major bug fixes, append number yet to be unit tested
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1 changed files with 76 additions and 74 deletions
146
js/utils.js
146
js/utils.js
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@ -159,46 +159,40 @@ Base64 = (function () {
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/** Constructs an arbitrary-length bit vector.
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* @class
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* @param {String | Number} data
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* @param {Number} length - a set length for the data. Must be in the range [0, 32] if data is a Number.
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* @param {String | Number} data - The data to append.
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* @param {Number} length - A set length for the data. Ignored if data is a string.
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*
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* The structure of the Uint32Array should be [[last, ..., first], ..., [last, ..., first], [empty space, last, ..., first]]
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*/
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constructor(data, length) {
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let bit_vec = [];
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if (length < 0) {
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throw new RangeError("BitVector must have nonnegative length.");
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}
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if (typeof data === "string") {
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//string in B64
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let curr = 0;
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let total_bits = 0;
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let i = 0;
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let int = 0;
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let bv_idx = 0;
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length = data.length * 6;
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//override length passed in if it's > length of string naturally to save space
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length = Math.min(length, data.length * 6);
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while (i < data.length && total_bits < length) {
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let int = Base64.toInt(data[i])
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//total_bits implicitly % 32 here
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curr |= (int << total_bits);
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if (total_bits % 32 > 25) {
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//push and roll over uncaught bits
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bit_vec.push(curr);
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curr = (int >>> (32 - (total_bits % 32)));
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for (let i = 0; i < data.length; i++) {
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let char = Base64.toInt(data[i]);
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let pre_pos = bv_idx % 32;
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int |= (char << bv_idx);
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bv_idx += 6;
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let post_pos = bv_idx % 32;
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if (post_pos < pre_pos) { //we have to have filled up the integer
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bit_vec.push(int);
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int = (char >>> (6 - post_pos));
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}
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i++;
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total_bits += 6;
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}
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//need to push remaining bits if not pushed yet
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if (total_bits % 32 != 0) {
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bit_vec.push(curr);
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if (i == data.length - 1 && post_pos != 0) {
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bit_vec.push(int);
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}
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}
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} else if (typeof data === "number") {
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if (typeof length === "undefined")
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if (length < 0) {
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throw new RangeError("BitVector must have nonnegative length.");
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}
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//convert to int just in case
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data = Math.round(data);
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@ -217,12 +211,12 @@ Base64 = (function () {
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/** Return value of bit at index idx.
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*
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* @param {Number} idx - the index to read
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* @param {Number} idx - The index to read
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*
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* @returns the bit value at position idx
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* @returns The bit value at position idx
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*/
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read_bit(idx) {
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if (idx < 0 || idx > this.length) {
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if (idx < 0 || idx >= this.length) {
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throw new RangeError("Cannot read bit outside the range of the BitVector.");
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}
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return ((this.bits[Math.floor(idx / 32)] & (1 << (idx % 32))) == 0 ? 0 : 1);
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@ -230,10 +224,10 @@ Base64 = (function () {
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/** Returns an integer value (if possible) made from the range of bits [start, end). Undefined behavior if the range to read is too big.
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*
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* @param {Number} start - the index to start slicing from. Inclusive
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* @param {Number} end - the index to end slicing at. Exclusive
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* @param {Number} start - The index to start slicing from. Inclusive.
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* @param {Number} end - The index to end slicing at. Exclusive.
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*
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* @returns an integer representation of the sliced bits.
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* @returns An integer representation of the sliced bits.
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*/
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slice(start, end) {
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//TO NOTE: JS shifting is ALWAYS in mod 32. a << b will do a << (b mod 32) implicitly.
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@ -269,7 +263,7 @@ Base64 = (function () {
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/** Assign bit at index idx to 1.
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*
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* @param {Number} idx - the index to set
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* @param {Number} idx - The index to set.
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*/
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set_bit(idx) {
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if (idx < 0 || idx > this.length) {
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@ -280,7 +274,7 @@ Base64 = (function () {
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/** Assign bit at index idx to 0.
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*
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* @param {Number} idx - the index to clear
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* @param {Number} idx - The index to clear.
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*/
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clear_bit(idx) {
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if (idx < 0 || idx > this.length) {
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@ -291,7 +285,7 @@ Base64 = (function () {
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/** Creates a string version of the bit vector in B64. Does not keep the order of elements a sensible human readable format.
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*
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* @returns a b64 string representation of the BitVector
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* @returns A b64 string representation of the BitVector.
