new built-in keysof and rewrote the json parser
This commit is contained in:
cozis
+286
-206
@@ -1,240 +1,320 @@
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Scanner = {src: String, i: int};
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fun newScanner(src: String) {
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scan = {src: src, i: 0};
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assert(istypeof(Scanner, scan));
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return scan;
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}
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fun isDigit(char: ?String) {
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if char == none:
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return false;
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return string.ord(char) >= string.ord('0')
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and string.ord(char) <= string.ord('9');
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}
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fun isSpace(c: String)
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return c == " "
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or c == "\t"
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or c == "\n";
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return c == ' '
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or c == '\t'
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or c == '\n';
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fun isDigit(c: String) {
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d = string.ord(c)
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- string.ord("0");
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return d >= 0
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and d <= 9;
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fun min(x, y) {
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if x < y:
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return x;
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return y;
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}
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ParsingContext = {str: String, cur: int};
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fun skipSpaces(context: ParsingContext) {
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# Skip zero or more whitespace characters.
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while context.cur < count(context.str)
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and isSpace(context.str[context.cur]):
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context.cur = context.cur + 1;
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}
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fun parseNull(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and context.str[context.cur] == 'n');
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if context.cur+3 > count(context.str)
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or context.str[context.cur+1] != 'u'
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or context.str[context.cur+2] != 'l'
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or context.str[context.cur+3] != 'l':
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return none, "Unexpected token starting with \"n\"";
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context.cur = context.cur + count("null");
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fun hint(scan: Scanner, n: int = 1) {
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k = scan.i + n;
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if k < count(scan.src):
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return scan.src[k];
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return none;
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}
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fun parseTrue(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and context.str[context.cur] == 't');
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if context.cur+3 > count(context.str)
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or context.str[context.cur+1] != 'r'
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or context.str[context.cur+2] != 'u'
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or context.str[context.cur+3] != 'e':
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return none, "Unexpected token starting with \"t\"";
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context.cur = context.cur + count("true");
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return true;
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fun current(scan: Scanner)
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return hint(scan, 0);
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fun consume(scan: Scanner, n: int = 1) {
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assert(n > 0);
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limit = count(scan.src);
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scan.i = min(scan.i + n, limit);
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}
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fun parseFalse(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and context.str[context.cur] == 'f');
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if context.cur+3 > count(context.str)
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or context.str[context.cur+1] != 'a'
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or context.str[context.cur+2] != 'l'
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or context.str[context.cur+3] != 's'
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or context.str[context.cur+4] != 'e':
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return none, "Unexpected token starting with \"f\"";
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context.cur = context.cur + count("false");
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return false;
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}
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fun consumeSpaces(scan: Scanner)
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while isSpace(current(scan)):
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consume(scan);
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fun dummy() {}
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Func = type(dummy);
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fun parseString(scan: Scanner) {
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fun skip(context: ParsingContext, test_callback: Func) {
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k = context.cur;
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while k < count(context.str)
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and test_callback(context.str[k]):
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k = k + 1;
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return k;
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}
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assert(current(scan) == '"');
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consume(scan); # Consume the opening "
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fun parseInteger(context: ParsingContext) {
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assert(context.cur < count(context.str) and isDigit(context.str[context.cur]));
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buffer = 0;
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do {
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c = context.str[context.cur];
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d = string.ord(c) - string.ord('0');
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buffer = buffer * 10 + d;
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context.cur = context.cur + 1;
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} while context.cur < count(context.str)
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and isDigit(context.str[context.cur]);
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return buffer;
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}
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fun parseFloating(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and isDigit(context.str[context.cur]));
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# It's ensured by the caller (parseIntegerOrFloating)
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# that now the strings contains two sequences of
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# digits with a dot in the middle.
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buffer = 0.0;
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# Scan the integer part.
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do {
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c = context.str[context.cur];
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d = string.ord(c) - string.ord('0');
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buffer = buffer * 10 + d;
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context.cur = context.cur + 1;
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} while context.str[context.cur] != ".";
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assert(isDigit(context.str[context.cur+1]));
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# Scan the decimal part.
