hyTags
Types
Overview
hyTags is dynamically typed. Every value on the stack has a type, and commands expect parameters of particular types. Type errors are caught at runtime and throw exceptions.
Command Naming
Commands that operate on a specific type follow the naming pattern
type-function. For example,
string-append appends to a string, and
number-add adds to a number.
Type-based commands typically have a
self parameter that refers to the value being operated on. This parameter is read from the stack by type:
<button>Self parameter</button> <on click> <string-new value="Hello"> <!-- Stack: ["Hello"] --> <string-append string=" World"> <!-- self = "Hello" (from stack) --> <debug-log> <!-- Logs: "Hello World" --> </on>
Primitive Types
- string: Text values. Commands:
string-new,string-append,string-split,string-replace, etc. - number: Numeric values (integers and decimals). Commands:
number-new,number-add,number-multiply,number-round, etc. - bool: Boolean values. Commands:
bool-true,bool-false,bool-and,bool-or,bool-not.
Collection Types
- array: An ordered list of values. Arrays are typed:
[string]holds strings,[number]holds numbers. Commands:array-new,array-append,array-get,array-loop, etc. - object: A key-value dictionary with string keys. Commands:
object-new,object-set,object-get,object-get-keys.
DOM Types
- element: A single DOM element. Commands:
element-new,element-clone,selection-get-element. - fragment: A collection of DOM nodes. Commands:
fragment-new,fragment-replace,selection-append-children. - event: An event object passed to handlers. Commands:
event-get,event-get-target,event-get-key.
Date and Time Types
- date: A calendar date (year, month, day). Commands:
date-new,date-now,date-add,date-to-string. - time: A time of day (hour, minute, second). Commands:
time-new,time-now,time-to-string. - dateTime: A combined date and time. Commands:
date-time-new,date-time-now,date-time-to-string.
Network Types
- url: A parsed URL with components. Commands:
url-new,url-from-string,url-get-path,url-add-query-param. - request: An HTTP request being built. Commands:
request-new,request-set-object,request-send. - response: The result of an HTTP request. Commands:
response-is-success,response-get-object,response-get-fragment. - error: An error from a failed request. Commands:
error-get-code,error-get-message. - formData: Form data for HTTP requests. Commands:
form-get-data,request-set-form-data.
Other Types
- rect: A rectangle with position and size. Commands:
selection-get-frame-rect,rect-get-left,rect-get-width. - closure: A block of commands stored for later execution. Commands:
closure-new,closure-execute.
Type and Return Parameters
Some commands work with multiple types. These use a
type parameter to specify which type to operate on, or a
return parameter to specify the result type.
For example,
var-set stores a value of any type. The
type parameter tells it what type the value is:
<button>Type parameter</button> <on click> <var-set name="count" value="0" type="number"></var-set> <var-set name="label" value="Items" type="string"></var-set> </on>
Commands like
selection-scope use a
return parameter to specify what type the inner commands will produce:
<button>Return parameter</button>
<on click>
<selection-scope next-sibling="div" return="string">
<selection-get-text>
</selection-scope>
<!-- String from scope is now on the stack -->
<debug-log>
</on>
<div>Hello</div>
