feat: static variable analysis (#770)

* feat: static variable analysis

* Accept any iterable from `children`, `arguments`, etc.

* Test analysis of standard tags

* Use `TagToken.tokenizer` instead of creating a new one

* Test analysis of netsted tags

* Group variables by their root value

* Test analysis of nested globals and locals

* Analyze included and rendered templates WIP

* Use existing tokenizer when constructing `Hash`

* Improve test coverage

* Analyze variables from `layout` and `block` tags

* Test analysis of Jekyll style includes

* Handle variables that start with a nested variable

* Async analysis

* Test non-standard tag end to end

* Implement convenience analysis methods on the `Liquid` class

* More analysis convenience methods

* Accept string or template array

* Draft static analysis docs

* Deduplicate variables names

* Fix isolated scope global variable map

* Coerce variables to strings instead of extending String

* Private map instead of extending Map

* Fix e2e test

* Tentatively implement analysis of aliased variables

* Fix nested variable segments array

* Update docs sidebar

src/tokens/liquid-tag-token.ts

@@ -7,7 +7,6 @@ import { Tokenizer, TokenKind } from '../parser'
  */
 export class LiquidTagToken extends DelimitedToken {
   public name: string
-  public args: string
   public tokenizer: Tokenizer
   public constructor (
     input: string,
@@ -17,12 +16,13 @@ export class LiquidTagToken extends DelimitedToken {
     file?: string
   ) {
     super(TokenKind.Tag, [begin, end], input, begin, end, false, false, file)
-
     this.tokenizer = new Tokenizer(input, options.operators, file, this.contentRange)
     this.name = this.tokenizer.readTagName()
     this.tokenizer.assert(this.name, 'illegal liquid tag syntax')
-
     this.tokenizer.skipBlank()
-    this.args = this.tokenizer.remaining()
+  }
+
+  get args (): string {
+    return this.tokenizer.input.slice(this.tokenizer.p, this.contentRange[1])
   }
 }

src/tokens/tag-token.ts

@@ -21,6 +21,7 @@ export class TagToken extends DelimitedToken {
     this.tokenizer.assert(this.name, `illegal tag syntax, tag name expected`)
     this.tokenizer.skipBlank()
   }
+
   get args (): string {
     return this.tokenizer.input.slice(this.tokenizer.p, this.contentRange[1])
   }