Files
Noja/examples/json.noja
T
2022-12-07 23:48:16 +01:00

346 lines
8.5 KiB
Plaintext

scan = import("scan.noja");
newScanner = scan.newScanner;
Scanner = scan.Scanner;
hint = scan.hint;
consume = scan.consume;
current = scan.current;
consumeSpaces = scan.consumeSpaces;
isDigit = scan.isDigit;
fun parseString(scan: Scanner) {
assert(current(scan) == '"');
consume(scan); # Consume the opening "
temp = "";
char = current(scan);
while char != '"' and char != none: {
temp = string.cat(temp, char);
consume(scan);
char = current(scan);
}
if char == none: {
val = none;
err = "Source ended inside a string literal";
} else {
assert(char == '"');
consume(scan);
val = temp;
err = none;
}
return val, err;
}
fun parseObject(scan: Scanner) {
assert(current(scan) == '{');
consume(scan);
obj = {};
consumeSpaces(scan);
if current(scan) != '}': do {
key, err = parseValue(scan);
if err != none:
return none, err;
if type(key) != String:
return none, "Object key isn't a string";
consumeSpaces(scan);
if current(scan) != ':':
return none, "Missing ':' separator after key";
consume(scan);
val, err = parseValue(scan);
if err != none:
return none, err;
if obj[key] != none:
return none, "Duplicate key in object";
obj[key] = val;
consumeSpaces(scan);
if current(scan) == '}':
done = true;
else {
if current(scan) != ',':
return none, "Invalid character where either ',' or '}' were expected";
consume(scan); # Consume the ","
done = false;
}
} while not done;
assert(current(scan) == '}');
consume(scan);
return obj;
}
fun parseArray(scan: Scanner) {
assert(current(scan) == '[');
consume(scan); # Consume the [
array = [];
consumeSpaces(scan);
if current(scan) != ']': do {
val, err = parseValue(scan);
if err != none:
return none, err;
array[count(array)] = val;
consumeSpaces(scan);
if current(scan) == ']':
done = true;
else {
if current(scan) != ',':
return none, "Invalid character where either ',' or ']' were expected";
consume(scan); # Consume the ","
done = false;
}
} while not done;
assert(current(scan) == ']');
consume(scan);
return array;
}
fun parseFalse(scan: Scanner) {
assert(current(scan) == 'f');
consume(scan);
if current(scan) != 'a':
return none, "Invalid character after 'f'";
consume(scan);
if current(scan) != 'l':
return none, "Invalid character after 'fa'";
consume(scan);
if current(scan) != 's':
return none, "Invalid character after 'fal'";
consume(scan);
if current(scan) != 'e':
return none, "Invalid character after 'fals'";
consume(scan);
return false;
}
fun parseTrue(scan: Scanner) {
assert(current(scan) == 't');
consume(scan);
if current(scan) != 'r':
return none, "Invalid character after 't'";
consume(scan);
if current(scan) != 'u':
return none, "Invalid character after 'tr'";
consume(scan);
if current(scan) != 'e':
return none, "Invalid character after 'tru'";
consume(scan);
return true;
}
fun parseNull(scan: Scanner) {
assert(current(scan) == 'n');
consume(scan);
if current(scan) != 'u':
return none, "Invalid character after 'n'";
consume(scan);
if current(scan) != 'l':
return none, "Invalid character after 'nu'";
consume(scan);
if current(scan) != 'l':
return none, "Invalid character after 'nul'";
consume(scan);
return none;
}
fun integerFromDigit(char: String) {
assert(count(char) == 1);
return string.ord(char)
- string.ord('0');
}
fun parseNumber(scan: Scanner) {
char = current(scan);
sign = 1;
if char == '+' or char == '-': {
sign = {'+': 1, '-': -1}[char];
consume(scan);
char = current(scan);
if not isDigit(char):
return none, "Invalid character after +/-";
}
temp = 0.0;
do {
assert(isDigit(char));
n = integerFromDigit(char);
temp = temp * 10 + n;
consume(scan);
char = current(scan);
} while isDigit(char);
if char == '.' and isDigit(hint(scan, 1)): {
consume(scan); # Consume the dot
char = current(scan);
q = 1.0;
do {
q = q / 10;
n = integerFromDigit(char);
temp = temp + q * n;
consume(scan);
char = current(scan);
} while isDigit(char);
}
return sign * temp;
}
fun parseValue(scan: Scanner) {
table = {
'"': parseString,
'{': parseObject,
'[': parseArray,
'f': parseFalse,
't': parseTrue,
'n': parseNull,
'+': parseNumber,
'-': parseNumber,
'0': parseNumber,
'1': parseNumber,
'2': parseNumber,
'3': parseNumber,
'4': parseNumber,
'5': parseNumber,
'6': parseNumber,
'7': parseNumber,
'8': parseNumber,
'9': parseNumber
};
consumeSpaces(scan);
char = current(scan);
if char == none: {
val = none;
err = "Source ended where a value was expected";
} else {
callback = table[char];
if callback == none: {
val = none;
err = "Invalid character where a value was expected";
} else
(val, err) = callback(scan);
}
return (val, err);
}
fun parse(src: String) {
scan = newScanner(src);
val, err = parseValue(scan);
return val, err;
}
fun test() {
compareAny = import("compare.noja").compareAny;
Error = String;
JSONValueType = (bool | float | String | Map | List | None);
TestCase = [String, ?JSONValueType, ?Error];
fun runAllTestCases(test_cases: List) {
total = count(test_cases);
passed = 0;
evaluated = 0;
while evaluated < total: {
test_case = test_cases[evaluated];
input = test_case[0];
expres = test_case[1]; # Expected result
experr = test_case[2]; # Expected error
res, err = parse(input);
#print("res=", res, ", err=", err, "\n");
#print("expres=", expres, ", experr=", experr, "\n");
result = compareAny(res, expres)
and compareAny(err, experr);
if result: {
print("Test ", evaluated, ": PASSED\n");
passed = passed+1;
} else {
print("Test ", evaluated, ": FAILED\n");
print("\tInput:\n");
print("\t\t", input, "\n");
if experr == none: {
if err == none:
print("\tGot result ", res, " but was expected ", expres, "\n");
else
print("\tFailed unexpectedly [", err, "]\n");
} else if err == none:
print("\tSucceded unexpectedly. Was expected error [", experr, "]\n");
else
print("\tWas expected error [", experr, "], but got [", err, "]\n");
}
evaluated = evaluated+1;
}
return passed, (total-passed), total;
}
fun newPassingTestCase(src: String, res: JSONValueType)
return [src, res, none];
fun newFailingTestCase(src: String, err: String)
return [src, none, err];
test_cases = [
newPassingTestCase("null", none),
newPassingTestCase("true", true),
newPassingTestCase("false", false),
newPassingTestCase("\"Hello, world!\"", "Hello, world!"),
newPassingTestCase("1", 1.0),
newPassingTestCase("2.3", 2.3),
newPassingTestCase("[]", []),
newPassingTestCase("[1]", [1.0]),
newPassingTestCase("[1, 2]", [1.0, 2.0]),
newPassingTestCase("[1, 2, 3]", [1.0, 2.0, 3.0]),
newPassingTestCase("{}", {}),
newPassingTestCase("{\"k1\": true}", {k1: true}),
newPassingTestCase("{\"k1\": true, \"k2\": false}", {k1: true, k2: false})
];
passed, failed, total = runAllTestCases(test_cases);
print("passed: ", passed, "\n");
print("failed: ", failed, "\n");
print(" total: ", total, "\n");
}