1 files changed, 171 insertions, 0 deletions
diff --git a/blog/data/poll.js b/blog/data/poll.js
new file mode 100644
index 0000000..55b4e22
--- /dev/null
+++ b/blog/data/poll.js
@@ -0,0 +1,171 @@
+//By Chris Xiong, 2018
+//License: Expat
+let p=null;
+let Caption;
+let Choices;
+let Score;
+let Next;
+let values=[];
+let curq;
+function evalexpr(e)
+{
+	let ret=0;
+	let op=function(a,o,b){
+		switch(o){
+			case '+':return a+b;
+			case '-':return a-b;
+			case '*':return a*b;
+			case '/':return a/b;
+		}
+	};
+	for(let p=e.match(/[+\-*\/]/);p;p=e.match(/[+\-*\/]/))
+	{
+		let vp=e.match(/[A-Za-z]\w*/);
+		if(vp)
+		{
+			const v=vp[0];
+			if(values[v]===undefined)throw 'shit';
+			ret=op(ret,p[0],values[v]);
+			e=e.substr(vp.index+vp[0].length);
+		}
+		else
+		{
+			let np=e.match(/\d+(.\d*)?/);
+			if(np)
+			{
+				const n=Number(np[0]);
+				ret=op(ret,p[0],n);
+				e=e.substr(np.index+np[0].length);
+			}else throw 'shit';
+		}
+	}
+	return ret;
+}
+function evalsetexpr(e)
+{
+	const s=e.split('=');
+	if(s.length<2)throw 'shit';
+	values[s[0].trim()]=evalexpr(s[1]);
+}
+function evaltestexpr(e)
+{
+	const m=e.match(/([A-Za-z]\w*)\s*(leq|geq|lt|gt)\s*([A-Za-z0-9.]*)/);
+	if(!m)throw 'shit';
+	const v=m[1],op=m[2],vr=m[3];
+	const vv=values[v];
+	const vvr=isNaN(Number(vr))?values[vr]:Number(vr);
+	if(vv===undefined||vvr===undefined)throw 'shit';
+	switch(op.trim())
+	{
+		case 'leq':return vv<=vvr;
+		case 'geq':return vv>=vvr;
+		case 'lt':return vv<vvr;
+		case 'gt':return vv>vvr;
+	}
+	throw 'shit';
+}
+function evalcondexpr(e)
+{
+	if(!e.trim().length)return true;
+	let ret=false;
+	let op=function(a,o,b){
+		switch(o){
+			case '|':return a||b;
+			case '&':return a&&b;
+		}
+	};
+	for(let p=e.search(/[|&]/);p!=-1;p=e.search(/[|&]/))
+	{
+		let np=e.substr(p+1).search(/[|&]/);
+		let n=e.substr(p+1,np!=-1?np-1:undefined);
+		ret=op(ret,e[p],evaltestexpr(n.trim()));
+		e=np?e.substr(np):"";
+	}
+	return ret;
+}
+function initq()
+{
+	const q=p.question[curq];
+	for(let i=0;i<q.initialization.length;++i)
+	{
+		if(evalcondexpr(q.initialization[i].c))
+		evalsetexpr(q.initialization[i].s);
+	}
+	if(!evalcondexpr(q.precond)){++curq;if(curq<p.question.length)initq();else finalize();}
+}
+function evalq()
+{
+	if(curq>=p.question.length)return;
+	const q=p.question[curq];
+	let seln=0;
+	for(let i=0;i<q.choice.length;++i)
+	{
+		const e=document.getElementById(`choice${i}`);
+		if(e.checked)++seln;
+		if(e.checked)
+		{
+			for(let j=0;j<q.choice[i].setp.length;++j)
+				if(evalcondexpr(q.choice[i].setp[j].c))
+				evalsetexpr(q.choice[i].setp[j].s);
+		}
+		else
+		{
+			for(let j=0;j<q.choice[i].setn.length;++j)
+				if(evalcondexpr(q.choice[i].setn[j].c))
+				evalsetexpr(q.choice[i].setn[j].s);
+		}
+	}
+	if(!seln&&q.type=='single'){alert('Wanna cheat?...');return;}
+	++curq;
+	if(curq==p.question.length)finalize();else{showq();initq();}
+}
+function showq()
+{
+	const q=p.question[curq];
+	Caption.innerHTML=q.caption;
+	while(Choices.firstChild)Choices.removeChild(Choices.firstChild);
+	for(let i=0;i<q.choice.length;++i)
+	{
+		const d=document.createElement('div');
+		const e=document.createElement('input');
+		e.type=q.type=='multi'?'checkbox':'radio';
+		e.innerHTML=q.choice[i].caption;
+		e.qid=i;e.id=`choice${i}`;
+		e.setAttribute('name','choice');
+		e.classList.add('check');
+		const l=document.createElement('label');
+		l.innerHTML=q.choice[i].caption;
+		l.setAttribute('for',e.id);
+		d.appendChild(e);
+		d.appendChild(l);
+		Choices.appendChild(d);
+	}
+	Score.innerHTML=`${values['score']}, Question ${curq+1}/${p.question.length}`;
+}
+function _init()
+{
+	Caption=document.getElementById('qcaption');
+	Choices=document.getElementById('qchoices');
+	Score=document.getElementById('score');
+	Next=document.getElementById('nextbtn');
+	curq=0;values['score']=0;
+	initq();showq();
+}
+async function init()
+{
+	const resp=await fetch(new Request('/blog/data/applefan.json'));
+	r=await resp.text();
+	p=JSON.parse(r);
+	_init();
+}
+function finalize()
+{
+	Next.style.color='#888';
+	Score.innerHTML=`${values['score']}, Question ${p.question.length}/${p.question.length}`;
+	Caption.innerHTML='';
+	Choices.innerHTML='';
+	for(let i=0;i<p.verdict.length;++i)
+	if(evalcondexpr(p.verdict[i].precond))
+		Caption.innerHTML+=p.verdict[i].caption;
+}
+init();