Types

The jsonpatcher language is dynamically typed, meaning that everything only has a type at runtime. This makes it easier to write simple scripts, which is the primary purpose of jsonpatcher.

The language has seven types: strings, numbers, booleans, arrays, objects, functions, and null. The type system is mostly derived from json, but the addition of functions as values allows for easier creation of libraries.

Strings

Strings are created by surrounding text with double quotes: "Hello, world!". String literals in jsonpatcher support basic escaping: \n, \r, \t, \b, \", \', \\, \0 (null), \x (unicode escape), \u (unicode escape). Strings can be concatenated with + and repeated with *:

"Hello, " + "world!" # -> "Hello, world!" 
"test" * 3 # -> "testtesttest"

There's a standard library of functions available for strings. See Standard Library/Strings for more information.

Numbers

Numbers are created like in most programming languages. There is only one number type for simplicity: 64-bit floating point numbers. Scientific notation is not yet supported.

Numbers support the following operations:

• num1 + num2 Addition
• num1 - num2 Subtraction
• num1 * num2 Multiplication
• num1 / num2 Division
• num1 % num2 Modulo
• num1 ** num2 Exponentiation
• num1 ^ num2 Bitwise XOR on an integer representation
• num1 & num2 Bitwise AND on an integer representation
• num1 | num2 Bitwise OR on an integer representation
• ~num Bitwise NOT on an integer representation
• -num Negation

They can also be compared with the usual comparison operators: ==, !=, <, >, <= and >=

Numbers currently don't have any standard library functions, but the math library contains trigonometric functions and more. See Standard Library/Math for more information.

Booleans and Null

Booleans are either true or false. They are used for comparisons and control flow.

They can be interacted with using the usual operators:

• !bool Logical NOT
• bool1 && bool2 Logical AND
• bool1 || bool2 Logical OR
• bool1 ^ bool2 Logical XOR
• bool1 == bool2 Equality

Null is a special type that only has one value: null. It is used to represent the absence of a value.

Arrays

Arrays store a list of values. They are created by surrounding a comma-separated list of values with square brackets: [1, 2, 3]. The values in an array can be of any type. Arrays can be nested to create multidimensional arrays.

Values from an array can be accessed by index: array[0], array[index]. Arrays can be concatenated using + and repeated with * like strings.

There's a standard library of functions available for arrays. See Standard Library/Arrays for more information.

Objects

Objects store a list of key-value pairs. They are created by surrounding a comma-separated list of key-value pairs with curly brackets: {key1: value1, key2: value2}.

The keys in an object must be strings, but the values can be of any type. Objects can be combined with +. This merges the two objects, overwriting any keys that are present in both with values from the second.

Values from an object can be accessed by key: object["key"], object[key]. Or by using the dot operator: object.key.

There is no standard library for objects (yet).

Functions

Functions are values that can be passed around and called. For more information on functions, see Functions. They have a few standard library functions, viewable at Standard Library/Functions.