Remove helper functions in favor of using a smarter next() function in while loops.

This commit is contained in:
Joshua Bemenderfer 2023-02-04 09:47:02 -05:00
parent 6cc901fee5
commit f54e29acbf
5 changed files with 98 additions and 285 deletions

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@ -1,6 +1,9 @@
{
"type": "module",
"dependencies": {
"@terrace/core": "0.0.1"
"@terrace/core": "workspace:*"
},
"scripts": {
"example": "node ./parsers/v5/example.js"
}
}

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@ -70,24 +70,55 @@ const lines = [
async function main() {
const { toLineArray } = useDocument(createStringReader(lines))
console.dir(await toLineArray(), { depth: null })
const { head, tail, next, match, level, line } = useDocument(createStringReader(lines))
const { head, tail, each, match, toArray, toObject } = useDocument(createStringReader(lines))
const structure = {}
const structure = await toObject({
'name': true,
'version': () => tail().trim(),
'license': () => tail().trim(),
'exports': () => toObject({
'#any': () => toObject({ import: true, require: true })
}),
'scripts': () => toObject({ '#any': true }),
'devDependencies': () => toObject(),
'authors': () => toArray({
'author': () => toObject({ name: true, email: true, '#text': true })
}),
})
async function kvObject(handle) {
const obj = {}
const l = level()
while (await next(l)) {
if (!head()) continue
obj[head()] = handle ? await handle(level()) : tail().trim()
}
return obj
}
while (await next()) {
if (match('name')) structure.name = tail().trim()
if (match('version')) structure.version = tail().trim()
if (match('exports')) structure.exports = await kvObject(async l => {
const obj = {}
while (await next(l)) {
if (match('import')) obj.import = tail().trim()
if (match('require')) obj.require = tail().trim()
}
return obj
})
if (match('scripts')) structure.scripts = await kvObject()
if (match('devDependencies')) structure.devDependencies = await kvObject()
if (match('author')) {
if (!structure.authors) structure.authors = []
const author = {}
structure.authors.push(author)
const l = level()
while (await next(l)) {
if (!head()) continue
if (match('name')) author.name = tail().trim()
else if (match('email')) author.email = tail().trim()
else {
if (!author['#text']) author['#text'] = [line()]
// Loop through all remaining lines to avoid re-matching name or email above.
while(await next(l)) {
author['#text'].push(line())
}
}
}
}
}
console.dir(structure, { depth: null })
}

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@ -1 +1 @@
"use strict";Object.defineProperties(exports,{__esModule:{value:!0},[Symbol.toStringTag]:{value:"Module"}});const m=require("./parser.cjs");function g(w,b=" "){let c=0;const i=m.createLineData("",b);async function f(){switch(c){case 0:c=1;break;case 2:return c=1,!1}const e=await w.next();return e===null?(c=3,!0):(i.line=e,m.parseLine(i),!1)}const y=()=>c=2,o=()=>i.level,d=()=>i.line.slice(i.offsetHead),u=()=>i.line.slice(i.offsetHead,i.offsetTail),s=()=>i.line.slice(i.offsetTail),j=e=>e===u();async function h(e){const a=c===0?-1:o();for(;;){if(await f())return;if(o()<=a)return y();if(await e())return}}async function p(e=-1,a=[d()]){var n;return e===-1&&(e=o()+1),await f()?a:o()<e?(y(),a):(a.push(((n=i.line)==null?void 0:n.slice(e))||""),p(e,a))}async function x(e={},a=!1){const n=[];let t={};return Object.keys(e).length?Object.keys(e).forEach(r=>{e[r]===!0&&(t[r]={type:a?"collection":"normal",handle:()=>s().trim()}),typeof e[r]=="function"&&(t[r]={type:a?"collection":"normal",handle:e[r]}),typeof e[r]=="object"&&(t[r]=e[r])}):t={"#any":{type:a?"collection":"normal",handle:()=>s().trim()}},await h(async()=>{const r=u();if(!r)return;const l=t[r]||t["#any"];!l||(l.type==="normal"?n.push(await l.handle()):l.type==="collection"&&n.push({[r]:await l.handle()}))}),n}async function O(e={}){const a={};let n={};return Object.keys(e).length?Object.keys(e).forEach(t=>{t==="#tail"?n[t]={type:"tail",handle:()=>{}}:t==="#text"?n[t]={type:"text",handle:()=>{}}:e[t]===!0?n[t]={type:"normal",handle:()=>s().trim()}:typeof e[t]=="function"?n[t]={type:"normal",handle:e[t]}:typeof e[t]=="object"&&(n[t]=e[t])}):n={"#any":{type:"normal",handle:()=>s().trim()}},n["#tail"]&&(a["#tail"]=s().trim()),await h(async()=>{const t=u();if(!t)return;const r=n[t]||n["#any"]||n["#text"];if(!!r&&(r.type==="normal"?a[t]=await r.handle():r.type==="collection"?(a[t]||(a[t]=[]),a[t].push(await r.handle())):r.type==="text"&&(a["#text"]=await p(o())),n&&Object.keys(n).every(l=>["collection"].includes(n[l].type)?!1:a[l]!==void 0)))return!0}),a}async function v(){const e=[["root",[]]];for(;!await f();){const a=o(),n=a+1,t=e[a];if(!t)continue;e.length=n;const r=e[n]=[d(),[]];t[1].push(r)}return e[0]}return{next:f,line:d,head:u,tail:s,level:o,match:j,each:h,blockAsText:p,toObject:O,toArray:x,toLineArray:v}}exports.useDocument=g;
