command_parser: switch from logos to nom

firmware/Cargo.lock

@@ -169,8 +169,8 @@ dependencies = [
  "crc 1.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "embedded-hal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libm 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "logos 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "nb 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nom 5.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "smoltcp 0.4.0 (git+https://github.com/m-labs/smoltcp?rev=cd893e6)",
  "tm4c129x 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "walkdir 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -195,36 +195,30 @@ name = "linked_list_allocator"
 version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "logos"
-version = "0.9.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "logos-derive 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "logos-derive"
-version = "0.9.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
- "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.44 (registry+https://github.com/rust-lang/crates.io-index)",
- "utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "managed"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "memchr"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "nb"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "nom"
+version = "5.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.8"
@@ -275,11 +269,6 @@ name = "rand_core"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "regex-syntax"
-version = "0.6.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -357,13 +346,13 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "utf8-ranges"
+name = "vcell"
-version = "1.0.4"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "vcell"
+name = "version_check"
-version = "0.1.2"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -428,10 +417,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum libm 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7fc7aa29613bd6a620df431842069224d8bc9011086b1db4c0e0cd47fa03ec9a"
 "checksum linked_list_allocator 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "47314ec1d29aa869ee7cb5a5be57be9b1055c56567d59c3fb6689926743e0bea"
-"checksum logos 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f494e22d293fa05db60b3fd95fb30e9409feb5672b56ce6f250f99d9fbae6b93"
-"checksum logos-derive 0.9.7 (registry+https://github.com/rust-lang/crates.io-index)" = "13ff1b1068db09ee21d12baf55eccc0900a781a735273e0a606f6f4fbb32a322"
 "checksum managed 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "43e2737ecabe4ae36a68061398bf27d2bfd0763f4c3c837a398478459494c4b7"
+"checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
 "checksum nb 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b1411551beb3c11dedfb0a90a0fa256b47d28b9ec2cdff34c25a2fa59e45dbdc"
+"checksum nom 5.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c618b63422da4401283884e6668d39f819a106ef51f5f59b81add00075da35ca"
 "checksum num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
 "checksum proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)" = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
 "checksum quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
@@ -439,7 +428,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rand 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c618c47cd3ebd209790115ab837de41425723956ad3ce2e6a7f09890947cacb9"
 "checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
 "checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
-"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum same-file 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d931a44fdaa43b8637009e7632a02adc4f2b2e0733c08caa4cf00e8da4a117a7"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
@@ -450,8 +438,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum tm4c129x 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7d430ed4ed06dd9fff3d4517a37343e1b53789218f2f608bf1e0432f67abf624"
 "checksum typenum 1.11.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6d2783fe2d6b8c1101136184eb41be8b1ad379e4657050b8aaff0c79ee7575f9"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
-"checksum utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b4ae116fef2b7fea257ed6440d3cfcff7f190865f170cdad00bb6465bf18ecba"
 "checksum vcell 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "876e32dcadfe563a4289e994f7cb391197f362b6315dc45e8ba4aa6f564a4b3c"
+"checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum volatile-register 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a470889aa8f2d3ad893bd43cd90c824e63e8ac0ee5fe64c5d81a932d184fd549"
 "checksum volatile-register 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0d67cb4616d99b940db1d6bd28844ff97108b498a6ca850e5b6191a532063286"

firmware/Cargo.toml

@@ -19,9 +19,11 @@ cortex-m-semihosting = "0.3"
 byteorder = { version = "1.3", default-features = false }
 bit_field = "0.10"
 bare-metal = "0.2"
-logos = { version = "~0.9", default-features = false, features = ["export_derive"] }
+# TODO: remove
 alloc-cortex-m = "0.3"
+# TODO: needed with nom?
 btoi = { version = "~0.4", default-features = false }
+nom = { version = "~5", default-features = false }
 
 [dependencies.smoltcp]
 git = "https://github.com/m-labs/smoltcp"

firmware/src/command_parser.rs

@@ -1,125 +1,133 @@
-use logos::Logos;
+use nom::{
+    IResult,
+    branch::alt,
+    bytes::complete::{tag, take_while1},
+    character::{is_digit, complete::char},
+    combinator::{map, value},
+    sequence::{preceded, tuple, Tuple},
+    multi::fold_many1,
+    error::ErrorKind,
+};
 use btoi::{btoi, ParseIntegerError};
 use super::session::ReportMode;
 
