Standard Library
The following routines, operators and contracts are provided as part of the standard library.
Primitive Contracts#
Quarrel is a gradually-typed language which means there is no need to specify what type of data you are using but you can add contracts on a per-data basis where needed. Quarrel provides several builtin primitive contracts for all of the builtin literals and some auxiliary ones as well.
Numeric#
When you use a number literal, Quarrel will store it as an integer if no decimal point, a decimal if there is one, and one of the radix-types if the radix operator ^^ is used. You can also use ^ to indicate scientifix notation (followed by the degree) for any of the numeric literals.
Text#
Texts are special lists of graphemes (or characters). The literal form uses the " operator (the ' operator is for symbol literals).
Date/Time#
Quarrel uniquely contains a literal type for dates and times. They are a very common type of data and to avoid additional word-based namespaces and routes, Quarrel has opted for something more builtin to the syntax. Dates can be identified by having a base specified as [8601]^^ followed by a special date/time formatted literal. This format is known as ISO 8601 and Quarrel supports nearly all of the different representations within the ISO format.
Custom Literals
Quarrel plans to support other formats using [x]^^ format in the future. You can also add your own by adding a name and a regular expression. The only limitation is no spaces are allowed. The code fails on the use of \s and ignores actual spaces.
Truth Value#
In Quarrel, there are the usual true and false literals, but also yes and no which are equivalent to their respective counterparts. There are several primitve contracts to support using truth values.
Aggregate#
Quarrel provides Sequences, Lists, Maps, Sets, and Patterns for aggregate data types. Sequences use ( ) operators to both create and invoke. Lists use [ ] operators to create and index. Maps and Sets both use < > but with maps, you provide a key-value pair. Patterns use { } for creation, parametric arguments, and for creating subcontracts (literal named patterns within a pattern container accessible with -> or \ operators).
Auxiliary#
These primitive contracts will help you check metadata around containers.
Primitive Method Operators#
All primitives come with method operators that use the main syntactic grouping operator (( ), [ ], { }, or < >) and an infix operator (e.g., [+]) to represent builtin methods that are included within the standard language.
Sequence#
| Method Operator | Action |
|---|---|
(+) | Add a new routine to the container |
(:) | Clone the container of sequences |
(_:) | Cloned list of all parameter patterns |
(?) | Check for a matching parameter pattern |
(-) | Change a routine by looking up it's parameter pattern |
(@) | Count of how many routines are contained |
List#
| Method Operator | Action |
|---|---|
[x] | Get the xth element |
[+] | Push a new list item onto the end of the list |
[@] | Return the size of the list |
[!] | Delete a list item (at index provided) |
[<:] | First element of the list |
[:>] | Last element of the list |
[<:x] | First x element(s) of the list |
[x:>] | Last x element(s) of the list |
[<!] | Take the first element, removing it from the original list |
[!>] | Take the last element, removing it from the original list |
[<!x] | Take the first x element(s), removing them from the original list |
[x!>] | Take the last x element(s), removing them from the original list |
Map#
| Method Operator | Action |
|---|---|
<x> | Get the value at the x key |
<?> | Check if map has a key |
<@> | Return the size of the map (how many keys) |
<!> | Delete a key and its value |
<_:> | Get a list of the map's keys |
<:_> | Get a list of map's values |
Set#
| Method Operator | Action |
|---|---|
<x> | Check if the set contains this value |
<+> | Add a value to a set |
<@> | Return the size of the set |
<!> | Delete a value in a set |
Pattern#
| Method Operator | Action |
|---|---|
{C1,C2,...} | Positional contract/pattern parameters that are used inside patterns that have \1, \2, etc. template parameters. |
(p1,p2,...) | Positional parameters that are provided in the order that the pattern indicates to create custom structured aggregate data. |
{@} | The size of the custom structured data that can be represented by this pattern. |