Improve error detection and messages (#81)

Improve the error ranges when mistakes are made in code blocks.

Fix a colon character being interpreted as marking a procedure
declaration if found in an step.

Implement better detection of invalid attribute assignments, including a
new error variant for that case.

Hide the _language_ subcommand from main `--help` output. The command is
still there, and not "undocumented" but a human users will never need to
invoke it directly so there's no need to clutter the terminal with it.

Author: istathar

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "technique"
-version = "0.4.3"
+version = "0.4.5"
 edition = "2021"
 description = "A domain specific language for procedures."
 authors = [ "Andrew Cowie" ]

Cargo.toml

@@ -487,6 +487,9 @@ impl TechniqueLanguageServer {
                 ParsingError::InvalidSubstep(_, _) => {
                     ("Invalid substep".to_string(), DiagnosticSeverity::ERROR)
                 }
+                ParsingError::InvalidAttribute(_, _) => {
+                    ("Invalid attribute assignment".to_string(), DiagnosticSeverity::ERROR)
+                }
                 ParsingError::InvalidResponse(_, _) => {
                     ("Invalid response".to_string(), DiagnosticSeverity::ERROR)
                 }

src/editor/server.rs

@@ -165,6 +165,20 @@ pub fn render_procedure_declaration<'i>(procedure: &'i Procedure, renderer: &dyn
     render_fragments(&sub.fragments, renderer)
 }
 
+pub fn render_scope<'i>(scope: &'i Scope, renderer: &dyn Render) -> String {
+    let mut sub = Formatter::new(78);
+    match scope {
+        Scope::AttributeBlock { attributes, .. } => {
+            // Render attributes without indentation for error messages
+            sub.append_attributes(attributes);
+        }
+        _ => {
+            panic!("Do not use for anything other than rendering Attribute line examples");
+        }
+    }
+    render_fragments(&sub.fragments, renderer)
+}
+
 /// Helper function to convert fragments to a styled string using a renderer
 fn render_fragments<'i>(fragments: &[(Syntax, Cow<'i, str>)], renderer: &dyn Render) -> String {
     let mut result = String::new();
@@ -806,6 +820,7 @@ impl<'i> Formatter<'i> {
                 attributes,
                 subscopes,
             } => {
+                self.indent();
                 self.append_attributes(attributes);
                 self.add_fragment_reference(Syntax::Newline, "\n");
 
@@ -906,7 +921,6 @@ impl<'i> Formatter<'i> {
     }
 
     fn append_attributes(&mut self, attributes: &'i Vec<Attribute>) {
-        self.indent();
         for (i, attribute) in attributes
             .iter()
             .enumerate()

src/formatting/formatter.rs

@@ -129,6 +129,7 @@ fn main() {
         .subcommand(
             Command::new("language")
                 .about("Language Server Protocol integration for editors and IDEs.")
+                .hide(true)
                 .long_about("Run a Language Server Protocol (LSP) service \
                    for Technique documents. This accepts commands and code \
                    input via stdin and returns compilation errors and other \

src/main.rs

@@ -246,7 +246,7 @@ making_coffee :
     1. Do something { re peat() }
             "#
         .trim_ascii(),
-        ParsingError::InvalidFunction(39, 7),
+        ParsingError::InvalidCodeBlock(39, 10),
     );
 }
 
@@ -259,7 +259,7 @@ making_coffee :
     1. Do something { re peat <thing>() }
             "#
         .trim_ascii(),
-        ParsingError::InvalidFunction(39, 15),
+        ParsingError::InvalidCodeBlock(39, 18),
     );
 }