pxt-common-packages

namespace JSON { export function parseIntRadix(s: string, base?: number) { if (base == null || base == 10) { return parseFloat(s) | 0 } let m = false let r = 0 for (let i = 0; i < s.length; ++i) { let c = s.charCodeAt(i) if (c == 0x20 || c == 10 || c == 13 || c == 9) continue if (r == 0 && !m && c == 0x2d) { m = true continue } let v = -1 if (0x30 <= c && c <= 0x39) v = c - 0x30 else { c |= 0x20 if (0x61 <= c && c <= 0x7a) v = c - 0x61 + 10 } if (0 <= v && v < base) { r *= base r += v } else { return undefined } } return m ? -r : r } class Parser { ptr: number s: string errorMsg: string error(msg: string) { if (!this.errorMsg) { this.errorMsg = msg + " at position " + this.ptr this.ptr = this.s.length } } skipWS() { for (; ;) { const c = this.nextChar() if (c == 0x20 || c == 0x0a || c == 0x0d || c == 0x09) { // OK } else { this.ptr-- return c } } } nextChar() { if (this.ptr < this.s.length) return this.s.charCodeAt(this.ptr++) return 0 } doString() { let r = "" this.ptr++ for (; ;) { const c = this.s.charAt(this.ptr++) if (c == "\"") return r if (c == "\\") { let q = this.s.charAt(this.ptr++) if (q == "b") q = "\b" else if (q == "n") q = "\n" else if (q == "r") q = "\r" else if (q == "t") q = "\t" else if (q == "u") { q = String.fromCharCode(parseIntRadix(this.s.slice(this.ptr, this.ptr + 4), 16)) this.ptr += 4 } r += q } else { r += c } } } doArray(): any[] { const r = [] this.ptr++ for (; ;) { let c = this.skipWS() if (c == 0x5d) { this.ptr++ return r } const v = this.value() if (this.errorMsg) return null r.push(v) c = this.skipWS() if (c == 0x2c) { this.ptr++ continue } if (c == 0x5d) continue this.error("expecting comma") } } doObject() { const r: any = {} this.ptr++ for (; ;) { let c = this.skipWS() if (c == 0x7d) { this.ptr++ return r } if (c != 0x22) { this.error("expecting key") return r } const k = this.doString() c = this.skipWS() if (c != 0x3a) { this.error("expecting colon") return r } this.ptr++ const v = this.value() if (this.errorMsg) return null r[k] = v c = this.skipWS() if (c == 0x2c) { this.ptr++ continue } if (c == 0x7d) continue this.error("expecting comma, got " + String.fromCharCode(c)) } } doNumber() { const beg = this.ptr for (; ;) { const c = this.nextChar() if ((0x30 <= c && c <= 0x39) || c == 0x2b || c == 0x2d || c == 0x2e || c == 0x45 || c == 0x65) { // one more } else { this.ptr-- break } } const ss = this.s.slice(beg, this.ptr) if (ss.length == 0) { this.error("expecting number") return 0 } return parseFloat(ss) } checkKw(k: string) { if (this.s.slice(this.ptr, this.ptr + k.length) == k) { this.ptr += k.length return true } return false } value() { if (this.errorMsg) return null const c = this.skipWS() if (c == 0x7b) return this.doObject() else if (c == 0x5b) return this.doArray() else if ((0x30 <= c && c <= 0x39) || c == 0x2d) return this.doNumber() else if (c == 0x22) return this.doString() else if (c == 0x74 && this.checkKw("true")) return true else if (c == 0x66 && this.checkKw("false")) return false else if (c == 0x6e && this.checkKw("null")) return null this.error("unexpected token") return null } } class Stringifier { currIndent: string indentStep: string indent: number doString(s: string) { let r = "\"" for (let i = 0; i < s.length; ++i) { let c = s[i] if (c == "\n") c = "\\n" else if (c == "\r") c = "\\r" else if (c == "\t") c = "\\t" else if (c == "\b") c = "\\b" else if (c == "\\") c = "\\\\" else if (c == "\"") c = "\\\"" r += c } return r + "\"" } go(v: any) { const t = typeof v if (t == "string") return this.doString(v) else if (t == "boolean" || t == "number" || v == null) return "" + v else if (Array.isArray(v)) { const arr = v as any[] if (arr.length == 0) return "[]" else { let r = "[" if (this.indent) { this.currIndent += this.indentStep r += "\n" } for (let i = 0; i < arr.length; ++i) { r += this.currIndent + this.go(arr[i]) if (i != arr.length - 1) r += "," if (this.indent) r += "\n" } if (this.indent) this.currIndent = this.currIndent.slice(this.indent) r += this.currIndent + "]" return r } } else { const keys = Object.keys(v) if (keys.length == 0) return "{}" let r = "{" if (this.indent) { this.currIndent += this.indentStep r += "\n" } for (let i = 0; i < keys.length; ++i) { const k = keys[i] r += this.currIndent + this.doString(k) if (this.indent) r += ": " else r += ":" r += this.go(v[k]) if (i != keys.length - 1) r += "," if (this.indent) r += "\n" } if (this.indent) this.currIndent = this.currIndent.slice(this.indent) r += this.currIndent + "}" return r } } } /** * Converts a JavaScript value to a JavaScript Object Notation (JSON) string. * @param value A JavaScript value, usually an object or array, to be converted. * @param replacer Not supported; use null. * @param indent Adds indentation, white space, and line break characters to the return-value JSON text to make it easier to read. */ export function stringify(value: any, replacer: any = null, indent: number = 0) { const ss = new Stringifier() ss.currIndent = "" indent |= 0 if (indent < 0) indent = 0 if (indent > 10) indent = 10 ss.indentStep = "" ss.currIndent = "" ss.indent = indent while (indent-- > 0) ss.indentStep += " " return ss.go(value) } /** * Converts a JavaScript Object Notation (JSON) string into an object. * @param text A valid JSON string. */ export function parse(s: string) { const p = new Parser() p.ptr = 0 p.s = s const r = p.value() if (p.skipWS()) { p.error("excessive input") } if (p.errorMsg) { control.dmesg("Invalid JSON: " + p.errorMsg) return undefined } return r } }