Cargo.toml

@@ -9,4 +9,5 @@ edition = "2021"
 num = "0.4"
 clap = { version = "3.1.8", features = ["derive"] }
 chrono = "0.4"
-function_name = "0.3.0"
+function_name = "0.3.0"
+itertools = "0.10.3"

src/main.rs

@@ -14,7 +14,7 @@ fn main() -> std::io::Result<()> {
     let args = Cli::parse();
 
     let file           = File::open(&args.path)?;
-    dbg!(["hello", "goodbye", "myworld"].contains(&"myworlde"));
+    // dbg!(["hello", "goodbye", "myworld"].contains(&"myworlde"));
     // let mut word_gen   = WordReader::new(file);
     // let mut word_count = 0;
 
@@ -26,8 +26,8 @@ fn main() -> std::io::Result<()> {
     // let word1 = "hello world";
     // let word2 = "hello planet";
     // dbg!(&word1[0..6].len());
-    dbg!(take_until("tea time  now: and later", b':'));
-    // parse_vcd(file);
+    // dbg!(take_until("tea time  now: and later", b':'));
+    parse_vcd(file);
 
     // tag("my oh my");
 

src/vcd/parse.rs

@@ -1,4 +1,6 @@
 use super::*;
+use chrono::prelude::*;
+use itertools::Itertools;
 use std::fs::File;
 use ::function_name::named;
 
@@ -10,7 +12,7 @@ pub fn take_until<'a>(word : &'a str, pattern : u8) -> Option<(&'a str, Residual
 
     for chr in word.as_bytes() {
         if (*chr == pattern) {
-            return Some((&word[0..new_start], Residual(&word[new_start..])));
+            return Some((&word[0..new_start], Residual(&word[new_start+1..])));
         } 
         else {
             new_start += 1;
@@ -37,21 +39,17 @@ fn tag<'a>(word : &'a str, pattern : &'a str) -> Option<&'a str> {
 }
 
 #[named]
-fn parse_date(word_reader : &mut WordReader) -> Result<(), String> {
-    let mut parsed_day   = false;
-    let mut parsed_month = false;
-    let mut parsed_date  = false;
-    let mut parsed_hh    = false;
-    let mut parsed_mm    = false;
-    let mut parsed_ss    = false;
-    let mut parsed_year  = false;
-    let mut parsed_end   = false;
+fn parse_date(
+    word_and_ctx1 : (&str, Cursor),
+    word_and_ctx2 : (&str, Cursor),
+    word_and_ctx3 : (&str, Cursor),
+    word_and_ctx4 : (&str, Cursor),
+    word_and_ctx5 : (&str, Cursor),
+) -> Result<DateTime<Utc>, String> {
 
     let day = {
         // check for another word in the file
-        let (word, cursor) = word_reader.next_word().expect(
-            format!("reached end of file without parser leaving {}", function_name!()).as_str()
-        );
+        let (word, cursor) = word_and_ctx1;
     
         let days = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
         if !days.contains(&word) {
@@ -66,9 +64,7 @@ fn parse_date(word_reader : &mut WordReader) -> Result<(), String> {
 
     let month = {
         // check for another word in the file
-        let (word, cursor) = word_reader.next_word().expect(
-            format!("reached end of file without parser leaving {}", function_name!()).as_str()
-        );
+        let (word, cursor) = word_and_ctx2;
 
         let months = [
             "Jan", "Feb", "Mar", "Apr", 
@@ -88,9 +84,7 @@ fn parse_date(word_reader : &mut WordReader) -> Result<(), String> {
 
     let date = {
         // check for another word in the file
-        let (word, cursor) = word_reader.next_word().expect(
-            format!("reached end of file without parser leaving {}", function_name!()).as_str()
-        );
+        let (word, cursor) = word_and_ctx3;
 
         let date : u8 = word.to_string().parse().unwrap();
 
@@ -106,48 +100,63 @@ fn parse_date(word_reader : &mut WordReader) -> Result<(), String> {
     };
 
     let (hh, mm, ss) = {
-        // check for another word in the file
-        let (word, cursor) = word_reader.next_word().expect(
-            format!("reached end of file without parser leaving {}", function_name!()).as_str()
-        );
+        // get hour
+        let (word, cursor) = word_and_ctx4;
 
-        let date : u8 = word.to_string().parse().unwrap();
-        // let hh = take_until(word, b':').unwrap();
+        let (hh, Residual(remainder)) = take_until(word, b':').unwrap();
+        let hh : u8 = hh.to_string().parse().unwrap();
 
