| 1 | use core::slice::Iter;
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| 2 | use std::iter::Peekable;
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| 3 |
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| 4 | use anyhow::anyhow;
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| 5 |
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| 6 | use crate::tokenizer::Token;
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| 7 |
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| 8 | #[derive(Debug, Clone)]
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| 9 | pub enum ParserValue {
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| 10 | SimpleString(String),
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| 11 | BulkString(String),
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| 12 | Array(Vec<ParserValue>),
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| 13 | NullBulkString,
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| 14 | }
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| 15 |
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| 16 | impl ParserValue {
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| 17 | pub fn is_string(self: &ParserValue) -> bool {
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| 18 | matches!(self, ParserValue::SimpleString(_)) || matches!(self, ParserValue::BulkString(_))
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| 19 | }
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| 20 |
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| 21 | pub fn is_array(self: &ParserValue) -> bool {
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| 22 | matches!(self, ParserValue::Array(_))
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| 23 | }
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| 24 |
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| 25 | pub fn to_string(self: &ParserValue) -> Option<String> {
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| 26 | match self {
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| 27 | ParserValue::SimpleString(s) => Some(s.clone()),
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| 28 | ParserValue::BulkString(s) => Some(s.clone()),
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| 29 | _ => None,
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| 30 | }
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| 31 | }
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| 32 |
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| 33 | pub fn to_vec(self: &ParserValue) -> Option<&Vec<ParserValue>> {
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| 34 | match self {
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| 35 | ParserValue::Array(arr) => Some(arr),
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| 36 | _ => None,
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| 37 | }
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| 38 | }
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| 39 |
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| 40 | pub fn to_tokens(self: &ParserValue) -> Vec<Token> {
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| 41 | match self {
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| 42 | ParserValue::SimpleString(s) => {
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| 43 | vec![Token::Plus, Token::String(s.clone()), Token::Separator]
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| 44 | }
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| 45 | ParserValue::BulkString(s) => {
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| 46 | vec![
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| 47 | Token::Dollar,
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| 48 | Token::Number(s.len() as i64),
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| 49 | Token::Separator,
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| 50 | Token::String(s.clone()),
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| 51 | Token::Separator,
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| 52 | ]
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| 53 | }
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| 54 | ParserValue::Array(arr) => {
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| 55 | let mut tokens = vec![
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| 56 | Token::Asterisk,
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| 57 | Token::Number(arr.len() as i64),
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| 58 | Token::Separator,
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| 59 | ];
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| 60 | for parser_value in arr {
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| 61 | tokens.append(&mut parser_value.to_tokens());
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| 62 | }
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| 63 | tokens
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| 64 | }
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| 65 | ParserValue::NullBulkString => {
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| 66 | vec![Token::Dollar, Token::Number(-1), Token::Separator]
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| 67 | }
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| 68 | }
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| 69 | }
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| 70 | }
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| 71 |
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| 72 | pub fn parse_tokens(tokens: &[Token]) -> Option<ParserValue> {
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| 73 | if tokens.is_empty() {
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| 74 | return None;
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| 75 | }
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| 76 |
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| 77 | let mut tokens_iter = tokens.iter().peekable();
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| 78 | let first = tokens_iter.peek().expect("must have at least one token");
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| 79 |
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| 80 | eprintln!("First Token {:?}", first);
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| 81 |
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| 82 | match first {
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| 83 | // Simple String
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| 84 | Token::Plus => {
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| 85 | if let Ok(simple_string) = tokens_to_simple_string(&mut tokens_iter) {
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| 86 | return Some(simple_string);
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| 87 | }
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| 88 |
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| 89 | None
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| 90 | }
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| 91 | // Bulk String
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| 92 | Token::Dollar => {
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| 93 | if let Ok(bulk_string) = tokens_to_bulk_string(&mut tokens_iter) {
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| 94 | return Some(bulk_string);
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| 95 | }
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| 96 |
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| 97 | None
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| 98 | }
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| 99 | // Array
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| 100 | Token::Asterisk => match tokens_to_array(&mut tokens_iter) {
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| 101 | Ok(arr) => Some(arr),
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| 102 | Err(err) => {
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| 103 | eprintln!("{:?}", err);
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| 104 | None
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| 105 | }
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| 106 | },
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| 107 | _ => None,
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| 108 | }
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| 109 | }
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| 110 |
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| 111 | fn tokens_to_simple_string(token_iter: &mut Peekable<Iter<Token>>) -> anyhow::Result<ParserValue> {
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| 112 | if !token_iter.next().is_some_and(|t| t.is_plus()) {