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q = 1;
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do {
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c = context.str[context.cur];
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d = string.ord(c) - string.ord('0');
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q = q / 10;
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buffer = buffer + q * d;
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context.cur = context.cur + 1;
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} while context.cur < count(context.str)
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and isDigit(context.str[context.cur+1]);
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return buffer;
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}
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fun parseIntegerOrFloating(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and isDigit(context.str[context.cur]));
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# Is the first digit sequence followed by a dot
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# and then one or more digits?
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k = skip(context, isDigit);
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if k+1 < count(context.str) and context.str[k] == "." and isDigit(context.str[k+1]):
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# It's a floating point value, then!
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return parseFloating(context);
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else
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# It's good old integer!
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return parseInteger(context);
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}
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fun parseString(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and context.str[context.cur] == '"');
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context.cur = context.cur + 1;
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buffer = "";
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while context.cur < count(context.str)
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and context.str[context.cur] != '"': {
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# TODO: Support special characters such as \n, \t ecc
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buffer = string.cat(buffer, context.str[context.cur]);
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context.cur = context.cur + 1;
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temp = "";
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char = current(scan);
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while char != '"' and char != none: {
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temp = string.cat(temp, char);
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consume(scan);
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char = current(scan);
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}
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if context.cur == count(context.str):
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return none, "Source string ended inside a string literal";
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if char == none: {
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val = none;
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err = "Source ended inside a string literal";
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} else {
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assert(char == '"');
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consume(scan);
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val = temp;
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err = none;
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}
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context.cur = context.cur + 1;
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return buffer;
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return val, err;
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}
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fun parseArray(context: ParsingContext) {
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assert(context.cur < count(context.str)
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and context.str[context.cur] == '[');
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fun parseObject(scan: Scanner) {
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assert(current(scan) == '{');
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consume(scan);
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context.cur = context.cur + 1;
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obj = {};
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consumeSpaces(scan);
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if current(scan) != '}': do {
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key, err = parseValue(scan);
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if err != none:
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return none, err;
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if type(key) != String:
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return none, "Object key isn't a string";
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skipSpaces(context);
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consumeSpaces(scan);
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if current(scan) != ':':
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return none, "Missing ':' separator after key";
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consume(scan);
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if context.cur == count(context.str):
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return none, "Source string ended inside an array";
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if context.str[context.cur] == ']':
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return [];
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list = [];
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while true: {
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item, err = parseValue(context);
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val, err = parseValue(scan);
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if err != none:
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return none, err;
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list[count(list)] = item;
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if obj[key] != none:
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return none, "Duplicate key in object";
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obj[key] = val;
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skipSpaces(context);
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if context.cur == count(context.str):
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return none, "Source string ended inside an array";
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if context.str[context.cur] == ']':
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break;
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if context.str[context.cur] != ',':
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return none, "Unexpected token inside an array, where either ',' or ']' were expected";
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context.cur = context.cur + 1;
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skipSpaces(context);
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}
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assert(context.cur < count(context.str)
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and context.str[context.cur] == ']');
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context.cur = context.cur + 1;
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return list;
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consumeSpaces(scan);
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if current(scan) == '}':
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done = true;
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else {
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if current(scan) != ',':
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return none, "Invalid character where either ',' or '}' were expected";
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consume(scan); # Consume the ","
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done = false;
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}
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} while not done;
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assert(current(scan) == '}');
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consume(scan);
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return obj;
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}
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fun parseValue(context: ParsingContext) {
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fun parseArray(scan: Scanner) {
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if context.cur == count(context.str):
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return none, "Source ended where a value was expected";
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assert(current(scan) == '[');
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consume(scan); # Consume the [
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array = [];
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consumeSpaces(scan);
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if current(scan) != ']': do {
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c = context.str[context.cur];
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if c == "{": val, err = parseObject(context);
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else if c == "[": val, err = parseArray(context);
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else if c == '"': val, err = parseString(context);
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else if isDigit(c): val, err = parseIntegerOrFloating(context);
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else if c == 'n': val, err = parseNull(context);
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else if c == 't': val, err = parseTrue(context);
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else if c == 'f': val, err = parseFalse(context);
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else {
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val = none;
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err = string.cat("Unexepected character \"", c, "\" where a value was expected");
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val, err = parseValue(scan);
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if err != none:
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return none, err;
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array[count(array)] = val;
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consumeSpaces(scan);
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if current(scan) == ']':