-#[derive(Logos, Debug, PartialEq)]
-enum Token {
-    #[end]
-    End,
-    #[error]
-    Error,
-
-    #[token = "Quit"]
-    Quit,
-    #[token = "report"]
-    Report,
-    #[token = "mode"]
-    Mode,
-    #[token = "off"]
-    Off,
-    #[token = "once"]
-    Once,
-    #[token = "continuous"]
-    Continuous,
-    #[token = "pwm"]
-    Pwm,
-
-    #[regex = "[0-9]+"]
-    Number,
-}
 
 #[derive(Debug)]
 pub enum Error {
-    Parser,
+    Parser(ErrorKind),
-    UnexpectedEnd,
+    Incomplete,
-    UnexpectedToken(Token),
+    UnexpectedInput(u8),
     ParseInteger(ParseIntegerError)
 }
 
+impl<'t> From<nom::Err<(&'t [u8], ErrorKind)>> for Error {
+    fn from(e: nom::Err<(&'t [u8], ErrorKind)>) -> Self {
+        match e {
+            nom::Err::Incomplete(_) =>
+                Error::Incomplete,
+            nom::Err::Error((_, e)) =>
+                Error::Parser(e),
+            nom::Err::Failure((_, e)) =>
+                Error::Parser(e),
+        }
+    }
+}
+
 impl From<ParseIntegerError> for Error {
     fn from(e: ParseIntegerError) -> Self {
         Error::ParseInteger(e)
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum ShowCommand {
     ReportMode,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Command {
     Quit,
     Show(ShowCommand),
     Report(ReportMode),
     Pwm {
-        pwm_match: u32,
+        width: u32,
-        pwm_reload: u32,
+        total: u32,
     },
 }
 
+fn whitespace(input: &[u8]) -> IResult<&[u8], ()> {
+    fold_many1(char(' '), (), |(), _| ())(input)
+}
+
+fn unsigned(input: &[u8]) -> IResult<&[u8], Result<u32, ParseIntegerError>> {
+    take_while1(is_digit)(input)
+        .map(|(input, digits)| (input, btoi(digits)))
+}
+
+fn report_mode(input: &[u8]) -> IResult<&[u8], ReportMode> {
+    alt((value(ReportMode::Off, tag("off")),
+         value(ReportMode::Once, tag("once")),
+         value(ReportMode::Continuous, tag("continuous"))
+    ))(input)
+}
+
+fn report(input: &[u8]) -> IResult<&[u8], Command> {
+    preceded(
+        preceded(
+            tag("report"),
+            whitespace
+        ),
+        alt((
+            preceded(
+                whitespace,
+                preceded(
+                    tag("mode"),
+                    alt((
+                        preceded(
+                            whitespace,
+                            map(report_mode,
+                                |mode| Command::Report(mode))
+                        ),
+                        |input| Ok((input, Command::Show(ShowCommand::ReportMode)))
+                    ))
+                )),
+            |input| Ok((input, Command::Report(ReportMode::Once)))
+        ))
+    )(input)
+}
+
+fn pwm(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
+    let (input, _) = tag("pwm")(input)?;
+    let (input, _) = whitespace(input)?;
+    let (input, width) = unsigned(input)?;
+    let width = match width {
+        Ok(width) => width,
+        Err(e) => return Ok((input, Err(e.into()))),
+    };
+    let (input, _) = whitespace(input)?;
+    let (input, total) = unsigned(input)?;
+    let total = match total {
+        Ok(total) => total,
+        Err(e) => return Ok((input, Err(e.into()))),
+    };
+    Ok((input, Ok(Command::Pwm { width, total })))
+}
+
+fn command(input: &[u8]) -> IResult<&[u8], Command> {
+    alt((value(Command::Quit, tag("quit")),
+         report
+    ))(input)
+}
+
 impl Command {
-    pub fn parse(input: &str) -> Result<Self, Error> {
+    pub fn parse(input: &[u8]) -> Result<Self, Error> {
-        let mut lexer = Token::lexer(input);
+        match command(input) {
-
+            Ok((b"", command)) =>
-        /// Match against a set of expected tokens
+                Ok(command),
-        macro_rules! choice {
+            Ok((input_remain, _)) =>
-            [$($token: tt => $block: stmt,)*] => {
+                Err(Error::UnexpectedInput(input_remain[0])),
-                match lexer.token {
+            Err(e) =>
-                    $(
+                Err(e.into()),
-                        Token::$token => {
+        }
-                            lexer.advance();
-                            $block
-                        }
-                    )*
-                    Token::End => return Err(Error::UnexpectedEnd),
-                    _ => return Err(Error::UnexpectedToken(lexer.token))
-                }
-            };
-        }
-        /// Expecting no further tokens
-        macro_rules! end {
-            ($result: expr) => {
-                match lexer.token {
-                    Token::End => Ok($result),
-                    _ => return Err(Error::UnexpectedToken(lexer.token)),
-                }
-            };
-        }
-
-        // Command grammar
-        choice![
-            Quit => Ok(Command::Quit),
-            Report => choice![
-                Mode => choice![
-                    End => end!(Command::Show(ShowCommand::ReportMode)),
-                    Off => Ok(Command::Report(ReportMode::Off)),
-                    Once => Ok(Command::Report(ReportMode::Once)),
-                    Continuous => Ok(Command::Report(ReportMode::Continuous)),
-                ],
-                End => Ok(Command::Report(ReportMode::Once)),
-            ],
-            Pwm => {
-                if lexer.token != Token::Number {
-                    return Err(Error::UnexpectedToken(lexer.token));
-                }
-                let pwm_match = btoi(lexer.slice().as_bytes())?;
-                lexer.advance();
-
-                if lexer.token != Token::Number {
-                    return Err(Error::UnexpectedToken(lexer.token));
-                }
-                let pwm_reload = btoi(lexer.slice().as_bytes())?;
-                lexer.advance();
-
-                if lexer.token != Token::End {
-                    return Err(Error::UnexpectedToken(lexer.token));
-                }
-
-                end!(Command::Pwm {
-                    pwm_match, pwm_reload,
-                })
-            },
-        ]
     }
 }

