Handle - as filename indicating to read from stdin

Author: istathar

src/formatting/formatter.rs

@@ -623,7 +623,7 @@ impl<'i> Formatter<'i> {
     }
 
     // This is a helper for rendering a single descriptives in error messages.
-    // The real method is append_decriptives() below; this method simply
+    // The real method is append_descriptives() below; this method simply
     // creates a single element slice that can be passed to it.
     fn append_descriptive(&mut self, descriptive: &'i Descriptive) {
         use std::slice;

src/parsing/mod.rs

@@ -1,5 +1,6 @@
 //! parser for the Technique language
 
+use std::io::Read;
 use std::path::Path;
 use tracing::debug;
 
@@ -15,6 +16,21 @@ pub use parser::{parse_with_recovery, Parser, ParsingError};
 /// main function so that the Technique object created by parse() below can
 /// have the same lifetime.
 pub fn load(filename: &Path) -> Result<String, LoadingError<'_>> {
+    if filename.to_str() == Some("-") {
+        let mut buffer = String::new();
+        match std::io::stdin().read_to_string(&mut buffer) {
+            Ok(_) => return Ok(buffer),
+            Err(error) => {
+                debug!(?error);
+                return Err(LoadingError {
+                    problem: "Failed reading from stdin".to_string(),
+                    details: error.to_string(),
+                    filename,
+                });
+            }
+        }
+    }
+
     match std::fs::read_to_string(filename) {
         Ok(content) => Ok(content),
         Err(error) => {

src/problem/format.rs

@@ -11,6 +11,7 @@ pub fn full_parsing_error<'i>(
     renderer: &impl Render,
 ) -> String {
     let (problem, details) = generate_error_message(error, renderer);
+    let input = generate_filename(filename);
     let offset = error.offset();
     let width = error.width();
 
@@ -44,7 +45,7 @@ pub fn full_parsing_error<'i>(
 {}
         "#,
         "error".bright_red(),
-        filename.to_string_lossy(),
+        input,
         line,
         column,
         problem.bold(),
@@ -71,6 +72,7 @@ pub fn concise_parsing_error<'i>(
     renderer: &impl Render,
 ) -> String {
     let (problem, _) = generate_error_message(error, renderer);
+    let input = generate_filename(filename);
     let offset = error.offset();
     let i = calculate_line_number(source, offset);
     let j = calculate_column_number(source, offset);
@@ -80,7 +82,7 @@ pub fn concise_parsing_error<'i>(
     format!(
         "{}: {}:{}:{} {}",
         "error".bright_red(),
-        filename.to_string_lossy(),
+        input,
         line,
         column,
         problem.bold(),
@@ -101,6 +103,16 @@ pub fn concise_loading_error<'i>(error: &LoadingError<'i>) -> String {
     )
 }
 
+fn generate_filename(filename: &Path) -> String {
+    if filename.to_str() == Some("-") {
+        "<stdin>".to_string()
+    } else {
+        filename
+            .display()
+            .to_string()
+    }
+}
+
 // Helper functions for line/column calculation
 pub fn calculate_line_number(content: &str, offset: usize) -> usize {
     content[..offset]