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done = true;
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else {
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if current(scan) != ',':
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return none, "Invalid character where either ',' or ']' were expected";
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consume(scan); # Consume the ","
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done = false;
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}
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} while not done;
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assert(current(scan) == ']');
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consume(scan);
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return array;
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}
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fun parseFalse(scan: Scanner) {
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assert(current(scan) == 'f');
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consume(scan);
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if current(scan) != 'a':
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return none, "Invalid character after 'f'";
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consume(scan);
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if current(scan) != 'l':
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return none, "Invalid character after 'fa'";
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consume(scan);
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if current(scan) != 's':
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return none, "Invalid character after 'fal'";
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consume(scan);
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if current(scan) != 'e':
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return none, "Invalid character after 'fals'";
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consume(scan);
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return false;
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}
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fun parseTrue(scan: Scanner) {
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assert(current(scan) == 't');
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consume(scan);
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if current(scan) != 'r':
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return none, "Invalid character after 't'";
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consume(scan);
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if current(scan) != 'u':
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return none, "Invalid character after 'tr'";
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consume(scan);
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if current(scan) != 'e':
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return none, "Invalid character after 'tru'";
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consume(scan);
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return true;
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}
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fun parseNull(scan: Scanner) {
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assert(current(scan) == 'n');
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consume(scan);
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if current(scan) != 'u':
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return none, "Invalid character after 'n'";
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consume(scan);
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if current(scan) != 'l':
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return none, "Invalid character after 'nu'";
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consume(scan);
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if current(scan) != 'l':
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return none, "Invalid character after 'nul'";
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consume(scan);
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return none;
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}
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fun integerFromDigit(char: String) {
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assert(count(char) == 1);
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return string.ord(char)
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- string.ord('0');
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}
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fun parseNumber(scan: Scanner) {
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char = current(scan);
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sign = 1;
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if char == '+' or char == '-': {
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sign = {'+': 1, '-': -1}[char];
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consume(scan);
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char = current(scan);
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if not isDigit(char):
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return none, "Invalid character after +/-";
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}
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temp = 0.0;
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do {
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assert(isDigit(char));
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n = integerFromDigit(char);
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temp = temp * 10 + n;
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consume(scan);
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char = current(scan);
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} while isDigit(char);
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if char == '.' and isDigit(hint(scan, 1)): {
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consume(scan); # Consume the dot
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char = current(scan);
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q = 1.0;
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do {
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q = q / 10;
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n = integerFromDigit(char);
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temp = temp + q * n;
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consume(scan);
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char = current(scan);
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} while isDigit(char);
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}
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return sign * temp;
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}
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fun parseValue(scan: Scanner) {
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table = {
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'"': parseString,
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'{': parseObject,
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'[': parseArray,
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'f': parseFalse,
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't': parseTrue,
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'n': parseNull,
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'+': parseNumber,
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'-': parseNumber,
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'0': parseNumber,
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'1': parseNumber,
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'2': parseNumber,
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'3': parseNumber,
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'4': parseNumber,
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'5': parseNumber,
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'6': parseNumber,
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'7': parseNumber,
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'8': parseNumber,
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'9': parseNumber
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};
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consumeSpaces(scan);
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char = current(scan);
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if char == none: {
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val = none;
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err = "Source ended where a value was expected";
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} else {
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callback = table[char];
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if callback == none: {
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val = none;
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err = "Invalid character where a value was expected";
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} else
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(val, err) = callback(scan);
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}
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return (val, err);
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}
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fun parse(src: String) {
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scan = newScanner(src);
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val, err = parseValue(scan);
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return val, err;
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}
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fun parse(str: String) {
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context = {str: str, cur: 0};
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skipSpaces(context);
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val, err = parseValue(context);
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return val, err;
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fun parseFile(file: String | File) {
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if type(file) == String: {
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file, err = files.open(file, files.READ);
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if err != none:
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return none, err;
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}
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src, err = files.read(file);
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if err != none:
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return none, err;
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assert(type(src) == String);
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val, err = parse(src);
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return val, err;
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}
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Block a user