Dictionaries

The following code examples demonstrate the built-in dictionary type offered by the language. See section [TBD] for details.

Type Declaration

Dict Name: {String: Int[-1]}.

Accessing

Containment

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];

some dict ("A"?) = true
some dict ("D"?) = false

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];

some dict ("A"?, "D"?) = {true, false}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];

some dict ("A" ? -1) = 0
some dict ("D" ? -1) = -1

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];

some dict("A" ? -1, "D" ? -1) = {0, -1}

some dict: {String: Int[0]} ["A"[1], "B"[2], "C"];
keys: {string}, {"A", "B", "C", "D"}

`Provide default for any key not found.`
some list: {Int*}, some dict (keys(...) ? -1);
some list = {1, 2, 0, -1}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];

some record: var, some dict(ValueA["A" ? -1], ValueD["D" ? -1]);
some record = {ValueA[1], ValueD[-1]}

Retrieving

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];
some dict ("C") = -1

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];
some dict !("C") = {"A"[0], "B"[1]}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];
some dict ("A", "C") = {0, -1}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];
some dict (ValueA["A"], ValueB["C"]) = {ValueA[0], ValueB[-1]}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"];
some dict (...) = {0, 1, -1}  // Total collection accessor.

Setting

some dict ("A") is 1,

some dict ("A", "B") is {1, 3},

Operators

Count

|some dict| = 5

|{"A"[0], "B"[1], "C"}| = 3

Difference (Remove Elements)

{"A"[0], "B"[1], "C"[2]} - {"A", "D"} = {"B"[1], "C"[2]}

{"A"[3], "B"[4], "C"[5]} - {"A"[0], "B"[1]} = {"C"[5]}

Equality

Setup

`Assume the following for all equality code examples.`

some dict: {Int: Int[-1]} [1[1], 2[1], 3[0]];

Approximate

some list: {Int*} [1, 2, 2, 3];
some dict ~ some list

some set: {Int} [1, 2, 3];
some dict ~ some set

Strict

some dict = {1[1], 2[1], 3[0]}

some dict = {1[1], 2[1], ...}  `Match remaining keys and their values.`

Intersection

{"A"[0], "B"[1], "C"[2]} % {"A", "D"} = {"A"[0]}

{"A"[3], "B"[4], "C"[5]} % {"A"[0], "B"[1]} = {"A"[3], "B"[4]}

{"A"[0], "B"[1], "C"[2]} % {"B", "A"} = {"A"[0], "B"[1]}

Union (Appending)

`Default int value is assigned to "D" through the union.`
{"A"[0], "B"[1], "C"[2]} + {"A", "D"} = {"A"[0], "B"[1], "C"[2]. "D"[0]}

some dict: {String: Int[-1]} ["A"[0], "B"[1], "C"[2]];
some dict + {"A", "D"} = {"A"[0], "B"[1], "C"[2]. "D"[-1]}

{"A"[0], "B"[1]} + {"A"[1], "C"[1]} = {"A"[0], "B"[1], "C"[1]}

Dict Name: {String: Int[-1]}.
{"A", "C"} as Dict Name + {"A"[0], "B"[1]} = {"A"[-1], "B"[1], "C"[-1]}