feat: inline comment tag (#514)

* style: remove unnecessary intermediate constant

* feat: add inline comment tag

* refactor: use readIdentifier when reading tag names

* docs: add inline comment tag

src/builtin/tags/index.ts

@@ -18,10 +18,11 @@ import Break from './break'
 import Continue from './continue'
 import echo from './echo'
 import liquid from './liquid'
+import inlineComment from './inline-comment'
 import { TagImplOptions } from '../../template/tag/tag-impl-options'
 
 const tags: { [key: string]: TagImplOptions } = {
-  assign, 'for': For, capture, 'case': Case, comment, include, render, decrement, increment, cycle, 'if': If, layout, block, raw, tablerow, unless, 'break': Break, 'continue': Continue, echo, liquid
+  assign, 'for': For, capture, 'case': Case, comment, include, render, decrement, increment, cycle, 'if': If, layout, block, raw, tablerow, unless, 'break': Break, 'continue': Continue, echo, liquid, '#': inlineComment
 }
 
 export default tags

src/builtin/tags/inline-comment.ts

@@ -0,0 +1,11 @@
+import { TagToken } from '../../tokens/tag-token'
+import { TopLevelToken } from '../../tokens/toplevel-token'
+import { TagImplOptions } from '../../template/tag/tag-impl-options'
+
+export default {
+  parse: function (tagToken: TagToken, remainTokens: TopLevelToken[]) {
+    if (tagToken.args.search(/\n\s*[^#\s]/g) !== -1) {
+      throw new Error('every line of an inline comment must start with a \'#\' character')
+    }
+  }
+} as TagImplOptions

src/parser/tokenizer.ts

@@ -207,8 +207,7 @@ export class Tokenizer {
     const begin = this.p
     let end = this.N
     if (this.readToDelimiter('\n') !== -1) end = this.p
-    const token = new LiquidTagToken(input, begin, end, options, file)
-    return token
+    return new LiquidTagToken(input, begin, end, options, file)
   }
 
   mkError (msg: string, begin: number) {
@@ -234,6 +233,13 @@ export class Tokenizer {
     return new IdentifierToken(this.input, begin, this.p, this.file)
   }
 
+  readTagName (): string {
+    this.skipBlank()
+    // Handle inline comment tags
+    if (this.input[this.p] === '#') return this.input.slice(this.p, ++this.p)
+    return this.readIdentifier().getText()
+  }
+
   readHashes (jekyllStyle?: boolean) {
     const hashes = []
     while (true) {

src/tokens/liquid-tag-token.ts

@@ -23,7 +23,7 @@ export class LiquidTagToken extends DelimitedToken {
       this.args = ''
     } else {
       const tokenizer = new Tokenizer(this.content, options.operatorsTrie)
-      this.name = tokenizer.readIdentifier().getText()
+      this.name = tokenizer.readTagName()
       if (!this.name) throw new TokenizationError(`illegal liquid tag syntax`, this)
 
       tokenizer.skipBlank()

src/tokens/tag-token.ts

@@ -19,7 +19,7 @@ export class TagToken extends DelimitedToken {
     super(TokenKind.Tag, value, input, begin, end, trimTagLeft, trimTagRight, file)
 
     const tokenizer = new Tokenizer(this.content, options.operatorsTrie)
-    this.name = tokenizer.readIdentifier().getText()
+    this.name = tokenizer.readTagName()
     if (!this.name) throw new TokenizationError(`illegal tag syntax`, this)
 
     tokenizer.skipBlank()