use crate::lexers::Token;
pub struct Lexer {
input: Vec<char>,
pub position: usize,
pub read_position: usize,
pub ch: char,
}
fn is_letter(ch: char) -> bool {
ch.is_alphabetic() || ch == '_'
}
impl Lexer {
pub fn new(input: Vec<char>) -> Self {
Self {
input,
position: 0,
read_position: 0,
ch: '\0',
}
}
pub fn read_char(&mut self) {
if self.read_position >= self.input.len() {
self.ch = '\0';
} else {
self.ch = self.input[self.read_position];
}
self.position = self.read_position;
self.read_position += 1;
}
pub fn next_token(&mut self) -> Token {
let read_identifier = |l: &mut Lexer| -> Vec<char> {
let position = l.position;
while l.position < l.input.len() && is_letter(l.ch) {
l.read_char();
}
l.input[position..l.position].to_vec()
};
let read_string = |l: &mut Lexer, ch: char| -> Vec<char> {
let position = l.position;
l.read_char();
while l.position < l.input.len() && l.ch != ch {
if l.ch == '\\' {
l.read_char();
}
l.read_char();
}
l.read_char();
if l.position > l.input.len() {
l.position -= 1;
l.read_position -= 1;
}
l.input[position..l.position].to_vec()
};
let read_number = |l: &mut Lexer| -> Vec<char> {
let position = l.position;
while l.position < l.input.len() && l.ch.is_numeric() {
l.read_char();
}
l.input[position..l.position].to_vec()
};
let tok: Token;
if self.ch == '/' {
let next_id = String::from("/*").chars().collect::<Vec<_>>();
let next_position = self.position + next_id.len();
let end_id = String::from("*/").chars().collect::<Vec<_>>();
if self.position + next_id.len() < self.input.len()
&& self.input[self.position..next_position] == next_id
{
let mut identifier = next_id.clone();
next_id.iter().for_each(|_| self.read_char());
let start_position = self.position;
while self.position < self.input.len() {
if self.ch == '*' {
let end_position = self.position + end_id.len();
if end_position <= self.input.len()
&& self.input[self.position..end_position] == end_id
{
end_id.to_owned().iter().for_each(|_| self.read_char());
break;
}
}
self.read_char();
}
identifier.append(&mut self.input[start_position..self.position].to_vec());
return Token::COMMENT(identifier);
}
}
if self.read_position < self.input.len()
&& self.ch == '='
&& self.input[self.read_position] == '='
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec!['=', '=']);
}
if self.read_position < self.input.len()
&& self.ch == '>'
&& self.input[self.read_position] == '>'
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec!['>', '>']);
}
if self.read_position < self.input.len()
&& self.ch == ':'
&& self.input[self.read_position] == '='
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec![':', '=']);
}
if self.read_position < self.input.len()
&& self.ch == '/'
&& self.input[self.read_position] == '/'
{
return Token::COMMENT(read_string(self, '\n'));
}
if self.read_position < self.input.len()
&& self.ch == '='
&& self.input[self.read_position] == '='
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec!['=', '=']);
}
if self.read_position < self.input.len()
&& self.ch == '>'
&& self.input[self.read_position] == '>'
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec!['>', '>']);
}
if self.read_position < self.input.len()
&& self.ch == ':'
&& self.input[self.read_position] == '='
{
self.read_char();
self.read_char();
return Token::KEYWORD(vec![':', '=']);
}
match self.ch {
'\n' => {
tok = Token::ENDL(self.ch);
}
'\0' => {
tok = Token::EOF;
}
'0' => {
return if self.input[self.read_position] == 'x' {
let start_position = self.position;
self.read_char();
self.read_char();
while self.position < self.input.len()
&& (self.ch.is_numeric() || is_letter(self.ch))
{
self.read_char();
}
let hexadecimal = &self.input[start_position..self.position];
Token::INT(hexadecimal.to_vec())
} else {
let number = read_number(self);
Token::INT(number)
}
}
'&' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'*' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'<' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'>' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'-' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'=' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'|' => {
tok = Token::KEYWORD(vec![self.ch]);
}
'+' => {
tok = Token::KEYWORD(vec![self.ch]);
}
_ => {
return if is_letter(self.ch) {
#[allow(unused_variables)]
let start_position = self.position;
#[allow(unused_mut)]
let mut identifier: Vec<char> = read_identifier(self);
