)
  if function
    Kernel.eval("Trxl::StdLib::#{function.to_s.upcase}").strip
  else
    Trxl::StdLib.constants.inject('') do |lib, const|
      lib << Kernel.eval("Trxl::StdLib::#{const}")
    end.strip
  end
end

Instance Method Details

#eval(expression, env = Environment.new, verbose = true, interpreter_mode = false) ⇒ Object

may raise eval an expression in calculations.treetop grammar eval an already parsed Treetop::Runtime::SyntaxNode



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# File 'lib/trxl/trxl.rb', line 627

def eval(expression, env = Environment.new, verbose = true, interpreter_mode = false)
  if expression.is_a?(Treetop::Runtime::SyntaxNode)
    interpreter_mode ? [ expression.eval(env), env ] : expression.eval(env)
  else
    ast = parse(expression, verbose)
    interpreter_mode ? [ ast.eval(env), env ] : ast.eval(env)
  end
end

#parse(code, verbose = true) ⇒ Object

may raise overwrite treetop to provide more precise exceptions



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# File 'lib/trxl/trxl.rb', line 596

def parse(code, verbose = true)
  if ast = @parser.parse(code)
    ast
  else
    failure_idx = @parser.failure_index

    # extract code snippet where parse error happened
    start = ((idx = failure_idx - 12) < 0 ? 0 : idx)
    stop  = ((idx = failure_idx + 12) > code.size ? code.size : idx)
    local_code = code.slice(start..stop).to_s.gsub(/\n|\r/, "")

    msg =  "Parse Error at index #{failure_idx} (showing excerpt):\n"
    msg << "... #{local_code} ...\n"

    # mark the exact offset where the parse error happened
    offset = (start == 0) ? failure_idx + 4 : 16
    offset.times { msg << ' '}; msg << "^\n"

    if verbose
      # show the originial trxl program
      msg << "Original Code:\n#{code}\n\n"
      # add detailed treetop parser error messages
      msg << @parser.failure_reason
    end
    raise(Trxl::FatalParseError, msg)
  end
end