feat(tokenizer): string tokenizing

notes.org

@@ -212,7 +212,24 @@ i will use rustyline, since it seems like the most feature-complete
 
 * DONE remove uneeded error variants
 
-* TODO cli tests using insta-cmd
+* DONE parse integers
+
+** DONE Function to get a token until condition is false
+
+** DONE Parse the integer
+
+* DONE parse strings
+
+* TODO better error message display for unclosed " in string
+
+* TODO parse insert statements in the form
+insert <id:int> <username:string> <email:string>
+** TODO Row struct
+** TODO parse row insert
+** TODO serialize/deserialize row to/from raw bytes
+*** TODO look for best practices for creating binary formats
+
+* WAIT cli tests using insta-cmd
 https://insta.rs/docs/cmd/
 
 * WAIT autocompletion

src/cli.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use rustyline::{history::FileHistory, Editor};
+use rustyline::{Editor, history::FileHistory};
 
 fn xdg_state_dir() -> Option<PathBuf> {
     if let Ok(dir) = std::env::var("XDG_STATE_DIR") {
@@ -31,7 +31,9 @@ pub fn history_file() -> Option<std::path::PathBuf> {
         Some(state.join("cli_history"))
     } else {
         eprintln!("Warning: failed to find or create XDG_STATE_DIR for osdb.");
-        eprintln!("Warning: either set XDG_STATE_DIR or HOME, and ensure osdb has write permissions to that directory.");
+        eprintln!(
+            "Warning: either set XDG_STATE_DIR or HOME, and ensure osdb has write permissions to that directory."
+        );
         None
     }
 }

src/command.rs

@@ -1,6 +1,6 @@
 use crate::meta_commands::{MetaCommand, MetaCommandExecuteResult};
 use crate::statements::{Statement, StatementExecuteResult};
-use crate::tokens::ScanError;
+use crate::tokens::{ScanError, Token};
 
 #[derive(Debug)]
 pub enum Command {
@@ -50,6 +50,7 @@ impl Command {
 #[derive(Debug)]
 pub enum CommandParseError {
     Scan(ScanError),
+    UnexpectedToken(Token, &'static [&'static str]),
 }
 
 impl From<MetaCommand> for Command {

src/error_display.rs

@@ -7,9 +7,26 @@ pub trait OSDBError {
 
 impl OSDBError for CommandParseError {
     fn display(&self, file: &str, input: &str) {
-        let CommandParseError::Scan(x) = self;
+        match self {
+            CommandParseError::Scan(x) => {
                 x.display(file, input);
             }
+            CommandParseError::UnexpectedToken(token, items) => {
+                let location = (file, Into::<std::ops::Range<usize>>::into(&token.location));
+                Report::build(ReportKind::Error, location.clone())
+                    .with_message("unexpected token")
+                    .with_label(
+                        Label::new(location.clone())
+                            .with_color(Color::Red)
+                            .with_message(format!("found {token}")),
+                    )
+                    .with_note(format!("expected token type to be one of {items:?}"))
+                    .finish()
+                    .print((file, Source::from(input)))
+                    .unwrap()
+            }
+        }
+    }
 }
 
 impl OSDBError for ScanError {
@@ -22,7 +39,6 @@ impl OSDBError for ScanError {
                     .with_color(Color::Red)
                     .with_message(format!("{self}")),
             )
-            .with_help("Make sure you don't have any typos or unexpected characters.")
             .finish()
             .print((file, Source::from(input)))
             .unwrap();

src/meta_commands.rs

@@ -3,6 +3,14 @@ pub enum MetaCommand {
     Exit,
 }
 
+impl std::fmt::Display for MetaCommand {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            MetaCommand::Exit => write!(f, "exit"),
+        }
+    }
+}
+
 pub struct MetaCommandExecuteResult {
     pub should_exit: bool,
 }

src/parser.rs

@@ -11,7 +11,7 @@ pub fn parse(file: String, input: String) -> Result<Vec<Command>, Vec<CommandPar
         .map_err(|x| x.into_iter().map(|x| x.into()).collect::<Vec<_>>())?
         .into();
     let mut cmds = Vec::new();
-    let errs = Vec::new();
+    let mut errs = Vec::new();
     while let Some(token) = tokens.pop_front() {
         match token.data {
             crate::tokens::TokenData::Insert => cmds.push(Command::Statement(Statement::Insert)),
@@ -19,6 +19,14 @@ pub fn parse(file: String, input: String) -> Result<Vec<Command>, Vec<CommandPar
             crate::tokens::TokenData::MetaCommand(meta_command) => {
                 cmds.push(Command::MetaCommand(meta_command))
             }
+            crate::tokens::TokenData::Int(_) => errs.push(CommandParseError::UnexpectedToken(
+                token,
+                &["statement", "meta command", "eof"],
+            )),
+            crate::tokens::TokenData::String(_) => errs.push(CommandParseError::UnexpectedToken(
+                token,
+                &["statement", "meta command", "eof"],
+            )),
             crate::tokens::TokenData::EndOfFile => (),
         }
     }