"use strict";Object.defineProperties(exports,{__esModule:{value:!0},[Symbol.toStringTag]:{value:"Module"}});const i=require("./parser.cjs");function f(r,c=" "){const e=i.createLineData("",c);let t=!1;async function o(n=-1){if(t)t=!1;else{const a=await r.next();if(a===null)return!1;e.line=a,i.parseLine(e)}return l()<=n?(t=!0,!1):!0}const l=()=>e.level,u=()=>e.line.slice(e.offsetHead),s=()=>e.line.slice(e.offsetHead,e.offsetTail);return{next:o,level:l,line:u,head:s,tail:()=>e.line.slice(e.offsetTail),match:n=>n===s()}}exports.useDocument=f;

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@ -1,89 +1,28 @@
import { parseLine as v, createLineData as H } from "./parser.js";
function g(y, w = " ") {
let c = 0;
const i = H("", w);
async function s() {
switch (c) {
case 0:
c = 1;
break;
case 2:
return c = 1, !1;
import { parseLine as r, createLineData as u } from "./parser.js";
function h(s, f = " ") {
const e = u("", f);
let t = !1;
async function c(n = -1) {
if (t)
t = !1;
else {
const i = await s.next();
if (i === null)
return !1;
e.line = i, r(e);
}
const e = await y.next();
return e === null ? (c = 3, !0) : (i.line = e, v(i), !1);
}
const p = () => c = 2, o = () => i.level, h = () => i.line.slice(i.offsetHead), u = () => i.line.slice(i.offsetHead, i.offsetTail), f = () => i.line.slice(i.offsetTail), b = (e) => e === u();
async function d(e) {
const a = c === 0 ? -1 : o();
for (; ; ) {
if (await s())
return;
if (o() <= a)
return p();
if (await e())
return;
}
}
async function m(e = -1, a = [h()]) {
var n;
return e === -1 && (e = o() + 1), await s() ? a : o() < e ? (p(), a) : (a.push(((n = i.line) == null ? void 0 : n.slice(e)) || ""), m(e, a));
}
async function j(e = {}, a = !1) {
const n = [];
let t = {};
return Object.keys(e).length ? Object.keys(e).forEach((r) => {
e[r] === !0 && (t[r] = { type: a ? "collection" : "normal", handle: () => f().trim() }), typeof e[r] == "function" && (t[r] = { type: a ? "collection" : "normal", handle: e[r] }), typeof e[r] == "object" && (t[r] = e[r]);
}) : t = { "#any": { type: a ? "collection" : "normal", handle: () => f().trim() } }, await d(async () => {
const r = u();
if (!r)
return;
const l = t[r] || t["#any"];
!l || (l.type === "normal" ? n.push(await l.handle()) : l.type === "collection" && n.push({ [r]: await l.handle() }));
}), n;
}
async function x(e = {}) {
const a = {};
let n = {};
return Object.keys(e).length ? Object.keys(e).forEach((t) => {
t === "#tail" ? n[t] = { type: "tail", handle: () => {
} } : t === "#text" ? n[t] = { type: "text", handle: () => {
} } : e[t] === !0 ? n[t] = { type: "normal", handle: () => f().trim() } : typeof e[t] == "function" ? n[t] = { type: "normal", handle: e[t] } : typeof e[t] == "object" && (n[t] = e[t]);
}) : n = { "#any": { type: "normal", handle: () => f().trim() } }, n["#tail"] && (a["#tail"] = f().trim()), await d(async () => {
const t = u();
if (!t)
return;
const r = n[t] || n["#any"] || n["#text"];
if (!!r && (r.type === "normal" ? a[t] = await r.handle() : r.type === "collection" ? (a[t] || (a[t] = []), a[t].push(await r.handle())) : r.type === "text" && (a["#text"] = await m(o())), n && Object.keys(n).every((l) => ["collection"].includes(n[l].type) ? !1 : a[l] !== void 0)))
return !0;
}), a;
}
async function O() {
const e = [["root", []]];
for (; !await s(); ) {
const a = o(), n = a + 1, t = e[a];
if (!t)
continue;
e.length = n;
const r = e[n] = [h(), []];
t[1].push(r);
}
return e[0];
return l() <= n ? (t = !0, !1) : !0;
}
const l = () => e.level, o = () => e.line.slice(e.offsetHead), a = () => e.line.slice(e.offsetHead, e.offsetTail);
return {
next: s,
line: h,
head: u,
tail: f,
level: o,
match: b,
each: d,
blockAsText: m,
toObject: x,
toArray: j,
toLineArray: O
next: c,
level: l,
line: o,
head: a,
tail: () => e.line.slice(e.offsetTail),
match: (n) => n === a()
};
}
export {
g as useDocument
h as useDocument
};

