typescriptで書くpukiwikiパーサ

parser.ts

class Inline {
    private match = {
        strong: /^''([\s\S]+?)''(?!')/,
        em: /^'''((?:[^_]|__)+?)'''(?!')/,
        br: /^~(?:\n|$)|^(&br;)/,
        text: /^[\s\S]+?(?=[\\<!\[_*`]| {2,}\n|$)/
    }
    
    private out: string;
    private renderer: Renderer;
    
    constructor(){
        this.renderer = new Renderer();
        this.out = "";
    }
    
    public strong(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.strong.exec(src)){
            src = src.substring(cap[0].length);
            this.out += this.renderer.strong(src);
        }
        
        return src;
    }
    
    public em(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.em.exec(src)){
            src = src.substring(cap[0].length);
            this.out += this.renderer.em(src);
        }
        
        return src;
    }
    
    public text(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.text.exec(src)){
            this.out += src;
            src = src.substring(cap[0].length);
        }
        
        return src;
    }
    
    public output(src: string): string {
        while(src){
            src = this.strong(src);
            src = this.em(src);
            src = this.text(src);
        }
        
        return this.out;
    }
}

class Block {
    private match = {
        newline: /^\n+/,
        heading: /^(\*{1,4})(.*?)(?:\n+|$)/,
        text: /^[^\n]+/
    }
    
    private tokens: {type:string, depth: number, text: string}[];
    
    constructor(){
        this.tokens = [];
    }
    
    public newline(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.newline.exec(src)){
            src = src.substring(cap[0].length);
            this.tokens.push({
                type: 'newline',
                text: cap[1],
                depth: 0
            });
        }
        
        return src;
    }
    
    public heading(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.heading.exec(src)){
            src = src.substring(cap[0].length);
            console.log(this.tokens);
            this.tokens.push({
                type: 'heading',
                text: cap[2],
                depth: cap[1].length
            });
        }
        
        return src;
    }
    
    public text(src: string): string {
        var cap: Array<string>;
        if (cap = this.match.text.exec(src)){
            src = src.substring(cap[0].length);
            this.tokens.push({
                type: 'text',
                text: cap[0],
                depth: 0
            });
        }
        
        return src;
    }
    
    public output(src: string): {type:string, depth: number, text: string}[] {
        while(src){
            src = this.newline(src);
            src = this.heading(src);
            src = this.text(src);
        }
        
        return this.tokens;
    }
}

class Renderer {
    public heading(text: string, depth: number): string{
        return '<h' + depth + '>' + text + '<h' + depth + '>';
    }
    
    public strong(text: string): string {
        return '<b>' + text + '</b>';
    }
    
    public em(text: string): string {
        return '<em>' + text + '</em>';
    }
    
    public output(token: {type:string, depth: number, text: string}): string{
        var src = "";
        if (token.type==="heading"){
            src = this.heading(token.text, token.depth);
        }
        
        return src;
    }
}

class Parser{
    private block:Block;
    private inline:Inline;
    private render:Renderer;
    
    constructor(){
        this.block  = new Block();
        this.inline = new Inline();
        this.render = new Renderer();
    }
    
    public exec(input: string): string{
        var tokens = this.block.output(input);
        var output = "";
        for(var i=0; i<tokens.length; i++){
            tokens[i].text = this.inline.output(tokens[i].text);
            output += this.render.output(tokens[i]);
        }
        
        return output;
    }
}