njseries_03_08.js

class Templater {
    ...
    _parse(ast, stops){
        while(this._parser.pos < this._parser.tokens.length){
            let token = this._parser.tokens[this._parser.pos]
            let expr = token.replace(/[%{}]/g, '').trim().split(/\s(.+)/)
            
            if(stops && Array.isArray(expr) && stops.includes(expr[0])) {
                this._parser.pos += 1
                return expr[0] //stop parsing nested block
            }

            //output
            if(token.startsWith('{{')){
                let outNode = new OutNode(this._parser, [token])
                outNode.parse(ast)
                continue
            }

            let keyword = expr[0]
            
            //extend
            if(keyword === 'extends'){
                let templateNode = new TemplateNode(this._parser, expr)
                templateNode.parse(ast)
                continue
            }

            //block
            if(keyword === 'block'){
                let blockNode = new BlockNode(this._parser, expr)
                blockNode.parse(ast)
                continue
            }

            
            //if
            if(keyword === 'if'){
                let ifNode = new IfNode(this._parser, expr)
                ifNode.parse(ast)
                continue
            }

            //for
            if(keyword === 'for'){
                let forNode = new ForNode(this._parser, expr)
                forNode.parse(ast)
                continue
            }

            //text
            let textNode = new TextNode(this._parser, [token])
            textNode.parse(ast)
        }
    }
    ...
}