It seems to be working in a mock-environment

source/parse-query-tree.js

@@ -0,0 +1,98 @@
+//build the tokens into a single object of types representing the initial query
+const parseQueryTree = (tokens, typeGraph, options) => {
+	let current = 1; //primed
+
+	//TODO: check for top-level keywords
+
+	//get a token that matches a type
+	if (!typeGraph[tokens[current - 1]]) {
+		throw `Expected a type in the type graph (found ${tokens[current - 1]})`;
+	}
+
+	//read the block of lines
+	const [block, pos] = readBlock(tokens, current, tokens[current - 1], typeGraph, options);
+
+	//insert the typename into the top-level block
+	block['typeName'] = tokens[current - 1];
+
+	//finally
+	return block;
+};
+
+const readBlock = (tokens, current, superType, typeGraph, options) => {
+	//scan the '{'
+	if (tokens[current++] != '{') {
+		throw `Expected '{'`;
+	}
+
+	//result
+	const result = {};
+
+	//scan each "line" in this block
+	while(tokens[current++]) {
+		//check for end of block
+		if (tokens[current - 1] == '}') {
+			break;
+		}
+
+		//check for block-level keywords
+		let modifier = null;
+		if (['match'].includes(tokens[current - 1])) {
+			modifier = tokens[current - 1];
+			current++;
+		}
+
+		//read field name
+		const fieldName = tokens[current - 1];
+
+		if (options.debug) {
+			console.log(`Trying to process field ${fieldName}`);
+		}
+
+		//if the field is non-scalar, read the sub-block
+		if (!typeGraph[typeGraph[superType][fieldName].typeName].scalar) {
+			//recurse
+			const [block, pos] = readBlock(tokens, current, typeGraph[superType][fieldName].typeName, typeGraph, options);
+
+			//insert the typename into the block
+			block['typeName'] = typeGraph[superType][fieldName].typeName;
+
+			//insert into result
+			result[fieldName] = block;
+
+			//insert the block-level modifier signal
+			if (modifier) {
+				result[fieldName][modifier] = true;
+			}
+
+			current = pos; //pos points past the end of the block
+
+			if (options.debug) {
+				console.log(`${fieldName}: ${JSON.stringify(result[fieldName])}`);
+			}
+
+			continue;
+		}
+
+		//scalar
+		else {
+			//save the typeGraph type into result
+			result[fieldName] = JSON.parse(JSON.stringify( typeGraph[ typeGraph[superType][fieldName].typeName ] ));
+
+			//insert the block-level modifier signal
+			if (modifier) {
+				result[fieldName][modifier] = tokens[current++];
+			}
+
+			if (options.debug) {
+				console.log(`${fieldName}: `, result[fieldName]);
+			}
+
+			continue;
+		}
+	}
+
+	return [result, current];
+};
+
+module.exports = parseQueryTree;