coffeetable.js

"use strict"

var usage = "sjs -l ./coffeetable.js ./examplescript.js"

var indentToBraces = (chr, reader, prevTokens) => {
	var punc = reader.readPunctuator();
	
	// record the whitespace at the start of the current line
	var indentFinder = /\s*/g;
	var i = indentFinder.lastIndex = reader.lineStart;
	
	reader.skipComment();
	
	if (reader.lineStart === i) { // colon wasn't at end of line, abort
		return null;
	}
	
	var outerIndent = indentFinder.exec(reader.source)[0];
	
	indentFinder.lastIndex = reader.lineStart;
	var innerIndent = indentFinder.exec(reader.source)[0];
	
	if (outerIndent.startsWith(innerIndent)) { // no indentation, abort
		return null;
	}
	
	if (!innerIndent.startsWith(outerIndent)) {
		reader.throwSyntaxError("confusing-indent", "Mixed indentation after colon");
	}
	
	var prevStart = reader.lineStart, tokens = [], lastIndent, token, pushPuncBeforeFirstToken = false;
	
	var out = []
	
	do {
		while(prevStart === reader.lineStart) {
			token = reader.readToken();
			if (token.type === reader.Token.Punctuator && ~"}])".indexOf(token.value)) {
				return out.push(reader.makeDelimiter("{}", tokens), token)
			}
			tokens[tokens.length] = token;
			reader.skipComment();
			
			if (reader.index >= reader.length) {
				out.push(reader.makeDelimiter("{}", tokens));
				return out
			}
		}
		
		indentFinder.lastIndex = prevStart = reader.lineStart;
		lastIndent = indentFinder.exec(reader.source)[0];
	} while (lastIndent.startsWith(innerIndent))
	
	if (!outerIndent.startsWith(lastIndent)) {
		reader.throwSyntaxError("confusing-indent", "Mixed indentation in ident block", tokens[tokens.length-1]);
	}
	var lastToken = tokens[tokens.length-1]
	
	if (lastToken.type === reader.Token.Punctuator && ~",".indexOf(lastToken.value)) {
		out.concat([reader.makeDelimiter("{}", tokens), lastToken])
	}
	else {
		out.push(reader.makeDelimiter("{}", tokens))
	}
	return out;
}

module.exports = {
	":": indentToBraces,
	".": (chr, reader) => { // 2...5 should be interpreted as 2 ... 5, not as 2. . .5
		
		var ellipsisLength = 0;
		if (reader.source[reader.index-1] == ".") { // if the first dot was gobbled by an integer (2. in 2...5)
			ellipsisLength++
		}
		while (reader.source[reader.index] == ".") {
			reader.readPunctuator()
			ellipsisLength++
		}
		if (ellipsisLength > 1) {
			return reader.makePunctuator(".".repeat(ellipsisLength))
		}
	}
}