From ab931de08f9421d1852aa37ca29f6c95749d4bd0 Mon Sep 17 00:00:00 2001
From: Alain Zscheile <fogti+devel@ytrizja.de>
Date: Fri, 3 Nov 2023 15:28:03 +0100
Subject: [PATCH] rust: 'official' yanais record and pattern syntax

---
 rust/crates/yanais-syntax/src/lib.rs          |  5 ++--
 .../src/pat.rs                                | 26 ++++++++++++-------
 rust/crates/yanais-syntax/src/record.rs       |  2 +-
 rust/crates/yn-mrwy57u-core/src/lib.rs        |  4 +--
 4 files changed, 21 insertions(+), 16 deletions(-)
 rename rust/crates/{yn-mrwy57u-core => yanais-syntax}/src/pat.rs (57%)

diff --git a/rust/crates/yanais-syntax/src/lib.rs b/rust/crates/yanais-syntax/src/lib.rs
index b6cd689..3457bac 100644
--- a/rust/crates/yanais-syntax/src/lib.rs
+++ b/rust/crates/yanais-syntax/src/lib.rs
@@ -9,6 +9,7 @@ use miette::{Diagnostic, SourceSpan};
 use std::sync::Arc;
 
 pub mod lex;
+pub mod pat;
 pub mod record;
 
 #[macro_export]
@@ -251,8 +252,8 @@ impl<'a, Kw> Env<'a, Kw> {
     }
 }
 
-pub trait Keywords: Sized + core::str::FromStr {}
-impl<T: Sized + core::str::FromStr> Keywords for T {}
+pub trait Keywords: Sized + core::cmp::PartialEq + core::str::FromStr {}
+impl<T: Sized + core::cmp::PartialEq + core::str::FromStr> Keywords for T {}
 
 pub trait Parse<Kw: Keywords>: Sized {
     fn parse(env: &mut Env<'_, Kw>) -> Result<Self>;
diff --git a/rust/crates/yn-mrwy57u-core/src/pat.rs b/rust/crates/yanais-syntax/src/pat.rs
similarity index 57%
rename from rust/crates/yn-mrwy57u-core/src/pat.rs
rename to rust/crates/yanais-syntax/src/pat.rs
index 2fa0f80..9d3963d 100644
--- a/rust/crates/yn-mrwy57u-core/src/pat.rs
+++ b/rust/crates/yanais-syntax/src/pat.rs
@@ -4,27 +4,31 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-use crate::parser::{lex, Env as ParseEnv, Error, ErrorCtx, MaybeParse, ParseDefaultCtx};
+use crate::{
+    lex, record::Record, Env as ParseEnv, Error, ErrorCtx, EvEqSourceSpan, Keywords, MaybeParse,
+    Parse, ParseDefaultCtx,
+};
 use std::sync::Arc;
-use yanais_syntax::EvEqSourceSpan;
 
 // infallible patterns
 
 #[derive(Clone, Debug, PartialEq)]
 pub enum Pattern {
+    Ignore(EvEqSourceSpan),
     Name(EvEqSourceSpan, Arc<str>),
-    // Record(Record<Pattern>),
+    Record(Record<Pattern>),
 }
 
 impl Pattern {
     pub fn alloc_slots(&self) -> usize {
         match self {
+            Pattern::Ignore(_) => 0,
             Pattern::Name(_, x) => {
-                if x.is_empty() {
-                    0
-                } else {
-                    1
-                }
+                assert!(!x.is_empty());
+                1
+            }
+            Pattern::Record(rcd) => {
+                rcd.fields.iter().map(|(_, i)| i.alloc_slots()).sum()
             }
         }
     }
@@ -34,8 +38,8 @@ impl ParseDefaultCtx for Pattern {
     const DFL_CTX: ErrorCtx = ErrorCtx::Pattern;
 }
 
-impl MaybeParse<lex::Kw> for Pattern {
-    fn maybe_parse(env: &mut ParseEnv<'_>) -> Result<Option<Self>, Error> {
+impl<Kw: Keywords> MaybeParse<Kw> for Pattern {
+    fn maybe_parse(env: &mut ParseEnv<'_, Kw>) -> Result<Option<Self>, Error> {
         let mut nxtlxr = env.lxr.clone();
         let lex::Token {
             kind,
@@ -47,7 +51,9 @@ impl MaybeParse<lex::Kw> for Pattern {
 
         use lex::TokenKind as Tk;
         let ret = match kind {
+            Tk::PatOut(nam) if nam.is_empty() => Pattern::Ignore(tok_span),
             Tk::PatOut(nam) => Pattern::Name(tok_span, nam),
+            Tk::LBrace => return Record::parse(env).map(|i| Some(Pattern::Record(i))),
             _ => return Ok(None),
         };
         env.lxr = nxtlxr;
diff --git a/rust/crates/yanais-syntax/src/record.rs b/rust/crates/yanais-syntax/src/record.rs
index 03b799f..7af81bf 100644
--- a/rust/crates/yanais-syntax/src/record.rs
+++ b/rust/crates/yanais-syntax/src/record.rs
@@ -13,7 +13,7 @@ use crate::{
     Keywords, MaybeParse, Parse, ParseDefaultCtx, Result as Pres,
 };
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Record<V> {
     pub span: EvEqSourceSpan,
     pub fields: Vec<(Option<Arc<str>>, V)>,
diff --git a/rust/crates/yn-mrwy57u-core/src/lib.rs b/rust/crates/yn-mrwy57u-core/src/lib.rs
index 4d38c33..be3cd23 100644
--- a/rust/crates/yn-mrwy57u-core/src/lib.rs
+++ b/rust/crates/yn-mrwy57u-core/src/lib.rs
@@ -58,12 +58,10 @@ pub mod parser {
 use parser::lex::Kw;
 
 mod expr;
-mod pat;
 mod record;
 
 pub use expr::Expr;
-pub use pat::Pattern;
-pub use yanais_syntax::{record::Record, EvEqSourceSpan};
+pub use yanais_syntax::{pat::Pattern, record::Record, EvEqSourceSpan};
 
 #[derive(Clone, Debug)]
 pub struct Lambda {