Rule | CS Parser

Constructor

new Rule(Df)

Creates a rule instance with the options in the specified object.

Source:

Rule.js, line 10

Parameters:

Name Type Default Description

Df

object

null

The rule definition object that contains the options as its properties. Definition objects can be nested. A nested definition is interpreted as a sub-rule. The property name for a nested definition must start with $ (dollar sign)

Available Options:

Name Type Default Description

name

string

The name of this rule. Only for debug purpose

from

string | RegExp

The pattern that indicates the begining point of this rule. If the current chunk matched with this pattern, this rule will be activated, and the new context will start parsing from the next chunk

start

Alias of from

to

string | RegExp

The pattern that indicates the end point of this rule. If the current chunk matched with this pattern, this rule will be deactivated, and the current context will be finalized

end

Alias of to

onStart

function

The callback which is called when this rule gets activated.
If this returns false, the Parser will read the current chunk again

Parameters:

Name	Type	Description
`cx`	`Context`	The current context
`chunk`	`string`	The current chunk which has matched with `from`
`matches`	`number` \| `Array.<string>`	If the `from` pattern is a string, the index of the matched string in the chunk. If the `from` pattern is a RegExp, the regex matching results array

init

Alias of onStart

onActive

function

The callback which is called for every single chunk.
If this returns false, the Parser will read the current chunk again

Parameters:

Name	Type	Description
`cx`	`Context`	The current context
`chunk`	`string`	The current chunk

parse

Alias of onActive

onEnd

function

The callback which is called when this rule gets deactivated. If this returns false, the Parser will read the current chunk again

Parameters:

Name	Type	Description
`cx`	`Context`	The current context
`chunk`	`string`	The current chunk which has matched with `to`
`matches`	`number` \| `Array.<string>`	If the `to` pattern is a string, the index of the matched string in the chunk. If the `to` pattern is a RegExp, the regex matching results array

fin

Alias of onEnd

onOutline

function

Debug purpose only. You can customize the output of Context#outline with this callback

Must Return:

The output string

Parameters:

Name	Type	Description
`cx`	`Context`	The context to express

express

Alias of onOutline

on

object

The container for the another aliases of onStart, onActive, onEnd, onOutline

Properties:

Name	Type	Description
`start`	`function`	Alias of `onStart`
`active`	`function`	Alias of `onActive`
`end`	`function`	Alias of `onEnd`
`outline`	`function`	Alias of `onOutline`

isRecursive

boolean

false

Whether this rule is recursive

recursive

Alias of isRecursive

recurse

Alias of isRecursive

endsWithParent

boolean

false

If true, the parent rule can end even when this rule is active

splitter

string | RegExp

'\n'

The chunk splitter. When the Parser reached at the chunk splitter, the substring from the previous chunk splitter is passed to the rule as a chunk. The default splitter is a line-break

encoding

string

Rule.INHERIT

The encoding to use for converting the buffer to a chunk string. Falls back to 'utf8'

$any

object

A sub-rule definition. The property name can be any string but must start with $ (dollar sign)

Extends

Composite

Members

(static, constant) INHERIT :Symbol

The enum for rule properties, which means the actual property value inherits from the parent rule

Source:

Rule.js, line 138

Type:

Symbol

(readonly) ancestors :Array.<Composite>

The ancestor composites ordered by closest to furthest

Inherited From:

Composite#ancestors

Source:

Composite.js, line 43

Type:

Array.<Composite>

encoding :string

The encoding to decode buffers. Falls back to 'utf8'

Default Value:

Rule.INHERIT

Source:

Rule.js, line 310

Type:

string

end :RegExp

The end pattern

Deprecated:

Use Rule#to instead

Default Value:

null

Source:

Rule.js, line 203

Type:

RegExp

endsWithParent :boolean

Whether the current context can also be ended by the parent context rule

Default Value:

false

Source:

Rule.js, line 284

Type:

boolean

from :RegExp

The start pattern

Default Value:

null

Source:

Rule.js, line 160

Type:

RegExp

(readonly) hasChild :boolean

Whether this has one or more child composites

Inherited From:

Composite#hasChild

Source:

Composite.js, line 25

Type:

boolean

(readonly) hasParent :boolean

Whether this has parent composite

Inherited From:

Composite#hasParent

Source:

Composite.js, line 16

Type:

boolean

isRecursive :boolean

Whether this rule is recursive

Default Value:

false

Source:

Rule.js, line 271

Type:

boolean

(readonly) length :number

The number of child composites

Inherited From:

Composite#length

Source:

Composite.js, line 69

Type:

number

name :string

The name of this rule

Default Value:

Source:

Rule.js, line 147

Type:

string

onActive :function

The event handler which is called every time the parser reached at Rule#splitter

Default Value:

null

Source:

Rule.js, line 232

Type:

function

onEnd :function

The event handler which is called when this rule is deactivated

Default Value:

null

Source:

Rule.js, line 244

Type:

function

onOutline :function

Debug purpose only. The callback which runs when Context#outline is called

Default Value:

null

Source:

Rule.js, line 258

Type:

function

onStart :function

The event handler which is called when this rule is activated

Default Value:

null

Source:

Rule.js, line 218

Type:

function

(readonly) parent :Composite

The parent composite

Inherited From:

Composite#parent

Source:

Composite.js, line 34

Type:

Composite

(readonly) root :Composite

The root of composition

Inherited From:

Composite#root

Source:

Composite.js, line 58

Type:

Composite

splitter :string|RegExp

The chunk splitter

Default Value:

'\n'

Source:

Rule.js, line 297

Type:

string | RegExp

start :RegExp

The start pattern

Deprecated:

Use Rule#from instead

Default Value:

null

Source:

Rule.js, line 174

Type:

RegExp

to :RegExp

The end pattern

Default Value:

null

Source:

Rule.js, line 189

Type:

RegExp

Methods

addChild(Cp) → {Composite}

Adds a child composite

Inherited From:

Composite#addChild

Source:

Composite.js, line 89

Parameters:

Name	Type	Description
`Cp`	`Composite`	The composite to add as a child

Returns:

Type:: Composite

This

addChildren(Cps) → {Composite}

Adds multiple child composites

Inherited From:

Composite#addChildren

Source:

Composite.js, line 106

Parameters:

Name	Type	Description
`Cps`	`Array.<Composite>`	The array of the composites to add

Returns:

Type:: Composite

This

endsWith(Chunk) → {mixed}

Performs matching the specified chunk with the end pattern

Source:

Rule.js, line 358

Parameters:

Name	Type	Description
`Chunk`	`string`	The chunk to match

Returns:

Type:: mixed

The matching result

express(Cx) → {string}

Expresses a context. Debug purpose only.

Source:

Rule.js, line 481

Parameters:

Name	Type	Description
`Cx`	`Context`	The context to express

Returns:

Type:: string

fin(Cx, Chunk, MatchResult) → {boolean}

Finalizes a context

Source:

Rule.js, line 450

Parameters:

Name	Type	Default	Description
`Cx`	`Context`		The context to finalize
`Chunk`	`string`	''	The chunk that matched with the `end` condition
`MatchResult`	`Array.<string>`	null	The maching result of the `end` condition

Returns:

Type:: boolean

Result of fin callback. If fin is not specified, true will be returned

init(Cx, Chunk, MatchResult) → {boolean}

Initializes a context

Source:

Rule.js, line 432

Parameters:

Name	Type	Default	Description
`Cx`	`Context`		The context to initialize
`Chunk`	`string`	''	The chunk that matched with the `start` condition
`MatchResult`	`Array.<string>`	null	The matching result of the `start` condition

Returns:

Type:: boolean

The result of init callback. If init is not specified, true will be returned

on(Ev, Fn)

Sets an event handler

Source:

Rule.js, line 410

Parameters:

Name Type Description

Ev

string

The event identifier

Available Events:

'start': Occurs when the current chunk matched with Rule#from
'active': While this rule is active, occurs every time the parser reached at Rule#splitter
'end': Occurs when the current chunk matched with Rule#to
'outline': Occurs when Context#outline is called. Debug purpose only

Fn

function

The event handler. Returning false makes the parser read the current chunk again

Parameters:

Name	Type	Description
`cx`	`Context`	The current context
`chunk`	`string`	The current chunk. Only for `start`, `active` and `end`
`matches`	`number` \| `Array.<string>`	The matching result of Rule#from/Rule#to. Only for `start` and `end` events

parse(Cx, Chunk) → {boolean}

Parses a chunk

Source:

Rule.js, line 467

Parameters:

Name	Type	Default	Description
`Cx`	`Context`		The current context
`Chunk`	`string`	''	The chunk to parse

Returns:

Type:: boolean

The result of parse callback. If parse is not specified, true will be returned

startsWith(Chunk) → {mixed}

Performs matching the specified chunk with the start pattern

Source:

Rule.js, line 349

Parameters:

Name	Type	Description
`Chunk`	`string`	The chunk to match

Returns:

Type:: mixed

The matching result

traverse(Fn, Depth, Arg) → {boolean}

Performs tree traversal

Inherited From:

Composite#traverse

Source:

Composite.js, line 125

Parameters:

Name	Type	Default	Description
`Fn`	`function`		The callback that receives every descendant composite as the 1st parameter. If `false` is returned, the traversal will be aborted. The returned value other than `false` will be passed to the next traversal call of `Fn` as the 2nd parameter
`Depth`	`number`	-1	The limit of traversal depth. Negative number means no-limit
`Arg`	`mixed`	null	Additinal argument to pass to `Fn` as the 2nd parameter.

Returns:

Type:: boolean

true if the traversal is successfully completed. false if the traversal is aborted

verifyChild(Cp) → {boolean|string}

Determines whether the specified composite can be added as a child

Inherited From:

Composite#verifyChild

Source:

Composite.js, line 80

Parameters:

Name	Type	Description
`Cp`	`Composite`	The composite which is about to be added

Returns:

Type:: boolean | string

true if Cp is valid. Any type other than true means invalid. If a string is returned, it is shown as an error message in the debug console