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@ -1,216 +1,56 @@
import type { Reader } from './readers/reader'
import { createLineData, parseLine } from './parser'
enum STATE {
READY = 0,
STARTED = 1,
PAUSED = 2,
ENDED = 3
}
type Document = {
next: () => Promise<boolean>
export type Document = {
next: (startLevel?: number) => Promise<boolean>
level: () => number,
line: () => string,
head: () => string,
tail: () => string,
match: (matchHead: string) => boolean,
each: (handler: Function) => void,
blockAsText: (startLevel: number, lines?: string[]) => Promise<Array<string>>,
toArray: (inputMatchers: { [key: string]: Function|boolean|{ type: string, handle: Function } }, collection: boolean) => Promise<[{ [key: string]: any }?]>,
toObject: (matchers?: { [key: string]: Function|boolean }) => { [key: string]: any },
toLineArray(): Promise<LineArray>
match: (matchHead: string) => boolean
}
type LineArray = [string, Array<LineArray>]
export function useDocument (reader: Reader, indent: string = ' '): Document {
let state = STATE.READY
const lineData = createLineData('', indent)
async function next() {
switch (state) {
// The initial state change allows us to do some special-case handling for the initial state of lineData. TODO: Should lineData have a special inital state?
case STATE.READY:
state = STATE.STARTED
break
// If we are currently in the "paused" state, repeat the same line instead of reading the next one.
case STATE.PAUSED:
state = STATE.STARTED
return false
let repeat = false
async function next(startLevel: number = -1): Promise<boolean> {
// Repeat the current line instead of parsing a new one if the previous call to next()
// determined the current line to be out of its scope.
if (repeat) repeat = false
// Otherwise parse the line normally.
else {
const line = await reader.next()
// If there are no more lines, bail out.
if (line === null) return false
lineData.line = line
parseLine(lineData)
}
const line = await reader.next()
if (line === null) {
state = STATE.ENDED
return true
// If we shouldn't be handling this line, make the next call to next() repeat the current line.
// Allows a child loop to look forward, determine that the next line will be outside its purview,
// and return control to the calling loop transparently without additional logic.
if (level() <= startLevel) {
repeat = true
return false
}
lineData.line = line
parseLine(lineData)
return false
return true
}
// If we pause, the next call to next() will repeat the current line.
// Allows a child loop to look forward, determine that the next line will be outside its purview,
// and return control to the calling loop transparently without additional logic.
const pause = () => state = STATE.PAUSED
const level = () => lineData.level
const line = () => lineData.line.slice(lineData.offsetHead)
const head = () => lineData.line.slice(lineData.offsetHead, lineData.offsetTail)
const tail = () => lineData.line.slice(lineData.offsetTail)
const match = (matchHead: string): boolean => matchHead === head()
async function each(handler: Function) {
// Set startLevel to -1 if we haven't started parsing the document yet.
// Otherwise we'll break to early, as the default value for doc.level() is 0.
const startLevel = state === STATE.READY ? -1 : level()
while(true) {
if (await next()) return
// If we've reached the next block outside the level of this one, "pause", so that the next time "next" is called, we repeat the same line.
if (level() <= startLevel) return pause()
// If the handler returns true, exit.
if (await handler()) return
}
}
async function blockAsText (startLevel: number = -1, blockLines: string[] = [line()]): Promise<Array<string>> {
if (startLevel === -1) startLevel = level() + 1
if (await next()) return blockLines
if (level() < startLevel) { pause(); return blockLines }
blockLines.push(lineData.line?.slice(startLevel) || '')
return blockAsText(startLevel, blockLines)
}
// Currently a modified copy of toObject. Has lots of room for simplification.
async function toArray (inputMatchers: { [key: string]: Function|boolean|{ type: string, handle: Function } } = {}, collection: boolean = false): Promise<[{ [key: string]: any }?]> {
const arr: [{ [key: string]: any }?] = []
let matchers: { [key: string]: {type: string, handle: Function } } = {}
// Normalize the matchers to an object-based format despite allowing flexible input types for convenience.