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| 113 | return Err(anyhow!("first token in simple string must be a plus"));
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| 114 | }
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| 115 | let str_token = token_iter
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| 116 | .next()
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| 117 | .expect("should have a second token for simple string");
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| 118 |
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| 119 | let separator_token = token_iter
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| 120 | .next()
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| 121 | .expect("should have a third token for simple string");
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| 122 |
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| 123 | if !separator_token.is_separator() {
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| 124 | return Err(anyhow!("third token in simple string must be a separator"));
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| 125 | }
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| 126 |
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| 127 | Ok(ParserValue::SimpleString(str_token.to_string().expect(
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| 128 | "should be able to get strings from string tokens",
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| 129 | )))
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| 130 | }
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| 131 |
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| 132 | fn tokens_to_bulk_string(token_iter: &mut Peekable<Iter<Token>>) -> anyhow::Result<ParserValue> {
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| 133 | if !token_iter.next().is_some_and(|t| t.is_dollar()) {
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| 134 | return Err(anyhow!("first token in bulk string must be a dollar sign"));
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| 135 | }
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| 136 | let size_token = token_iter
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| 137 | .next()
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| 138 | .expect("should have second token for bulk string");
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| 139 | if !size_token.is_number() {
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| 140 | return Err(anyhow!("second token in bulk string must be a number"));
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| 141 | }
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| 142 | let separator_token = token_iter
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| 143 | .next()
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| 144 | .expect("should have a third token for simple string");
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| 145 | if !separator_token.is_separator() {
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| 146 | return Err(anyhow!("third token in bulk string must be a separator"));
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| 147 | }
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| 148 | let mut str_tokens = Vec::new();
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| 149 | while token_iter.peek().is_some_and(|t| !t.is_separator()) {
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| 150 | let str_token = token_iter.next().expect("should str_token");
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| 151 | str_tokens.push(str_token);
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| 152 | }
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| 153 |
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| 154 | let separator_token = token_iter
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| 155 | .next()
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| 156 | .expect("should have a fifth token for simple string");
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| 157 | if !separator_token.is_separator() {
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| 158 | return Err(anyhow!("fifth token in bulk string must be a separator"));
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| 159 | }
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| 160 | let mut s = String::with_capacity(size_token.to_usize().expect("size_token must be a usize"));
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| 161 | for t in str_tokens.iter() {
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| 162 | match t {
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| 163 | Token::Plus => {
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| 164 | s.push('+');
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| 165 | }
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| 166 | Token::Hyphen => {
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| 167 | s.push('-');
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| 168 | }
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| 169 | Token::Colon => {
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| 170 | s.push(':');
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| 171 | }
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| 172 | Token::Dollar => {
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| 173 | s.push('$');
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| 174 | }
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| 175 | Token::Asterisk => {
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| 176 | s.push('*');
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| 177 | }
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| 178 | Token::Underscore => {
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| 179 | s.push('_');
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| 180 | }
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| 181 | Token::PoundSign => {
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| 182 | s.push('#');
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| 183 | }
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| 184 | Token::Comma => {
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| 185 | s.push(',');
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| 186 | }
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| 187 | Token::LeftParenthesis => {
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| 188 | s.push('(');
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| 189 | }
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| 190 | Token::Exclamation => {
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| 191 | s.push('!');
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| 192 | }
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| 193 | Token::Equals => {
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| 194 | s.push('=');
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| 195 | }
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| 196 | Token::Percentage => {
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| 197 | s.push('%');
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| 198 | }
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| 199 | Token::Tilda => {
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| 200 | s.push('~');
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| 201 | }
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| 202 | Token::GreaterThan => {
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| 203 | s.push('>');
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| 204 | }
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| 205 | Token::String(ts) => s.push_str(ts),
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| 206 | Token::Number(n) => s.push_str(n.to_string().as_str()),
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| 207 | Token::Separator => {}
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| 208 | }
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| 209 | }
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| 210 | if s.len() != size_token.to_usize().expect("size_token must be a usize") {
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| 211 | return Err(anyhow!("incorrect string size in bulk token"));
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| 212 | }
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| 213 |
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| 214 | Ok(ParserValue::BulkString(s))
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| 215 | }
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| 216 |
