QuickParse

QuickParse is a "de-templating" library for fast prototyping born during solving tasks from Advent of Code 2021.

QuickStart

Introduction and templates

Let's say we have an input that is clearly derived from some kind of template, but differs with arguments:

target area: x=20..30, y=-10..-5

target area: x=3..12, y=-1..-52

QuickParse wants to make obtaining values from this format as fast as possible - from the viewpoint of you, the programmer (who likes parsing anyways?).

Firstly, we need to define the QuickParse template:

target area: x=$(int){x1}$..$(int){x2}$, y=-$(int){y1}$..$(int){y2}$

every potential object that we want to catch needs to be signified with the dollar sign symbol ($). Naming the object (using curly brackets {, }) and type of the object (using brackets (, )) is optional - QuickParse defaults the type to String, and does not give a name to the objects.

To escape dollar sign parsing, you can replace it with the double dollar sign ($$). Escaping in object names and type names is currently not supported.

Keep in mind that complex capture groups (those with name or type) must start and end with the dollar sign, however simple capture groups are composed of a single dollar sign.

Outputs

QuickParse supports three default output options:

• to class instance
• to map
• to list

Exporting parsed objects to the class instance requires you to follow the naming structure of given class - so here using names for the objects is required. Exporting parsed objects to the list ignores their names.

Code example

public class Coords {
    private int x1;
    private int x2;
    private int y1;
    private int y2;
}

String template = "target area: x=$(int){x1}$..$(int){x2}$, y=-$(int){y1}$..$(int){y2}$";
String input = "target area: x=11..12, y=-13..-14";
Coords coords = QuickParse.parseToObject(template, input, new Coords(), Coords.class);
coords.x1; //<-- now it's 11
coords.x2; //<-- now it's 12
coords.y1; //<-- now it's -13
coords.y2; //<-- now it's -14

Optimization

QuickParse supports pattern compilation for reuse.

Parsers

Out-of-the-box QuickParse supports following type parsers:

• String (default) - returns the input string
• int - tries to parse the int as an integer
• Integer - tries to parse the int as a null value or an integer