This is a crate contains a parser, execution engine and specification for a super simple language to write readable and memorizable text processing expressions.
This document should be used as specification for language to clarify the development of this package.
This Language holds only two data types; strings and integers. Both are used as literals in arguments of attribute statements.
A str must use double quotes. So "foo" and "!=$)(j0j0802" are both valid strings. If a double quote occurs inside the string, it can be
escaped using \. So strings with escaped double quotes look like this: "\"Quoted Text\"". This is actually all there is to strings. They cant contain
any other escaped chars (such as new lines etc.)
An ìnt is either a single 0 or 1-9 followed by 0-9 as often as wanted. There are no signed integers.
Queries indicate the format of a string which gets tested against it. Currently there are 9 Attributes which are specified:
| Attribute | Resolve to true if the tested string |
|------------------|------------------------------------------------|
| starts <str> | starts with the given string |
| ends <str> | ends with the given string |
| contains <str> | contains a substring equal to the given string |
| equals <str> | exactly equals the given string |
| length <int> | has the given length |
| numeric | contains only numeric chars |
| alpha | contains only alphabetic chars |
| alphanumeric | contains only alphanumeric chars |
| special | contains only special chars |
Currently there are only two binary logical operations: and and or
| Operator | Precedence | Associativity |
|----------|------------|---------------|
| and | 2 | Right |
| or | 1 | Right |
1 or 2 parses as (1 or 2)
1 and 2 parses as (1 and 2)
1 and 2 or 3 parses as ((1 and 2) or 3)
1 or 2 and 3 parses as (1 or (2 and 3))
1 and 2 and 3 parses as (1 and (2 and 3))
1 or 2 or 3 parses as (1 or (2 or 3))
1 or 2 or 3 and 4 or 5 parses as (1 or (2 or ((3 and 4) or 5)))))
Currently not implemented. May come in future versions to enable more complex text processing;