implement better checking and errors

src/main.rs

@@ -1,23 +1,41 @@
-use lexer::Token;
-use logos::Lexer;
-use logos::Logos;
+use codespan_reporting::files::SimpleFiles;
+use codespan_reporting::term;
+use codespan_reporting::term::termcolor::ColorChoice;
+use codespan_reporting::term::termcolor::StandardStream;
 use syntax::parse_syntax;
-use utils::ws;
-use winnow::prelude::*;
-use winnow::Parser;
 
-use crate::syntax::check_syntax;
+use crate::syntax::check::check;
 
 mod lexer;
 mod syntax;
 mod utils;
 
 fn main() {
-    // valid
-    let input = "load \"./image.png\" | invert | save \"./image_processed.jpg\"";
-    dbg!(parse_syntax(input));
+    let mut files = SimpleFiles::new();
+    let mut out_errs = Vec::new();
+
+    let invalid_toks = "meow | gay $ error!\\";
+    let invalid_toks_id = files.add("invalid_toks", invalid_toks);
+    if let Err(err) = parse_syntax(invalid_toks, invalid_toks_id) {
+        out_errs.push(err)
+    }
+
+    let invalid_no_streamer = "| invert | save \"./image_processed.jpg\"";
+    let invalid_no_streamer_id = files.add("invalid_no_streamer", invalid_no_streamer);
+    if let Err(mut errs) = check(
+        parse_syntax(invalid_no_streamer, invalid_no_streamer_id).unwrap(),
+        invalid_no_streamer,
+        invalid_no_streamer_id,
+    ) {
+        out_errs.append(&mut errs)
+    }
 
     // invalid
-    let invalid_no_streamer = "| invert | save \"./image_processed.jpg\"";
-    check_syntax(parse_syntax(invalid_no_streamer), invalid_no_streamer)
+    let writer = StandardStream::stderr(ColorChoice::Always);
+    let config = term::Config::default();
+
+    for err in out_errs {
+        let writer = &mut writer.lock();
+        term::emit(writer, &config, &files, &err.to_diagnostic()).unwrap();
+    }
 }

src/syntax/check.rs

@@ -0,0 +1,34 @@
+use super::{
+    error::{FileId, SyntaxError},
+    PipelineElement, PipelineElementKind,
+};
+
+pub fn check(
+    syntax: Vec<PipelineElement>,
+    raw_source: &str,
+    file_id: FileId,
+) -> Result<Vec<PipelineElement>, Vec<SyntaxError>> {
+    let mut errs = Vec::new();
+
+    if let Err(e_span) = check_missing_streamer(&syntax) {
+        errs.push(SyntaxError::MissingStreamer(vec![(file_id, e_span)]));
+    }
+
+    if errs.is_empty() {
+        Ok(syntax)
+    } else {
+        Err(errs)
+    }
+}
+
+fn check_missing_streamer(syntax: &Vec<PipelineElement>) -> Result<(), logos::Span> {
+    if let Some(&PipelineElement {
+        kind: PipelineElementKind::Pipe,
+        ref span,
+    }) = syntax.first()
+    {
+        Err(span.clone())
+    } else {
+        Ok(())
+    }
+}