firmware/src/main.rs

@@ -265,9 +265,9 @@ fn main() -> ! {
                         Command::Show(ShowCommand::ReportMode) => {
                             let _ = writeln!(socket, "Report mode: {:?}", session.report_mode());
                         }
-                        Command::Pwm { pwm_match, pwm_reload } => {
+                        Command::Pwm { width, total } => {
-                            board::set_timer_pwm(pwm_match, pwm_reload);
+                            board::set_timer_pwm(width, total);
-                            let _ = writeln!(socket, "PWM duty cycle: {}/{}", pwm_match, pwm_reload);
+                            let _ = writeln!(socket, "PWM duty cycle: {}/{}", width, total);
                         }
                     }
                     Ok(SessionOutput::Error(e)) => {

firmware/src/session.rs

@@ -1,6 +1,6 @@
+use core::ops::Deref;
 use super::command_parser::{Command, Error as ParserError};
 
-
 const MAX_LINE_LEN: usize = 64;
 
 struct LineReader {
@@ -16,13 +16,16 @@ impl LineReader {
         }
     }
 
-    pub fn feed(&mut self, c: u8) -> Option<&str> {
+    pub fn feed(&mut self, c: u8) -> Option<LineResult> {
         if c == 13 || c == 10 {
             // Enter
             if self.pos > 0 {
                 let len = self.pos;
                 self.pos = 0;
-                core::str::from_utf8(&self.buf[..len]).ok()
+                Some(LineResult {
+                    buf: self.buf.clone(),
+                    len,
+                })
             } else {
                 None
             }
@@ -38,6 +41,18 @@ impl LineReader {
     }
 }
 
+pub struct LineResult {
+    buf: [u8; MAX_LINE_LEN],
+    len: usize,
+}
+
+impl Deref for LineResult {
+    type Target = [u8];
+    fn deref(&self) -> &Self::Target {
+        &self.buf[..self.len]
+    }
+}
+
 #[derive(Debug, Clone, Copy)]
 pub enum ReportMode {
     Off,
@@ -105,9 +120,10 @@ impl Session {
         let mut buf_bytes = 0;
         for (i, b) in buf.iter().enumerate() {
             buf_bytes = i + 1;
-            match self.reader.feed(*b) {
+            let line = self.reader.feed(*b);
+            match line {
                 Some(line) => {
-                    let command = Command::parse(line);
+                    let command = Command::parse(&line);
                     match command {
                         Ok(Command::Report(mode)) => {
                             self.report_mode = mode;