refactor: _evalToken renamed to evalToken

BREAKING CHANGE: `evalToken` now returns a generator (LiquidJS async), which is different from `evalToken` in previous LiquidJS versions.

src/template/filter.ts

@@ -1,4 +1,4 @@
-import { _evalToken } from '../render'
+import { evalToken } from '../render'
 import { Context } from '../context'
 import { identify } from '../util/underscore'
 import { FilterImplOptions } from './filter-impl-options'
@@ -20,8 +20,8 @@ export class Filter {
   public * render (value: any, context: Context): IterableIterator<unknown> {
     const argv: any[] = []
     for (const arg of this.args as FilterArg[]) {
-      if (isKeyValuePair(arg)) argv.push([arg[0], yield _evalToken(arg[1], context)])
-      else argv.push(yield _evalToken(arg, context))
+      if (isKeyValuePair(arg)) argv.push([arg[0], yield evalToken(arg[1], context)])
+      else argv.push(yield evalToken(arg, context))
     }
     return this.impl.apply({ context, liquid: this.liquid }, [value, ...argv])
   }

src/template/hash.ts

@@ -1,4 +1,4 @@
-import { _evalToken } from '../render/expression'
+import { evalToken } from '../render/expression'
 import { Context } from '../context/context'
 import { Tokenizer } from '../parser/tokenizer'
 import { Token } from '../tokens/token'
@@ -24,7 +24,7 @@ export class Hash {
   * render (ctx: Context): Generator<unknown, Record<string, any>, unknown> {
     const hash = {}
     for (const key of Object.keys(this.hash)) {
-      hash[key] = this.hash[key] === undefined ? true : yield _evalToken(this.hash[key], ctx)
+      hash[key] = this.hash[key] === undefined ? true : yield evalToken(this.hash[key], ctx)
     }
     return hash
   }