Tables

Tables map hashable values to arbitrary objects. They are defined using double curly brackets, with -> mapping each key to each value:

tab: {{"key" -> "value", / -> [/\, "a"]}};

A table may be indexed by its keys, which will return their corresponding values, for example, from the previous table:

tab<<"key">> returns "value"
tab<</>> returns [2, "a"]

After its initialization, the items of a table can be set using this indexing syntax. If the key doesn't already exist in the table, it will be created.

tab<<"key">>: "newvalue" will overwrite the previous value of tab<<"key">>.

tab<<"newkey">>: //\ will create a new item in the table, with key "newkey" and value 6.

Tables can be merged together with the addition operator +. The values of the table to the right of the operator take priority when both tables share keys.

Items can be removed from a table by key using the subtraction operator -:

{{"a" -> /, "b" -> /\, // -> /\//}} - "b" gives {{"a" -> /, // -> /\//}}

Tables can be inverted using the unary ~ operator:

~{{"a" -> /, "b" -> /\}} gives {{/ -> "a", /\ -> "b"}}