// TODO: Decide whether to enforce verbose input once a DSL has been created.
if (!Object.keys(inputMatchers).length) {
// Default matcher
matchers = { '#any': { type: collection ? 'collection' : 'normal', handle: () => tail().trim() } }
} else {
Object.keys(inputMatchers).forEach(key => {
// If a matcher is specified as `true`, treat as a key-value pair where { [head]: tail }
if(inputMatchers[key] === true) matchers[key] = { type: collection ? 'collection' : 'normal', handle: () => tail().trim() }
// If a matcher is specified as a function, treat as a key-value pair where { [head]: handle() }
if (typeof inputMatchers[key] === 'function') matchers[key] = { type: collection ? 'collection' : 'normal', handle: inputMatchers[key] as Function }
// If a matcher is specified as an object, allow customization of the type and handle for various cases.
if (typeof inputMatchers[key] === 'object') matchers[key] = inputMatchers[key] as { type: string, handle: Function }
})
}
await each(async () => {
const currHead = head()
if (!currHead) return
const currMatcher = matchers[currHead] || matchers['#any']
if (!currMatcher) return
// Normal - Outputs values directly into the array, removing their keys.
if (currMatcher.type === 'normal') arr.push(await currMatcher.handle())
// Collection - Outputs values as { head: value } objects into the array, preserving their keys.
else if (currMatcher.type === 'collection') arr.push({ [currHead]: await currMatcher.handle() })
})
return arr
}
async function toObject (inputMatchers: { [key: string]: Function|boolean|{ type: string, handle: Function } } = {}): Promise<{ [key: string]: any }> {
const obj: { [key: string]: any } = {}
let matchers: { [key: string]: {type: string, handle: Function } } = {}
// Normalize the matchers to an object-based format despite allowing flexible input types for convenience.
// TODO: Decide whether to enforce verbose input once a DSL has been created.
if (!Object.keys(inputMatchers).length) {
// Default matcher
matchers = { '#any': { type: 'normal', handle: () => tail().trim() } }
} else {
Object.keys(inputMatchers).forEach(key => {
if (key === '#tail') matchers[key] = { type: 'tail', handle: () => {} }
else if (key === '#text') matchers[key] = { type: 'text', handle: () => {} }
// If a matcher is specified as `true`, treat as a key-value pair where { [head]: tail }
else if (inputMatchers[key] === true) matchers[key] = { type: 'normal', handle: () => tail().trim() }
// If a matcher is specified as a function, treat as a key-value pair where { [head]: handle() }
else if (typeof inputMatchers[key] === 'function') matchers[key] = { type: 'normal', handle: inputMatchers[key] as Function }
// If a matcher is specified as an object, allow customization of the type and handle for various cases.
else if (typeof inputMatchers[key] === 'object') matchers[key] = inputMatchers[key] as { type: string, handle: Function }
})
}
// TODO: Rework this so it fits bettwer with the model already established here.
if (matchers['#tail']) obj['#tail'] = tail().trim()
await each(async () => {
const currHead = head()
if (!currHead) return
const currMatcher = matchers[currHead] || matchers['#any'] || matchers['#text']
if (!currMatcher) return
if (currMatcher.type === 'normal') obj[currHead] = await currMatcher.handle()
// Allows matching the same key more than once.
else if (currMatcher.type === 'collection') {
if (!obj[currHead]) obj[currHead] = []
obj[currHead].push(await currMatcher.handle())
}
// If matchers[currHead] or matchers[#any] is a function, set object key to its output.
// If we get to this point and matchers[#text] is set, parse all remaining block contents as text.
// TODO: I still don't like this.
else if (currMatcher.type === 'text') obj['#text'] = await blockAsText(level())
// Bail early as soon as we know all keys have been matched.
if (matchers && Object.keys(matchers).every(key => {
// If we have any collection keys, we have to continue searching all the way to the end of the current block
// as there may be more than one entry.
if (['collection'].includes(matchers[key].type)) return false
return obj[key] !== undefined
})) return true
})
return obj
}
async function toLineArray (): Promise<LineArray> {
const levelTracker: Array<LineArray> = [['root', []]]
// Simple parser that produces canonical array structure for blocks.
while (true) {
// If next() returns true we've ended the
if (await next()) break
const parentLevel = level()
const scopeLevel = parentLevel + 1
// Determine parent for this scope.
const parent = levelTracker[parentLevel]
// If there's no parent, skip this line.
if (!parent) continue
levelTracker.length = scopeLevel
const scope = levelTracker[scopeLevel] = [line(), []]
// Add current scope to parent.
parent[1].push(scope)
}
return levelTracker[0]
}
return {
next,
level,
line,
head,
tail,
level,
match,
each,
blockAsText,
toObject,
toArray,
toLineArray,
match
}
}