Advance parser

1 files changed, 88 insertions, 0 deletions

diff --git a/genops.js b/genops.js
new file mode 100755
index 0000000..33b688d
--- /dev/null
+++ b/genops.js
@@ -0,0 +1,88 @@
+#!/usr/bin/env node
+const fs=require("fs");
+
+
+function print(/*arguments*/){
+	//console.log.apply(console,arguments);
+	process.stdout.write.apply(process.stdout,arguments);
+}
+
+function pad(s,w,c){
+	s=s+"";
+	if(s.length>=Math.abs(w))return s;
+	if(w<0)return s+Array(-w-s.length+1).join(c?c:" ");
+	else return Array(w-s.length+1).join(c?c:" ")+s;
+}
+
+
+function readopmap(fname){
+	let table=String(fs.readFileSync(fname)).split("\n");
+	let i;
+	for(i=0;i<table.length;i++){
+		if(/Oper.*Prec.*Assoc/.test(table[i]))break;
+	}
+	let header=table[i];
+	table=table.slice(i+1);
+	for(i=0;i<table.length;i++){
+		if(table[i].length==0)break;
+	}
+	table=table.slice(0,i);
+
+	let opsidx=header.indexOf("Oper"),
+	    precidx=header.indexOf("Prec"),
+	    associdx=header.indexOf("Assoc");
+
+	let opmap={};
+
+	for(let row of table){
+		let ops=row.slice(opsidx,precidx).trim().split(" "),
+		    prec=parseInt(row.slice(precidx,associdx).trim(),10),
+		    assoc=row.slice(associdx).replace(/ *([^ ]+).*/,"$1");
+		for(let op of ops){
+			opmap[op]={prec,assoc};
+		}
+	}
+	return opmap;
+}
+
+function outputfunc(opmap,name,gen,padw){
+	print("int "+name+"(const char *op){\n");
+	print("\tswitch(op[0]){\n");
+
+	let firstchars={};
+	for(let k in opmap){
+		if(firstchars[k[0]])firstchars[k[0]].push(k);
+		else firstchars[k[0]]=[k];
+	}
+	let arr=[];
+	for(k in firstchars){
+		arr.push([k,firstchars[k].sort()]);
+	}
+	arr=arr.sort();
+	for(let tup of arr){
+		let k=tup[0],ops=tup[1];
+		print("\t\tcase '"+k+"': return ");
+		for(let op of ops){
+			let cond="";
+			for(j=1;j<op.length;j++)cond+="op["+j+"]=='"+op[j]+"'&&";
+			cond+="op["+j+"]=='\\0'";
+			print(cond+" ? "+pad(gen(opmap[op]),padw)+" : ");
+		}
+		print("-1;\n");
+	}
+
+	print("\t\tdefault: return -1;\n");
+	print("\t}\n");
+	print("}\n");
+}
+
+
+const opmap=readopmap("LANGUAGE.txt");
+outputfunc(opmap,"precedence",o=>o.prec,2);
+print("\n");
+const assocenum={
+	"Prefix": "AS_PREFIX", "Suffix": "AS_SUFFIX",
+	"Left": "AS_LEFT", "Right": "AS_RIGHT",
+	"Nonassociative": "AS_NONASSOC"
+};
+outputfunc(opmap,"associativity",o=>assocenum[o.assoc],-11);