src/snapshots/osdb__tokens__tests__tokenizer_errors.snap

@@ -1,8 +1,9 @@
 ---
 source: src/tokens.rs
-expression: scanerrors
+expression: "tokenize(\"salact +\".to_string(), \"src/statement.sql\".to_string())"
 ---
-[
+Err(
+    [
         ScanError {
             location: Location {
                 file: "src/statement.sql",
@@ -19,8 +20,11 @@ expression: scanerrors
                 offset: 7,
                 length: 1,
             },
-        kind: UnexpectedChar(
-            '+',
+            kind: ParseIntError(
+                ParseIntError {
+                    kind: InvalidDigit,
+                },
             ),
         },
-]
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-2.snap

@@ -0,0 +1,28 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"-10\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Ok(
+    [
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 3,
+            },
+            data: Int(
+                -10,
+            ),
+            lexeme: "-10",
+        },
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 3,
+                length: 0,
+            },
+            data: EndOfFile,
+            lexeme: "",
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-3.snap

@@ -0,0 +1,28 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"0\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Ok(
+    [
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 1,
+            },
+            data: Int(
+                0,
+            ),
+            lexeme: "0",
+        },
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 1,
+                length: 0,
+            },
+            data: EndOfFile,
+            lexeme: "",
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-4.snap

@@ -0,0 +1,28 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"-0\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Ok(
+    [
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 2,
+            },
+            data: Int(
+                0,
+            ),
+            lexeme: "-0",
+        },
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 2,
+                length: 0,
+            },
+            data: EndOfFile,
+            lexeme: "",
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-5.snap

@@ -0,0 +1,20 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"--0\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Err(
+    [
+        ScanError {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 3,
+            },
+            kind: ParseIntError(
+                ParseIntError {
+                    kind: InvalidDigit,
+                },
+            ),
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-6.snap

@@ -0,0 +1,20 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"++0\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Err(
+    [
+        ScanError {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 3,
+            },
+            kind: ParseIntError(
+                ParseIntError {
+                    kind: InvalidDigit,
+                },
+            ),
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-7.snap

@@ -0,0 +1,20 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"-\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Err(
+    [
+        ScanError {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 1,
+            },
+            kind: ParseIntError(
+                ParseIntError {
+                    kind: InvalidDigit,
+                },
+            ),
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers-8.snap

@@ -0,0 +1,20 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"+\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Err(
+    [
+        ScanError {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 1,
+            },
+            kind: ParseIntError(
+                ParseIntError {
+                    kind: InvalidDigit,
+                },
+            ),
+        },
+    ],
+)

src/snapshots/osdb__tokens__tests__tokenizer_integers.snap

@@ -0,0 +1,28 @@
+---
+source: src/tokens.rs
+expression: "tokenize(\"10\".to_string(), \"src/ints.sql\".to_string(),)"
+---
+Ok(
+    [
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 0,
+                length: 2,
+            },
+            data: Int(
+                10,
+            ),
+            lexeme: "10",
+        },
+        Token {
+            location: Location {
+                file: "src/ints.sql",
+                offset: 2,
+                length: 0,
+            },
+            data: EndOfFile,
+            lexeme: "",
+        },
+    ],
+)

src/tokens.rs

@@ -6,6 +6,8 @@ pub enum TokenData {
     Select,
     MetaCommand(MetaCommand),
     EndOfFile,
+    Int(i64),
+    String(String),
 }
 
 #[derive(Debug, Eq, PartialEq)]
@@ -54,6 +56,21 @@ pub struct Token {
     pub lexeme: String,
 }
 
+impl std::fmt::Display for Token {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match &self.data {
+            TokenData::Insert => write!(f, "insert statement"),
+            TokenData::Select => write!(f, "select statement"),
+            TokenData::MetaCommand(x) => write!(f, "meta-command {x}"),
+            TokenData::EndOfFile => write!(f, "end of file"),
+            TokenData::Int(x) => write!(f, "integer {x}"),
+            TokenData::String(x) => write!(f, "string {x:?}"),
+        }?;
+        let lexeme = &self.lexeme;
+        write!(f, " {lexeme:?}")
+    }
+}
+
 struct Tokenizer {
     input: String,
     file: String,
@@ -67,6 +84,8 @@ pub enum ScanErrorKind {
     UnexpectedEndOfInput,
     UnknownKeyword(String),
     UnknownMetaCommand(String),
+    ParseIntError(std::num::ParseIntError),
+    UnexpectedEndOfInputWhileLookingForMatching(char, Location),
 }
 
