1. Built in operators: +,-,*,/,%,==,!=,<=,>=,<,>,;
  1. Integers and floats in arithmetics: 1 or 2.33333 or 0.34 or .34
  1. Arbitrary nesting of parentheses: (1+2*(5+((3+4)3)-6/2)+72)\n => 61

  1. Comments:

    A comment until the end of the line

    /* A longer comment that spans multiple lines */

  1. Built in keywords: TRUE,FALSE,NULL,IF,ELSE,END
  1. Built in functions: HELP,ENV,SIZE,SPLIT,ROUND,MIN,MAX SUM,MULT,AVG, PRINT, PRINT_LINE TO_INT, TO_FLOAT, TO_ARRAY, AVG_SUM MATCHING_IDS, VALUES_OF_TYPE
  1. Standard library functions: foreach_in, inject, map, select reject, in_groups_of, sum_of_type avg_sum_of_type, avg_range_sum_of_type total_range_sum_of_type, ratio year_from_date, month_from_date, hash_values, hash_value_sum, avg_hash_value_sum, hash_range_values, hash_range_value_sum, avg_hash_range_value_sum
  1. Access the current environment: ENV; (your output may differ) => { :a => 3, :foo => 5 } Given the following environment: { :a => 1, :b => 2, :c => 3 } ENV => 1 ENV => { :a => 1, :b => 2 }
  1. Numeric variables and literals 3; => 3 a = 3; => 3 a; => 3
  1. String variables and literals "This is a string";
    => "This is a string"; 'This is a string'; => "This is a string"; s1 = "This is a string"; s1; => "This is a string" s2 = 'This is a string'; s2; => "This is a string" SIZE(s1); => 16 SIZE("foo"); => 3
  1. Variables and closure applications a = 3; foo = 5; calc = fun(x,y) { (x + y) * a + foo }; calc(2,2); => 17
  1. Array variables and literals arr = [1, [fun()2()], fun(x)x(3)] SIZE(arr); => 3 SIZE([1,2,3]); => 3 [1,2,3] + [4,[5,6]]; => [1,2,3,4,[5,6]] [1,2,3] - [[1],2,3]; => [1]
  1. Hash variables and literals h = { 1 => fun()2(), 'a' => 'foo' } SIZE(h); => 2 h; => 'fun()2()' h; => 'foo' SIZE({ 1 => 2}); => 1
  1. Range variables and literals range_including_upper = 1..5 => [ 1, 2, 3, 4, 5 ] SIZE(range_including_upper); => 5 range_excluding_upper = 1...5 => [ 1, 2, 3, 4 ] SIZE(range_excluding_upper); => 4 SIZE([1..5); => 5
  1. Conditional branching and recursion: factorial = fun(x) {
    if(x == 0) 1 else x * factorial(x - 1) end } factorial(5); => 120
  1. Conditional branching: foo = fun(x) { if(x == 0) 0 elsif(x == 1) 1 else 2 end } foo(0); => 0 foo(1); => 1 foo(2); => 2
  1. case expressions: foo = fun(x) { case x when NULL then NULL when 0 then 0 when 1 then 1 when 2 then 2 else
    3 end } foo(1); => 1 foo(3); => 3