-        if date > 31 {
+        if hh > 23 {
             let msg  = format!("reached end of file without parser leaving {}\n", function_name!());
-            let msg2 = format!("{word} is not a valid date : must be between 0 and 31\n");
+            let msg2 = format!("{hh} is not a valid hour : must be between 0 and 23\n");
             let msg3 = format!("failure location: {cursor:?}");
             return Err(format!("{}{}{}", msg, msg2, msg3))
-
         }
-        ("", "", "")
+
+        // get minute
+        let (mm, Residual(remainder)) = take_until(remainder, b':').unwrap();
+        let mm : u8 = mm.to_string().parse().unwrap();
+
+        if mm > 60 {
+            let msg  = format!("reached end of file without parser leaving {}\n", function_name!());
+            let msg2 = format!("{mm} is not a valid minute : must be between 0 and 60\n");
+            let msg3 = format!("failure location: {cursor:?}");
+            return Err(format!("{}{}{}", msg, msg2, msg3))
+        }
+
+        // get second
+        let ss : u8 = remainder.to_string().parse().unwrap();
+
+        if ss > 60 {
+            let msg  = format!("reached end of file without parser leaving {}\n", function_name!());
+            let msg2 = format!("{ss} is not a valid second : must be between 0 and 60\n");
+            let msg3 = format!("failure location: {cursor:?}");
+            return Err(format!("{}{}{}", msg, msg2, msg3))
+        }
+        (hh.to_string(), mm.to_string(), ss.to_string())
     };
 
-    // else if !parsed_date {
+    let year = {
+        // check for another word in the file
+        let (word, cursor) = word_and_ctx5;
+        word.to_string()
+    };
 
-    // }
-    // else if !parsed_hh {
+    let date = Utc.datetime_from_str(
+        format!("{day} {month} {date} {mm}:{hh}:{ss} {year}").as_str(),
+        "%a %b %e %T %Y").unwrap();
 
-    // }
-    // else if !parsed_mm {
-
-    // }
-    // else if !parsed_ss {
-
-    // }
-    // else if !parsed_year {
-
-    // }
-    // else if !parsed_end {
-
-    // }
-
-    Ok(())
+    Ok(date)
 }
 
 #[named]
-fn parse_header(word_reader : &mut WordReader) -> Result<(), String> {
+fn parse_header(word_reader : &mut WordReader) -> Result<Metadata, String> {
+    let mut header = Metadata {
+        date : None,
+        version : None,
+        timescale : (None, Timescale::unit)
+    };
+
     loop {
         // check for another word in the file
         let word = word_reader.next_word();
@@ -165,10 +174,47 @@ fn parse_header(word_reader : &mut WordReader) -> Result<(), String> {
             // we hope that this word stars with a `$`
             Some(ident) =>  {
                 match ident {
-                    "date"      => {println!("got date")}
+                    "date"      => {
+                        let err_msg = format!("reached end of file without parser leaving {}", function_name!());
+                        // a date is typically composed of the 5 following words which can 
+                        // occur in any order: 
+                        // {Day, Month, Date(number in month), hh:mm:ss, year}.
+                        // Thus, we must lookahead read the 5 next words, and try our date
+                        // parser on 5! = 120 permutations of the 5 words.
+                        //
+                        // While looking ahead, if one of the 5 words in `$end`, we have to 
+                        // immediately stop trying to get more words.
+
+                        let mut found_end = false;
+                        let mut lookahead_5_words : Vec<(String, Cursor)> = Vec::new();
+
+                        for word in 0..5 {
+                            let (word, cursor) = word_reader.next_word().expect(err_msg.as_str());
+                            let word = word.to_string();
+                            match word.as_str() {
+                                "$end" => {
+                                    found_end = true;
+                                    break;
+                                }
+                                _ => {
+                                    lookahead_5_words.push((word, cursor));
+                                }
+                            };
+                        }
+
+                        // we no longer attempt to parse date if we weren't able to lookahead 5
+                        // words
+                        if found_end {continue}
+
+                        let iter =  lookahead_5_words
+                                    .iter()
+                                    .permutations(lookahead_5_words.len());
+                        // let parsed_date = parse_date(word_reader).unwrap();
+                        // header.date     = Some(parsed_date);
+                    }
                     "version"   => {println!("got version")}
                     "timescale" => {println!("got timescale")}
-                    "scope"     => {return Ok(())}
+                    "scope"     => {break}
                     _ => {}
                 }
             }
@@ -176,13 +222,13 @@ fn parse_header(word_reader : &mut WordReader) -> Result<(), String> {
             None => {}
         }
 
-
     }
-    // Ok()
+    return Ok(header)
 }
 
 pub fn parse_vcd(file : File) {
     let mut word_gen = WordReader::new(file);
 
-    parse_header(&mut word_gen);
+    let header = parse_header(&mut word_gen).unwrap();
+    dbg!(header);
 }

src/vcd/types.rs

@@ -3,16 +3,16 @@ use chrono::prelude::*;
 use num::BigInt;
 
 #[derive(Debug)]
-struct Version(String);
+pub(super) struct Version(String);
 
 #[derive(Debug)]
-enum Timescale {ps, ns, us, ms, s, unit}
+pub(super) enum Timescale {ps, ns, us, ms, s, unit}
 
 #[derive(Debug)]
 pub(super) struct Metadata {
-    date      : Option<DateTime<Utc>>,
-    version   : Option<Version>,
-    timescale : (Option<u32>, Timescale)}
+    pub(super) date      : Option<DateTime<Utc>>,
+    pub(super) version   : Option<Version>,
+    pub(super) timescale : (Option<u32>, Timescale)}
 
 #[derive(Debug)]
 struct Scope_Idx(usize);