Programming Types
email Scott Turner
precise, logical types
| term | description | Python type | Python expressions* |
|---|---|---|---|
| primitive types | |||
| boolean | int | 1, 0, 1==0 | |
| integer | int,long | 0, 1, 2, -1 | |
| floating point | float | 2.718, -1.0 | |
| string | string | "3 is the best number!" | |
| none | trivial type with just 1 value | None | None |
| void | type with no values | None | mylist.append(123) |
| the indiscriminate type | input: function from string to action returning the indiscriminate type | ||
| derived types | |||
| tuple of | ("hello", "my", "name", "is", "Phil", "."): tuple of string (11, 16, 18, 50, 52): tuple of integer | ||
| list of | ["hello", "my", "name", "is", "Phil", "."]: list of string [11, 16, 18, 50, 52]: list of integer | ||
| function from to | string.atoi: function from string to integer car: for all t, function from list of t to t | ||
| action returning | put-newline: action returning the trivial type
random.choice: for all e, function from (list of e) to action returning e | ||
| and | subst: for all t, function from (t and t and (list of t)) to (list of t) | ||
| or | talky: function from the indiscriminate type to (boolean or the trivial type) | ||
| quantified types | |||
| for all type-parameter, | cons: for all t, function from (t and (list of t)) to (list of t) | ||