src/syntax/error.rs

@@ -0,0 +1,48 @@
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+
+pub type FileId = usize;
+
+/// The enum representing a syntax error, used for error reporting
+#[derive(Debug, Clone)]
+pub enum SyntaxError {
+    /// This variant indicates a token that the Lexer didn't recognize
+    InvalidToken(Vec<(FileId, logos::Span)>),
+    /// `MissingStreamer` means, that the pipeline starts with a Pipe (`|`), so it has no streamer as input in front of it.
+    MissingStreamer(Vec<(FileId, logos::Span)>),
+    /// `MissingSink` means, that the pipeline ends with a Pipe (`|`), meaning that the output can't go anywhere
+    MissingSink,
+    /// This indicates a missing filter somewhere in the pipeline, meaning that there's 2 pipes after one another
+    MissingFilter,
+    /// A literal cannot be a sink
+    LiteralAsSink,
+    /// A literal can't be a filter either
+    LiteralAsFilter,
+    /// A literal acting as streamer cannot take arguments
+    LiteralWithArgs,
+}
+
+impl SyntaxError {
+    pub fn to_diagnostic(&self) -> Diagnostic<usize> {
+        match self {
+            Self::InvalidToken(errs) => Diagnostic::error()
+                .with_message("failed to parse invalid tokens")
+                .with_labels(
+                    errs.into_iter()
+                        .map(|(file_id, span)| {
+                            Label::primary(*file_id, span.clone()).with_message("invalid token")
+                        })
+                        .collect(),
+                ),
+            Self::MissingStreamer(locs) => Diagnostic::error()
+                .with_message("pipelines must always start with a streamer")
+                .with_labels(
+                    locs.into_iter()
+                        .map(|(file_id, span)| {
+                            Label::primary(*file_id, span.clone()).with_message("missing streamer")
+                        })
+                        .collect(),
+                ),
+            _ => todo!(),
+        }
+    }
+}

src/syntax/mod.rs

@@ -1,19 +1,16 @@
-use core::panic;
 use std::mem;
 
-use codespan_reporting::diagnostic::Diagnostic;
-use codespan_reporting::diagnostic::Label;
-use codespan_reporting::files::Files;
-use codespan_reporting::files::SimpleFile;
-use codespan_reporting::files::SimpleFiles;
-use codespan_reporting::term;
-use codespan_reporting::term::termcolor::ColorChoice;
-use codespan_reporting::term::termcolor::StandardStream;
 use logos::Logos;
 use logos::Span;
 
 use crate::lexer::Token;
 
+use self::error::FileId;
+use self::error::SyntaxError;
+
+pub mod check;
+mod error;
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct PipelineElement {
     kind: PipelineElementKind,
@@ -40,8 +37,9 @@ pub enum CommandPartKind {
     String(String),
 }
 
-pub fn parse_syntax(input: &str) -> Vec<PipelineElement> {
+pub fn parse_syntax(input: &str, file_id: FileId) -> Result<Vec<PipelineElement>, SyntaxError> {
     let lexer = Token::lexer(input);
+    let mut errs = Vec::new();
 
     let mut r = Vec::new();
 
@@ -85,7 +83,7 @@ pub fn parse_syntax(input: &str) -> Vec<PipelineElement> {
                 _ => {}
             }
         } else {
-            panic!("Error at {span:?}")
+            errs.push((file_id, span))
         }
     }
 
@@ -98,34 +96,9 @@ pub fn parse_syntax(input: &str) -> Vec<PipelineElement> {
         });
     }
 
-    r
-}
-
-pub fn check_syntax(syntax: Vec<PipelineElement>, raw_source: &str) {
-    let mut files = SimpleFiles::new();
-    let file_id = files.add("input", raw_source);
-
-    if let Some(PipelineElement {
-        kind: PipelineElementKind::Pipe,
-        span,
-    }) = syntax.first()
-    {
-        let err = Diagnostic::error()
-            .with_message("Missing streamer for pipeline")
-            .with_labels(vec![
-                Label::primary(file_id, 0..span.end).with_message("expected streamer")
-            ])
-            .with_notes(vec!["a pipeline can't start with a pipe".to_string()]);
-
-        let writer = StandardStream::stderr(ColorChoice::Always);
-        let config = codespan_reporting::term::Config::default();
-
-        term::emit(&mut writer.lock(), &config, &files, &err).unwrap();
+    if errs.is_empty() {
+        Ok(r)
+    } else {
+        Err(SyntaxError::InvalidToken(errs))
     }
 }
-
-#[test]
-fn test_simple_parse_pipeline() {
-    let test_pipeline = "load ./image.png | invert | save ./image_processed.jpg";
-    parse_syntax(test_pipeline);
-}