 impl std::fmt::Display for ScanErrorKind {
@@ -76,6 +95,11 @@ impl std::fmt::Display for ScanErrorKind {
             ScanErrorKind::UnexpectedEndOfInput => write!(f, "unexpected end of input"),
             ScanErrorKind::UnknownKeyword(x) => write!(f, "unknown keyword: {x:?}"),
             ScanErrorKind::UnknownMetaCommand(x) => write!(f, "unknown meta-command: {x:?}"),
+            ScanErrorKind::ParseIntError(x) => write!(f, "failed to parse integer: {x}"),
+            ScanErrorKind::UnexpectedEndOfInputWhileLookingForMatching(c, _) => write!(
+                f,
+                "unexpected end of input while looking for matching {c:?}"
+            ),
         }
     }
 }
@@ -107,6 +131,10 @@ impl Tokenizer {
         Location::new(self.file.clone(), self.offset, length)
     }
 
+    fn previous_location(&self, length: usize) -> Location {
+        Location::new(self.file.clone(), self.offset - 1, length)
+    }
+
     fn is_at_end(&self) -> bool {
         self.offset >= self.input.len()
     }
@@ -206,6 +234,77 @@ impl Tokenizer {
         c.is_alphanumeric() || c == '_'
     }
 
+    fn digit(c: char) -> bool {
+        c.is_ascii_digit() || c == '-' || c == '+'
+    }
+
+    fn scan_integer(&mut self) -> Result<Token, ScanError> {
+        let start_offset = self.offset;
+        let mut word = String::new();
+        let mut length = 0;
+        if let Some(c) = self.advance() {
+            word.push(c);
+            length += 1;
+        }
+        while let Some(c) = self.peek() {
+            if Self::digit(c) {
+                word.push(c);
+                self.advance();
+            } else {
+                break;
+            }
+            length += 1;
+        }
+        match word.parse::<i64>() {
+            Ok(int) => Ok(Token {
+                location: Location::new(self.file.clone(), start_offset, length),
+                data: TokenData::Int(int),
+                lexeme: word,
+            }),
+            Err(e) => Err(ScanError {
+                location: Location::new(self.file.clone(), start_offset, length),
+                kind: ScanErrorKind::ParseIntError(e),
+            }),
+        }
+    }
+
+    fn scan_string(&mut self) -> Result<Token, ScanError> {
+        let start_offset = self.offset;
+        let mut word = String::new();
+        let mut lexeme = String::new();
+        let mut length = 0;
+        let mut valid = false;
+        if let Some(c) = self.advance() {
+            lexeme.push(c);
+            length += 1;
+        }
+        while let Some(c) = self.advance() {
+            lexeme.push(c);
+            length += 1;
+            if c == '"' {
+                valid = true;
+                break;
+            } else {
+                word.push(c);
+            }
+        }
+        if valid {
+            Ok(Token {
+                location: Location::new(self.file.clone(), start_offset, length),
+                data: TokenData::String(word),
+                lexeme,
+            })
+        } else {
+            Err(ScanError {
+                location: self.previous_location(0),
+                kind: ScanErrorKind::UnexpectedEndOfInputWhileLookingForMatching(
+                    '"',
+                    Location::new(self.file.clone(), start_offset, 1),
+                ),
+            })
+        }
+    }
+
     fn scan_token(&mut self) -> Result<Option<Token>, ScanError> {
         loop {
             if let Some(c) = self.peek() {
@@ -213,6 +312,10 @@ impl Tokenizer {
                     return self.scan_identifier_or_keyword().map(Some);
                 } else if c == '.' {
                     return self.scan_meta_command().map(Some);
+                } else if Self::digit(c) {
+                    return self.scan_integer().map(Some);
+                } else if c == '"' {
+                    return self.scan_string().map(Some);
                 } else if c.is_whitespace() {
                     self.advance();
                 } else {
@@ -307,9 +410,21 @@ mod tests {
 
     #[test]
     fn test_tokenizer_errors() {
-        let scanerrors = tokenize("salact +".to_string(), "src/statement.sql".to_string())
-            .err()
-            .unwrap();
-        assert_debug_snapshot!(scanerrors);
+        assert_debug_snapshot!(tokenize(
+            "salact +".to_string(),
+            "src/statement.sql".to_string()
+        ));
+    }
+
+    #[test]
+    fn test_tokenizer_integers() {
+        assert_debug_snapshot!(tokenize("10".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("-10".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("0".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("-0".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("--0".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("++0".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("-".to_string(), "src/ints.sql".to_string(),));
+        assert_debug_snapshot!(tokenize("+".to_string(), "src/ints.sql".to_string(),));
     }
 }