# Box - monad <

< Help(Redirected from Help/Primer/Box - monad lt)

Jump to navigation
Jump to search
So far you have dealt with atoms that are either numeric or character. The monad < (box) introduces a new type of atom called boxed. The monad < applies to any noun and returns an atom that is a box which contains the argument.

An array is either a numeric array that contains numbers, or a literal array that contains characters, or a boxed array that contains boxes. Arrays of numbers and characters are referred to as open to distinguish them from boxed arrays.

b =. < 2 3 4 $b NB. an atom has empty shape

A boxed array is displayed in a box.

b +-----+ |2 3 4| +-----+ c =. < 4 7 9 d =. b , c NB. append d +-----+-----+ |2 3 4|4 7 9| +-----+-----+ $d NB. list with shape 2 2 (< 2 3 4) , < 4 7 9 +-----+-----+ |2 3 4|4 7 9| +-----+-----+

Arrays of different types (numeric, character, and boxed) cannot be appended to one another.

'a' , 3 |domain error, executing dyad , |arguments are incompatible: character and numeric | 'a' ,3 3 , < 2 3 4 |domain error, executing dyad , |arguments are incompatible: character and boxed | 'a' ,<2 3 4

Boxed arrays are of the same type and can be appended no matter what they contain.

(< 'abc') , < 4 5 6 +---+-----+ |abc|4 5 6| +---+-----+ (< 2 3 $ 'abcdef') , (< i. 3 4) , < 23 +---+---------+--+ |abc|0 1 2 3|23| |def|4 5 6 7| | | |8 9 10 11| | +---+---------+--+

Primer Index Hover to reveal titles - Click to access - Current page is highlighted | ||||||||||||||||||||||||

1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | ✅ |

26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | ✅ | ||||||

45 | 46 | 47 | 48 | ✅ | ||||||||||||||||||||

50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | ✅ | ||||||||||||||||

59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | ✅ | |||||||

77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | ✅ | |||||

97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | ✅ |