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//: Support literal non-integers.
:(scenarios load)
:(scenario noninteger_literal)
def main [
1:number <- copy 3.14159
]
+parse: ingredient: {3.14159: "literal-fractional-number"}
:(after "Parsing reagent(string s)")
if (is_noninteger(s)) {
name = s;
type = new type_tree("literal-fractional-number", 0);
set_value(to_double(s));
return;
}
:(code)
bool is_noninteger(const string& s) {
return s.find_first_not_of("0123456789-.") == string::npos // no other characters
&& s.find_first_of("0123456789") != string::npos // at least one digit
&& s.find('-', 1) == string::npos // '-' only at first position
&& std::count(s.begin(), s.end(), '.') == 1; // exactly one decimal point
}
double to_double(string n) {
char* end = NULL;
// safe because string.c_str() is guaranteed to be null-terminated
double result = strtod(n.c_str(), &end);
assert(*end == '\0');
return result;
}
void test_is_noninteger() {
CHECK(!is_noninteger("1234"));
CHECK(!is_noninteger("1a2"));
CHECK(is_noninteger("234.0"));
CHECK(!is_noninteger("..."));
CHECK(!is_noninteger("."));
CHECK(is_noninteger("2."));
CHECK(is_noninteger(".2"));
CHECK(is_noninteger("-.2"));
CHECK(is_noninteger("-2."));
CHECK(!is_noninteger("--.2"));
CHECK(!is_noninteger(".-2"));
CHECK(!is_noninteger("..2"));
}
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