if self.ch.is_numeric() {
let position = self.position;
while self.position < self.input.len() {
if !self.ch.is_numeric() && !is_letter(self.ch) {
break;
}
self.read_char();
}
identifier.append(&mut self.input[position..self.position].to_vec());
}
match get_keyword_token(&identifier) {
Ok(keyword_token) => keyword_token,
Err(_) => {
if self.ch == '(' {
return Token::ENTITY(identifier);
} else if self.ch.is_whitespace() {
let mut position = self.position;
let mut ch = self.input[position];
while position < self.input.len() && ch.is_whitespace() {
position += 1;
if position < self.input.len() {
ch = self.input[position];
}
}
if ch == '(' {
return Token::ENTITY(identifier);
}
}
if self.ch == ']' {
return Token::ENTITY(identifier);
} else if self.ch.is_whitespace() {
let mut position = self.position;
let mut ch = self.input[position];
while position < self.input.len() && ch.is_whitespace() {
position += 1;
if position < self.input.len() {
ch = self.input[position];
}
}
if ch == ']' {
return Token::ENTITY(identifier);
}
}
Token::IDENT(identifier)
}
}
} else if self.ch.is_numeric() {
let identifier: Vec<char> = read_number(self);
Token::INT(identifier)
} else if self.ch == '\'' {
let str_value: Vec<char> = read_string(self, '\'');
Token::STRING(str_value)
} else if self.ch == '"' {
let str_value: Vec<char> = read_string(self, '"');
Token::STRING(str_value)
} else {
Token::ILLEGAL
}
}
}
self.read_char();
tok
}
}
pub fn get_keyword_token(identifier: &Vec<char>) -> Result<Token, String> {
let id: String = identifier.into_iter().collect();
match &id[..] {
"true" | "false" | "None" => Ok(Token::CONSTANT(identifier.clone())),
"fn" | "import" | "return" | "pub" | "mut" | "bool" | "string" | "i8" | "i16" | "int"
| "i64" | "byte" | "u16" | "u32" | "u64" | "rune" | "f32" | "f64" | "isize" | "usize"
| "voidptr" | "any" | "assert" | "struct" | "type" | "in" | "it" | "if" | "else"
| "typeof" | "map" | "as" | "is" | "match" | "enum" | "defer" | "for" | "continue"
| "break" | "unsafe" | "const" | "module" | "interface" | "or" | "go" | "chan"
| "select" | "share" | "lock" | "rlock" | "heap" | "__offsetof" | "union" | "asm"
| "goto" | "static" | "embed" => Ok(Token::KEYWORD(identifier.clone())),
_ => Err(String::from("Not a keyword")),
}
}
pub fn render_html(input: Vec<char>) -> String {
let mut l = Lexer::new(input);
l.read_char();
let mut html = String::new();
let mut line = 1;
html.push_str("<table class=\"highlight-table\">\n");
html.push_str("<tbody>\n");
html.push_str("<tr>");
html.push_str(&format!(
"<td class=\"hl-num\" data-line=\"{}\"></td><td>",
line
));
loop {
let token = l.next_token();
if token == Token::EOF {
html.push_str("</td></tr>\n");
break;
}
match token {
Token::INT(value) => {
html.push_str(&format!(
"<span class=\"hl-c\">{}</span>",
value.iter().collect::<String>()
));
}
Token::IDENT(value) => {
html.push_str(&value.iter().collect::<String>());
}
Token::STRING(value) => {
let mut s = String::new();
for ch in value {
if ch == '<' {
s.push_str("<");
} else if ch == '>' {
s.push_str(">");
} else {
s.push(ch);
}
}
html.push_str(&format!("<span class=\"hl-s\">{}</span>", s));
}
Token::ENTITY(value) => {
html.push_str(&format!(
"<span class=\"hl-en\">{}</span>",
value.iter().collect::<String>()
));
}
Token::CONSTANT(value) => {
html.push_str(&format!(
"<span class=\"hl-c\">{}</span>",
value.iter().collect::<String>()
));
}
Token::KEYWORD(value) => {
html.push_str(&format!(
"<span class=\"hl-k\">{}</span>",
value.iter().collect::<String>()
));
}
Token::COMMENT(value) => {
let mut lines = String::new();
for ch in value {
if ch == '<' {
lines.push_str("<");
} else if ch == '>' {
lines.push_str(">");
} else {
lines.push(ch);
}
}
let split = lines.split("\n");
let split_len = split.clone().collect::<Vec<&str>>().len();
let mut index = 0;
for val in split {
if val.len() > 1 {
html.push_str(&format!("<span class=\"hl-cmt\">{}</span>", val));
}
index = index + 1;
if index != split_len {
line = line + 1;
html.push_str("</td></tr>\n");
html.push_str(&format!(
"<tr><td class=\"hl-num\" data-line=\"{}\"></td><td>",
line
));
}
}
}
Token::ENDL(_) => {
line = line + 1;
html.push_str("</td></tr>\n");
html.push_str(&format!(
"<tr><td class=\"hl-num\" data-line=\"{}\"></td><td>",
line
));
}
_ => {
html.push(l.ch);
l.read_char();
}
}
}
html.push_str("</tbody>\n");
html.push_str("</table>");
html
}