// Read until the end_str is found, store all characters (not including end_str) in m_buffer.
// Throw a parser exception error_msg if end of file is found before end_str.
void scanner::read_until(char const * end_str, char const * error_msg) {
lean_assert(end_str);
lean_assert(end_str[0]);
m_buffer.clear();
while (true) {
check_not_eof(error_msg);
char c = curr_next();
if (c == end_str[0]) {
m_aux_buffer.clear();
m_aux_buffer += c;
unsigned i = 1;
while (true) {
if (!end_str[i])
return;
check_not_eof(error_msg);
c = curr_next();
if (c != end_str[i]) {
m_buffer += m_aux_buffer;
break;
}
i++;
}
} else {
m_buffer += c;
}
}
}
void scanner::read_doc_block_core() {
m_buffer.clear();
while (true) {
check_not_eof("unexpected end of documentation block");
char c = curr();
next();
if (c == '-') {
if (curr() == '/') {
next();
return;
}
}
m_buffer += c;
}
}
void scanner::read_comment_block() {
unsigned nesting = 1;
while (true) {
char c = curr();
check_not_eof("unexpected end of comment block");
next();
if (c == '/') {
if (curr() == '-') {
next();
nesting++;
}
} else if (c == '-') {
if (curr() == '/') {
next();
nesting--;
if (nesting == 0)
return;
}
}
}
}
char scanner::read_quoted_char(char const * error_msg) {
lean_assert(curr() == '\\');
next();
check_not_eof(error_msg);
char c = curr();
if (c != '\\' && c != '\"' && c != 'n' && c != '\'' && c != 'x')
throw_exception("invalid escape sequence");
if (c == 'n') {
return '\n';
} else if (c == 'x') {
next();
char c = curr();
unsigned v = hex_to_unsigned(c);
next();
c = curr();
v = 16*v + hex_to_unsigned(c);
return static_cast<char>(v);
} else {
return c;
}
}