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| 217 | fn tokens_to_array(token_iter: &mut Peekable<Iter<Token>>) -> anyhow::Result<ParserValue> {
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| 218 | if !token_iter.next().is_some_and(|t| t.is_asterisk()) {
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| 219 | return Err(anyhow!("first token in bulk string must be an asterisk"));
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| 220 | }
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| 221 | let length = token_iter.next().expect("should have a length token");
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| 222 | eprintln!("Length Token: {:?}", length);
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| 223 | if !length.is_number() {
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| 224 | return Err(anyhow!("second token in array should be length"));
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| 225 | }
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| 226 | let length = length.to_i64().expect("number token should have i64");
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| 227 | eprintln!("Length: {:?}", length);
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| 228 | if length < 0 {
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| 229 | return Err(anyhow!("array length cannot be negative"));
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| 230 | }
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| 231 |
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| 232 | if length == 0 {
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| 233 | return Ok(ParserValue::Array(Vec::new()));
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| 234 | }
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| 235 |
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| 236 | if !token_iter.next().is_some_and(|t| t.is_separator()) {
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| 237 | return Err(anyhow!("third token in an array must be a separator"));
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| 238 | }
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| 239 |
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| 240 | let mut values: Vec<ParserValue> = Vec::with_capacity(length as usize);
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| 241 | for _ in 0..length {
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| 242 | let first = token_iter.peek().expect("should have next token in array");
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| 243 | eprintln!("First Array Token: {:?}", first);
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| 244 | match first {
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| 245 | Token::Plus => {
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| 246 | let simple_string = tokens_to_simple_string(token_iter);
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| 247 | if let Ok(simple_string) = simple_string {
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| 248 | values.push(simple_string);
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| 249 | } else {
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| 250 | return Err(simple_string.err().unwrap());
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| 251 | }
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| 252 | }
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| 253 | Token::Dollar => {
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| 254 | let bulk_string = tokens_to_bulk_string(token_iter);
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| 255 | if let Ok(bulk_string) = bulk_string {
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| 256 | values.push(bulk_string);
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| 257 | } else {
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| 258 | let err = bulk_string.err().unwrap();
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| 259 | eprintln!("{:?}", err);
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| 260 | return Err(err);
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| 261 | }
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| 262 | }
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| 263 | Token::Asterisk => {
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| 264 | let arr = tokens_to_array(token_iter);
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| 265 | if let Ok(arr) = arr {
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| 266 | values.push(arr);
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| 267 | } else {
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| 268 | return Err(arr.err().unwrap());
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| 269 | }
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| 270 | }
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| 271 | _ => return Err(anyhow!("unexpected starting token in array")),
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| 272 | }
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| 273 | }
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| 274 |
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| 275 | Ok(ParserValue::Array(values))
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| 276 | }
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| 277 |
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| 278 | #[cfg(test)]
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| 279 | mod tests {
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| 280 | use super::*;
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| 281 |
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| 282 | #[test]
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| 283 | fn test_parses_bulk_string_with_negative_number() {
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| 284 | let tokens = [
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| 285 | Token::Dollar,
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| 286 | Token::Number(2),
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| 287 | Token::Separator,
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| 288 | Token::Hyphen,
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| 289 | Token::Number(1),
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| 290 | Token::Separator,
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| 291 | ];
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| 292 | let result = tokens_to_bulk_string(&mut tokens.iter().peekable());
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| 293 | assert!(result.is_ok());
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| 294 | assert_eq!(
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| 295 | ParserValue::BulkString("-1".to_string())
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| 296 | .to_string()
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| 297 | .unwrap(),
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| 298 | result.unwrap().to_string().unwrap()
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| 299 | );
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| 300 | }
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| 301 |
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| 302 | #[test]
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| 303 | fn test_parses_bulk_string() {
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| 304 | let tokens = [
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| 305 | Token::Dollar,
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| 306 | Token::Number(5),
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| 307 | Token::Separator,
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| 308 | Token::String("PSYNC".to_string()),
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| 309 | Token::Separator,
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| 310 | ];
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| 311 |
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| 312 | let result = tokens_to_bulk_string(&mut tokens.iter().peekable());
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| 313 | assert!(result.is_ok());
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| 314 | assert_eq!(
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| 315 | ParserValue::BulkString("PSYNC".to_string())
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| 316 | .to_string()
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| 317 | .unwrap(),
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| 318 | result.unwrap().to_string().unwrap()
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| 319 | );
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| 320 | }
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| 321 | }
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| 322 |
|