It's a little buggy, but matching is working

This commit is contained in:
2020-09-06 01:54:31 +10:00
parent d52b63bcf4
commit 5183f89c91
3 changed files with 76 additions and 30 deletions

View File

@@ -17,11 +17,11 @@ const main = (schema, handler) => {
//the receiving function - this will be called multiple times
return async reqBody => {
//parse the query
const tokens = reqBody.split(/(\s+)/).filter(s => s.trim().length > 0); //TODO: proper token parsing
let pos = 0;
try {
//parse the query
const tokens = reqBody.split(/(\s+)/).filter(s => s.trim().length > 0); //TODO: proper token parsing
let pos = 0;
//check for keywords
switch(tokens[pos]) {
case 'create':
@@ -168,11 +168,18 @@ const parseQuery = async (handler, tokens, pos, typeGraph, parent = null) => {
throw 'Expected \'{\' after queried type';
}
//the scalars to pass to the handler
//the scalars to pass to the handler - these are NEIGHBOURS in the hierarchy
const scalarFields = [];
const deferredCalls = []; //functions (promises) that will be called at the end of this function
while(tokens[pos] && tokens[pos] != '}') { //while not at the end of this block
let match = false;
if (tokens[pos] === 'match') {
match = true;
pos++;
}
//prevent using keywords
if (keywords.includes(tokens[pos])) {
throw 'Unexpected keyword ' + tokens[pos];
@@ -181,7 +188,12 @@ const parseQuery = async (handler, tokens, pos, typeGraph, parent = null) => {
//type is a scalar, and can be queried
if (typeGraph[queryType] && typeGraph[queryType][tokens[pos]] && typeGraph[typeGraph[queryType][tokens[pos]].typeName].scalar) {
//push the scalar object to the queryFields
scalarFields.push({ typeName: typeGraph[queryType][tokens[pos]].typeName, name: tokens[pos] });
scalarFields.push({ typeName: typeGraph[queryType][tokens[pos]].typeName, name: tokens[pos], match: match ? tokens[++pos] : null });
//if I am a scalar child of a match amd I do not match
if (parent && parent.match && !match) {
throw 'Broken match chain in scalar type ' + tokens[pos];
}
pos++;
}
@@ -189,24 +201,34 @@ const parseQuery = async (handler, tokens, pos, typeGraph, parent = null) => {
const pos2 = pos; //cache the value to keep it from changing
//recurse
deferredCalls.push(async (result) => [tokens[pos2], await parseQuery(
handler,
tokens,
pos2,
typeGraph,
{ typeName: queryType, scalars: scalarFields, context: result } //parent object
)]);
deferredCalls.push(async (result) => {
//if I am a compound child of a match amd I do not match
if (parent && parent.match && !match) {
throw 'Broken match chain in compound type ' + tokens[pos2];
}
return [tokens[pos2], await parseQuery(
handler,
tokens,
pos2,
typeGraph,
{ typeName: queryType, scalars: scalarFields, context: result, match: match } //parent object (this one)
), match]; //HACK: match piggybacking on the tuple
});
pos = eatBlock(tokens, pos + 2);
} else {
//token is something else?
console.log('something else: ', tokens[pos], pos);
pos++;
throw 'Found something not in the type graph: ' + tokens[pos] + " " + pos;
}
}
//eat the end bracket
pos++;
if (!handler[queryType]) {
throw 'Unrecognized type ' + queryType;
}
let results = handler[queryType](parent, scalarFields);
@@ -214,11 +236,17 @@ const parseQuery = async (handler, tokens, pos, typeGraph, parent = null) => {
results = await Promise.all(results.map(async res => {
const tuples = await Promise.all(deferredCalls.map(async call => await call(res)));
if (!tuples.every(tuple => !tuple[2] || tuple[1].length > 0)) {
console.log('discarding', tuples);
return [];
}
tuples.forEach(tuple => res[tuple[0]] = tuple[1]);
return res;
}));
results = results.filter(r => Array.isArray(r) && r.length == 0 ? false : true);
return results;
};