Hook up core pretty-printer to CLI

Author: wezm

fathom/src/core/pretty.rs

@@ -8,7 +8,7 @@
 //! use codespan_reporting::term::termcolor::{BufferedStandardStream, ColorChoice};
 //! use fathom::core::pretty::Context;
 //! use fathom::core::Module;
-//! use fathom::StringInterner;
+//! use fathom::source::StringInterner;
 //! use std::cell::RefCell;
 //! use std::io::Write;
 //!
@@ -28,7 +28,7 @@ use pretty::RcDoc;
 use std::cell::RefCell;
 
 use crate::core::{Item, Module, Term};
-use crate::{StringId, StringInterner};
+use crate::source::{StringId, StringInterner};
 
 /// Term precedences
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
@@ -307,9 +307,12 @@ impl<'interner, 'arena> Context<'interner> {
                             self.term_prec(Prec::Top, body_expr),
                         ])
                     })
-                    .chain(default_expr.iter().map(|default| {
+                    .chain(default_expr.iter().map(|&(name, default)| {
                         RcDoc::concat([
-                            RcDoc::text("_"),
+                            match name {
+                                Some(name) => self.string_id(name),
+                                None => RcDoc::text("_"),
+                            },
                             RcDoc::space(),
                             RcDoc::text("=>"),
                             RcDoc::space(),

fathom/src/driver.rs

@@ -5,8 +5,8 @@ use std::cell::RefCell;
 use std::io::Read;
 use std::path::Path;
 
-use crate::core::binary;
-use crate::core::binary::{BufferError, ReadError};
+use crate::core;
+use crate::core::binary::{self, BufferError, ReadError};
 use crate::source::{ByteRange, FileId, Span, StringInterner};
 use crate::surface::{self, elaboration};
 use crate::BUG_REPORT_URL;
@@ -189,7 +189,7 @@ impl<'surface, 'core> Driver<'surface, 'core> {
         }
     }
 
-    pub fn elaborate_and_emit_module(&mut self, file_id: FileId) -> Status {
+    pub fn elaborate_and_emit_module(&mut self, file_id: FileId, pretty_core: bool) -> Status {
         let mut context = elaboration::Context::new(&self.interner, &self.core_scope);
 
         let surface_module = self.parse_module(file_id);
@@ -201,6 +201,9 @@ impl<'surface, 'core> Driver<'surface, 'core> {
         if *self.seen_errors.borrow() && !self.allow_errors {
             return Status::Error;
         }
+        if pretty_core {
+            self.emit_core_module(&module);
+        }
 
         self.surface_scope.reset(); // Reuse the surface scope for distillation
         let context = context.distillation_context(&self.surface_scope);
@@ -348,6 +351,15 @@ impl<'surface, 'core> Driver<'surface, 'core> {
         self.emit_doc(context.module(module).into_doc());
     }
 
+    fn emit_core_module(&self, module: &core::Module<'_>) {
+        let context = core::pretty::Context::new(&self.interner);
+        // TODO: Ideally this would be a call to emit_doc
+        let doc = context.module(module);
+        let mut emit_writer = self.emit_writer.borrow_mut();
+        writeln!(emit_writer, "{}", doc.pretty(self.emit_width)).unwrap();
+        emit_writer.flush().unwrap();
+    }
+
     fn emit_term(&self, term: &surface::Term<'_, ()>) {
         let context = surface::pretty::Context::new(&self.interner, &self.surface_scope);
         self.emit_doc(context.term(term).into_doc());

fathom/src/main.rs

@@ -28,6 +28,9 @@ enum Cli {
         /// Continue even if errors were encountered
         #[clap(long = "allow-errors")]
         allow_errors: bool,
+        /// Pretty print core module
+        #[clap(long = "pretty-core", conflicts_with("TERM_FILE"))]
+        pretty_core: bool,
     },
     /// Normalise a Fathom term, printing its normal form and type
     Norm {
@@ -139,6 +142,7 @@ fn main() -> ! {
             module_file,
             term_file,
             allow_errors,
+            pretty_core,
         } => {
             let mut driver = fathom::Driver::new();
             driver.install_panic_hook();
@@ -148,7 +152,7 @@ fn main() -> ! {
             let status = match (module_file, term_file) {
                 (Some(module_file), None) => {
                     let file_id = load_file_or_exit(&mut driver, module_file);
-                    driver.elaborate_and_emit_module(file_id)
+                    driver.elaborate_and_emit_module(file_id, pretty_core)
                 }
                 (None, Some(term_file)) => {
                     let file_id = load_file_or_exit(&mut driver, term_file);

tests/cmd/fathom-elab.md

@@ -17,6 +17,7 @@ OPTIONS:
         --term <TERM_FILE>        Path to a term to elaborate
         --allow-errors            Continue even if errors were encountered
     -h, --help                    Print help information
+        --pretty-core             Pretty print core module
 
 ```
 
@@ -35,6 +36,7 @@ OPTIONS:
         --term <TERM_FILE>        Path to a term to elaborate
         --allow-errors            Continue even if errors were encountered
     -h, --help                    Print help information
+        --pretty-core             Pretty print core module
 
 ```