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*/
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toB64() {
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if (this.length == 0) {
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@ -309,7 +303,7 @@ Base64 = (function () {
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/** Returns a BitVector in bitstring format. Probably only useful for dev debugging.
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*
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* @returns a bit string representation of the BitVector. Goes from higher-indexed bits to lower-indexed bits.
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* @returns A bit string representation of the BitVector. Goes from higher-indexed bits to lower-indexed bits. (n ... 0)
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*/
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toString() {
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let ret_str = "";
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@ -319,10 +313,22 @@ Base64 = (function () {
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return ret_str;
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}
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/** Returns a BitVector in bitstring format. Probably only useful for dev debugging.
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*
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* @returns A bit string representation of the BitVector. Goes from lower-indexed bits to higher-indexed bits. (0 ... n)
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*/
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toStringR() {
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let ret_str = "";
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for (let i = 0; i < this.length; i++) {
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ret_str += (this.read_bit(i) == 0 ? "0": "1");
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}
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return ret_str;
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}
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/** Appends data to the BitVector.
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*
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* @param {Number | String} data
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* @param {Number} length - the length, in bits, of the new data
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* @param {Number | String} data - The data to append.
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* @param {Number} length - The length, in bits, of the new data. This is ignored if data is a string.
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*/
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append(data, length) {
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if (length < 0) {
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@ -334,51 +340,47 @@ Base64 = (function () {
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bit_vec.push(uint);
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}
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if (typeof data === "string") {
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//string in B64
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let curr = bit_vec[Math.floor(this.length / 32)];
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let total_bits = this.length;
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let i = 0;
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//override length passed in if it's > length of string naturally to save space
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length = Math.min(length, data.length * 6);
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while (i < data.length && total_bits < this.length + length) {
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let int = Base64.toInt(data[i])
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//total_bits implicitly % 32 here
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curr |= (int << total_bits);
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if (total_bits % 32 > 25) {
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//push and roll over uncaught bits
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if (bit_vec.length == (Math.floor(this.length / 32) + 1)) {
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bit_vec[Math.floor(this.length / 32)] = curr;
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let int = bit_vec[bit_vec.length - 1];
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let bv_idx = this.length;
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length = data.length * 6;
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let updated_curr = false;
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for (let i = 0; i < data.length; i++) {
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let char = Base64.toInt(data[i]);
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let pre_pos = bv_idx % 32;
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int |= (char << bv_idx);
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bv_idx += 6;
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let post_pos = bv_idx % 32;
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if (post_pos < pre_pos) { //we have to have filled up the integer
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if (bit_vec.length == this.bits.length && !updated_curr) {
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bit_vec[bit_vec.length - 1] = int;
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updated_curr = true;
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} else {
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bit_vec.push(curr);
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bit_vec.push(int);
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}
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curr = (int >>> (32 - (total_bits % 32)));
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int = (char >>> (6 - post_pos));
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}
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i++;
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total_bits += 6;
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}
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//need to push remaining bits if not pushed yet
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if (total_bits % 32 != 0) {
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bit_vec.push(curr);
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if (i == data.length - 1) {
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if (bit_vec.length == this.bits.length && !updated_curr) {
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bit_vec[bit_vec.length - 1] = int;
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} else if (post_pos != 0) {
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bit_vec.push(int);
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}
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}
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}
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} else if (typeof data === "number") {
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//convert to int just in case
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let int = Math.round(data);
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//range of numbers that "could" fit in a uint32 -> [0, 2^32) U (-2^31, 2^31)
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if (data > 2**32 - 1 || data < -(2 ** 31 - 1)) {
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//range of numbers that "could" fit in a uint32 -> [0, 2^32) U [-2^31, 2^31)
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if (data > 2**32 - 1 || data < -(2 ** 31)) {
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throw new RangeError("Numerical data has to fit within a 32-bit integer range to instantiate a BitVector.");
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}
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//could be split between multiple new ints
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//reminder that shifts implicitly mod 32
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bit_vec[Math.floor(this.length / 32)] |= ((int & ~((~0) << length)) << (this.length));
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if (Math.floor((this.length + length) / 32) > Math.floor(this.length / 32)) {
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bit_vec.push(int >>> (this.length));
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bit_vec[bit_vec.length - 1] |= ((int & ~((~0) << length)) << (this.length));
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if (((this.length + length) % 32 < ((this.length - 1) % 32) + 1) || ((this.length + length) % 32 != 0)) {
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bit_vec.push(int >>> (32 - this.length));
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}
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} else {
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throw new TypeError("BitVector must be appended with a Number or a B64 String");
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