perf: remove transient strings to reduce memory

benchmark/memory.js

@@ -28,10 +28,12 @@ function html () {
   for (let i = 0; i < SAMPLE_COUNT; i++) {
     templates.push(engine.parse(str))
   }
-  global.gc()
+  const diff1 = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
+  console.log(`${h(str.length)} lorem-html before GC x ${h(diff1)}/tpl (${SAMPLE_COUNT} instances sampled)`)
 
-  const diff = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
-  console.log(`${h(str.length)} HTML template x ${h(diff)}/instance (${SAMPLE_COUNT} instances sampled)`)
+  global.gc()
+  const diff2 = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
+  console.log(`${h(str.length)} lorem-html after GC x ${h(diff2)}/tpl (${SAMPLE_COUNT} instances sampled)`)
 }
 
 function todolist () {
@@ -44,10 +46,12 @@ function todolist () {
   for (let i = 0; i < SAMPLE_COUNT; i++) {
     templates.push(engine.parse(str))
   }
-  global.gc()
+  const diff1 = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
+  console.log(`${h(str.length)} todolist before GC x ${h(diff1)}/tpl (${SAMPLE_COUNT} instances sampled)`)
 
-  const diff = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
-  console.log(`${h(str.length)} Todo template x ${h(diff)}/instance (${SAMPLE_COUNT} instances sampled)`)
+  global.gc()
+  const diff2 = (getHeapStatistics().used_heap_size - base) / SAMPLE_COUNT
+  console.log(`${h(str.length)} todolist after GC x ${h(diff2)}/tpl (${SAMPLE_COUNT} instances sampled)`)
 }
 
 function h (size) {

rollup.config.ts

@@ -49,11 +49,6 @@ const esm = {
       delimiters: ['', ''],
       './fs/node': './fs/browser'
     }),
-    replace({
-      include: './src/parser/token.ts',
-      delimiters: ['', ''],
-      './flatten/node': './flatten/browser'
-    }),
     typescript({
       tsconfigOverride: {
         include: [ 'src' ],
@@ -83,11 +78,6 @@ const umd = {
       delimiters: ['', ''],
       './fs/node': './fs/browser'
     }),
-    replace({
-      include: './src/parser/token.ts',
-      delimiters: ['', ''],
-      './flatten/node': './flatten/browser'
-    }),
     typescript({
       tsconfigOverride: {
         include: [ 'src' ],
@@ -116,11 +106,6 @@ const min = {
       delimiters: ['', ''],
       './fs/node': './fs/browser'
     }),
-    replace({
-      include: './src/parser/token.ts',
-      delimiters: ['', ''],
-      './flatten/node': './flatten/browser'
-    }),
     typescript({
       tsconfigOverride: {
         include: [ 'src' ],

src/context/context.ts

@@ -80,6 +80,7 @@ export class Context {
   private parseProp (str: string) {
     str = String(str)
     const seq: string[] = []
+    const push = () => name.length && (seq.push(name), (name = ''))
     let name = ''
     let j
     let i = 0
@@ -120,11 +121,6 @@ export class Context {
       throw new TypeError(`invalid path:"${str}"`)
     }
     return seq
-
-    function push () {
-      if (name.length) seq.push(name)
-      name = ''
-    }
   }
 }
 

src/parser/filter-token.ts

@@ -12,6 +12,5 @@ export class FilterToken extends Token {
     file?: string
   ) {
     super(raw, input, line, col, file)
-    this.type = 'filter'
   }
 }

src/parser/html-token.ts

@@ -3,10 +3,9 @@ import { Token } from './token'
 export class HTMLToken extends Token {
   public constructor (str: string, input: string, line: number, col: number, file?: string) {
     super(str, input, line, col, file)
-    this.type = 'html'
     this.content = str
   }
   public static is (token: Token): token is HTMLToken {
-    return token.type === 'html'
+    return token instanceof HTMLToken
   }
 }

src/parser/output-token.ts

@@ -13,9 +13,8 @@ export class OutputToken extends DelimitedToken {
     file?: string
   ) {
     super(raw, value, input, line, pos, options.trimOutputLeft, options.trimOutputRight, file)
-    this.type = 'output'
   }
   public static is (token: Token): token is OutputToken {
-    return token.type === 'output'
+    return token instanceof OutputToken
   }
 }

src/parser/substr.ts

@@ -0,0 +1,19 @@
+export class Substr {
+  constructor (
+    public str: string,
+    public begin: number,
+    public end: number = begin
+  ) {}
+  size () {
+    return this.end - this.begin
+  }
+  toString () {
+    return this.str.slice(this.begin, this.end)
+  }
+  first () {
+    return this.str[this.begin]
+  }
+  last () {
+    return this.str[this.end - 1]
+  }
+}

src/parser/tag-token.ts

@@ -17,7 +17,6 @@ export class TagToken extends DelimitedToken {
     file?: string
   ) {
     super(raw, value, input, line, pos, options.trimTagLeft, options.trimTagRight, file)
-    this.type = 'tag'
     const match = this.content.match(lexical.tagLine)
     if (!match) {
       throw new TokenizationError(`illegal tag syntax`, this)
@@ -26,6 +25,6 @@ export class TagToken extends DelimitedToken {
     this.args = match[2]
   }
   public static is (token: Token): token is TagToken {
-    return token.type === 'tag'
+    return token instanceof TagToken
   }
 }

src/parser/token.ts

@@ -1,18 +1,14 @@
-import { flatten } from './flatten/node'
-
 export class Token {
   public trimLeft = false
   public trimRight = false
-  public type = 'notset'
-  public raw: string
   public content: string
-  public constructor (raw: string,
+  public constructor (
+    public raw: string,
     public input: string,
     public line: number,
     public col: number,
     public file?: string
   ) {
-    this.raw = flatten(raw)
     this.content = raw
   }
 }