ksql   ![Latest Version]

Is a JSON data expression lexer, parser, cli and library.

How to install CLI

shell ~ cargo install ksql

Usage

```rust use ksql::parser::{Parser, Value}; use std::error::Error;

fn main() -> Result<(), Box>{ let src = r#"{"name":"MyCompany", "properties":{"employees": 50}"#.asbytes(); let expression = ".properties.employees > 20"; let ex = Parser::parse(expression.asbytes())?; let result = ex.calculate(src)?; assert_eq!(Value::Bool(true), result); Ok(()) } ```

CLI Usage

shell ~ ksql '(.field1 + 1) /2' '{"field1": 1}' or echo '{"field1": 1}' | ksql '(.field1 + 1) /2'

Expressions

Expressions support most mathematical and string expressions see below for details:

Syntax & Rules

| Token | Example | Syntax Rules | |----------------|--------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Equals | == | supports both == and =. | | Add | + | N/A | | Subtract | - | N/A | | Multiply | * | N/A | | Divide | / | N/A | | Gt | > | N/A | | Gte | >= | N/A | | Lt | < | N/A | | Lte | <= | N/A | | OpenParen | ( | N/A | | CloseParen | ) | N/A | | OpenBracket | [ | N/A | | CloseBracket | ] | N/A | | Comma | , | N/A | | QuotedString | "sample text" | Must start and end with an unescaped " character | | Number | 123.45 | Must start and end with a space or '+' or '-' when hard coded value in expression and supports 0-9 +- e characters for numbers and exponent notation. | | BooleanTrue | true | Accepts true as a boolean only. | | BooleanFalse | false | Accepts false as a boolean only. | | SelectorPath | .selector_path | Starts with a . and ends with whitespace blank space. This crate currently uses gjson and so the full gjson syntax for identifiers is supported. | | And | && | N/A | | Not | ! | Must be before Boolean identifier or expression or be followed by an operation | | Or | || | N/A | | Contains | CONTAINS | Ends with whitespace blank space. | | ContainsAny | CONTAINS_ANY | Ends with whitespace blank space. | | ContainsAll | CONTAINS_ALL | Ends with whitespace blank space. | | In | IN | Ends with whitespace blank space. | | Between | BETWEEN | Starts & ends with whitespace blank space. example 1 BETWEEN 0 10 | | StartsWith | STARTSWITH | Ends with whitespace blank space. | | EndsWith | ENDSWITH | Ends with whitespace blank space. | | NULL | NULL | N/A | | Coerce | COERCE | Coerces one data type into another using in combination with 'Identifier'. Syntax is COERCE <expression> _identifer_. | | Identifier | _identifier_ | Starts and end with an _ used with 'COERCE' to cast data types. Currently the only supported Identifier is _datetime_. |