readable errors

src/main.rs

@@ -37,7 +37,7 @@ fn main() {
     let specs = &args[2..];
     let src = || std::fs::read_to_string(&args[0]).unwrap();
     match args[1].to_lowercase().trim() {
-        "html" => println!(
+        "html" => print!(
             "{}",
             to::html::page(&parse(&src()).unwrap(), specs, &mut to::html::State::new())
         ),
@@ -122,7 +122,13 @@ const BODY_REGEX = new RegExp("<bo"+"dy>.*<\\/bo"+"dy>", "misv");
                     }
                     buf1[i] = src();
                     let src = unsafe { &*((&buf1[i]) as *const String) };
-                    buf2[i] = Some(parse(src).unwrap());
+                    buf2[i] = Some(match parse(src) {
+                        Ok(v) => v,
+                        Err(e) => {
+                            eprintln!("{}", e.display(src));
+                            continue;
+                        }
+                    });
                     let doc = unsafe { &*(buf2[i].as_ref().unwrap() as *const Document<'_>) };
                     i += 1;
                     let mut http =

src/parse.rs

@@ -1,3 +1,5 @@
+use std::fmt::Display;
+
 use crate::doc::{Component, Document, Section, Text};
 
 pub fn parse<'a>(mut src: &'a str) -> Result<Document<'a>, ParseError<'a>> {
@@ -6,6 +8,8 @@ pub fn parse<'a>(mut src: &'a str) -> Result<Document<'a>, ParseError<'a>> {
     Ok(doc)
 }
 
+#[derive(Debug)]
+pub struct ParseErrorPlus<'a>(ParseErr<'a>, usize, &'a str);
 #[derive(Debug)]
 pub struct ParseError<'a>(ParseErr<'a>, usize);
 #[derive(Debug)]
@@ -20,7 +24,7 @@ pub enum ParseErr<'a> {
     MissingClosing(char),
     InvalidBacktickBracketCountSpecifier,
     InvalidBacktickModifier,
-    SubsectionNotAllowedHere,
+    SubdocumentNotAllowedHere,
     FileTitleWithLink,
     r#__Zzzz(&'a str),
 }
@@ -371,7 +375,7 @@ fn parse_sections<'a>(
                 // => section hashes
                 Some(' ' | '\n') | None => {
                     if !document {
-                        return Err(ParseError(ParseErr::SubsectionNotAllowedHere, pos));
+                        return Err(ParseError(ParseErr::SubdocumentNotAllowedHere, pos));
                     }
                     src.reset_to(pos);
                     match parse_document(src.get(), depth + 1)
@@ -517,3 +521,67 @@ impl<'a, 'b> Parser<'a, 'b> {
         }
     }
 }
+
+impl<'a> ParseError<'a> {
+    pub fn display(self, src: &'a str) -> ParseErrorPlus<'a> {
+        ParseErrorPlus(self.0, self.1, src)
+    }
+}
+impl<'a> Display for ParseErrorPlus<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let ln = self
+            .2
+            .char_indices()
+            .take_while(|(i, _)| *i <= self.1)
+            .filter(|(_, c)| *c == '\n')
+            .count();
+        write!(f, "Line {}: {}", ln + 1, self.0)
+    }
+}
+impl<'a> Display for ParseErr<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ParseErr::InvalidSectionHash => write!(
+                f,
+                "this section hash isn't valid, if you want a title, add a space after your hashtags"
+            ),
+            ParseErr::InvalidHeadingDepth => write!(f, "this heading depth isn't allowed here"),
+            ParseErr::BracketsAtStartOfSectionWithNoLinebreakAfter => write!(
+                f,
+                "brackets at the start of a section must be on their own line"
+            ),
+            ParseErr::BracketedSectionNotTerminated => {
+                write!(f, "this bracketed section isn't terminated anywhere")
+            }
+            ParseErr::BracketedSectionTerminatedByTooManyBrackets => write!(
+                f,
+                "this bracketed section is terminated by more brackets than expected"
+            ),
+            ParseErr::IncompleteBacktick => {
+                write!(
+                    f,
+                    "incomplete backtick, there needs to be something here (or escape the backtick: ``)"
+                )
+            }
+            ParseErr::MissingClosing(c) => {
+                write!(f, "couldn't find an appropriate closing {c} bracket")
+            }
+            ParseErr::InvalidBacktickBracketCountSpecifier => write!(
+                f,
+                "invalid backtick bracket count between ` and the next ascii symbol"
+            ),
+            ParseErr::InvalidBacktickModifier => write!(
+                f,
+                "invalid backtick modifier between ` and the next bracket"
+            ),
+            ParseErr::SubdocumentNotAllowedHere => {
+                write!(f, "found a subdocument where it isn't allowed")
+            }
+            ParseErr::FileTitleWithLink => write!(
+                f,
+                "file title (title at the start of the file) cannot have a link"
+            ),
+            ParseErr::__Zzzz(_) => unreachable!(),
+        }
+    }
+}

src/to/html.rs

@@ -7,15 +7,13 @@ use crate::{
 
 pub struct State<'a> {
     pub head_to_body: &'a str,
-    cache_docs: BTreeMap<&'a Document<'a>, String>,
+    cache: BTreeMap<&'a Section<'a>, String>,
-    cache_secs: BTreeMap<&'a Section<'a>, String>,
 }
 impl<'a> State<'a> {
     pub fn new() -> Self {
         State {
             head_to_body: "</head>\n<body>",
-            cache_docs: Default::default(),
+            cache: Default::default(),
-            cache_secs: Default::default(),
         }
     }
 }
@@ -254,11 +252,6 @@ fn doc_to_impl<'a>(
     out: &mut String,
     doc_args: &mut DocArgs<'a, '_>,
 ) {
-    if let Some(prev) = doc_args.state.cache_docs.get(doc) {
-        out.push_str(prev);
-        return;
-    }
-    let out_start = out.len();
     let depth = doc_args.depth;
     let end_at = doc_args.max_len.map(|len| out.len() + len);
     for d in depth..=doc.depth {
@@ -285,7 +278,7 @@ fn doc_to_impl<'a>(
         out.push_str(&format!("</span>{a}</div>\n"));
     }
     for section in &doc.sections {
-        if let Some(prev) = doc_args.state.cache_secs.get(section) {
+        if let Some(prev) = doc_args.state.cache.get(section) {
             out.push_str(prev);
             continue;
         }
@@ -385,16 +378,12 @@ fn doc_to_impl<'a>(
         out.push_str("</div>\n");
         doc_args
             .state
-            .cache_secs
+            .cache
             .insert(section, out[section_start..].to_owned());
     }
     for _ in depth..=doc.depth {
         out.push_str("</div>\n");
     }
-    doc_args
-        .state
-        .cache_docs
-        .insert(doc, out[out_start..].to_owned());
 }
 
 fn text_to<'a: 'b, 'b>(