From 8aa306746ab6e5d74ad98007354921be70624574 Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Fri, 5 Nov 2021 03:08:25 -0700
Subject: [PATCH] While-parsing passing

Albeit with a lot of code duplication
---
 schala-lang/language/src/parsing/new.rs  | 61 +++++++++++++++++++++++-
 schala-lang/language/src/parsing/test.rs |  4 +-
 2 files changed, 61 insertions(+), 4 deletions(-)

diff --git a/schala-lang/language/src/parsing/new.rs b/schala-lang/language/src/parsing/new.rs
index 9f10244..ac31b1c 100644
--- a/schala-lang/language/src/parsing/new.rs
+++ b/schala-lang/language/src/parsing/new.rs
@@ -19,7 +19,7 @@ peg::parser! {
                 id: Default::default(), location: Default::default(), kind: StatementKind::Expression(expr) }
         }
 
-        rule block() -> Block = "{" items:(statement() ** delimiter()) "}" { items.into() }
+        rule block() -> Block = "{" _ items:(statement() ** delimiter()) _ "}" { items.into() }
 
         pub rule expression() -> Expression =
             _ kind:expression_kind() { Expression { id: Default::default(), type_anno: None, kind: kind } }
@@ -27,6 +27,9 @@ peg::parser! {
         rule expression_kind() -> ExpressionKind =
             precedence_expr()
 
+        rule expression_kind_no_struct() -> ExpressionKind =
+            precedence_expr_no_struct()
+
         rule precedence_expr() -> ExpressionKind =
         first:prefix_expr() _ next:(precedence_continuation())* {
             let next = next.into_iter().map(|(sigil, expr)| (BinOp::from_sigil(sigil), expr)).collect();
@@ -36,6 +39,15 @@ peg::parser! {
         rule precedence_continuation() -> (&'input str, ExpressionKind) =
             op:operator() _ expr:prefix_expr() _ { (op, expr) }
 
+        rule precedence_expr_no_struct() -> ExpressionKind =
+        first:prefix_expr() _ next:(precedence_continuation_no_struct())* {
+            let next = next.into_iter().map(|(sigil, expr)| (BinOp::from_sigil(sigil), expr)).collect();
+            BinopSequence { first, next }.do_precedence()
+        }
+
+        rule precedence_continuation_no_struct() -> (&'input str, ExpressionKind) =
+            op:operator() _ expr:prefix_expr_no_struct() _ { (op, expr) }
+
         rule prefix_expr() -> ExpressionKind =
             prefix:prefix()? expr:extended_expr() {
                 if let Some(p) = prefix {
@@ -47,6 +59,17 @@ peg::parser! {
                 }
             }
 
+        rule prefix_expr_no_struct() -> ExpressionKind =
+            prefix:prefix()? expr:extended_expr_no_struct() {
+                if let Some(p) = prefix {
+                    let expr = Expression::new(Default::default(), expr);
+                    let prefix = PrefixOp::from_sigil(p);
+                    ExpressionKind::PrefixExp(prefix, Box::new(expr))
+                } else {
+                    expr
+                }
+            }
+
         rule prefix() -> &'input str =
             $(['+' | '-' | '!' ])
 
@@ -76,6 +99,27 @@ peg::parser! {
             } } /
             primary()
 
+        #[cache_left_rec]
+        rule extended_expr_no_struct() -> ExpressionKind =
+            indexee:extended_expr() indexers:index_part() {
+                ExpressionKind::Index {
+                    indexee: Box::new(Expression::new(Default::default(), indexee)),
+                    indexers,
+                }
+            } /
+            f:extended_expr() arguments:call_part() {
+                ExpressionKind::Call {
+                    f: Box::new(Expression::new(Default::default(), f)),
+                    arguments,
+                }
+
+            } /
+            expr:extended_expr() "." name:identifier() { ExpressionKind::Access {
+                name: Rc::new(name.to_string()),
+                expr: Box::new(Expression::new(Default::default(),expr)),
+            } } /
+            primary_no_struct()
+
         rule index_part() -> Vec<Expression> =
             "[" indexers:(expression() ++ ",") "]" { indexers }
 
@@ -92,10 +136,23 @@ peg::parser! {
             _ expr:expression() _ { InvocationArgument::Positional(expr) }
 
 
+        rule primary_no_struct() -> ExpressionKind =
+            while_expr() / float_literal() / nat_literal() / bool_literal() / string_literal() / paren_expr() /
+            list_expr() / if_expr() / identifier_expr()
+
         rule primary() -> ExpressionKind =
-            float_literal() / nat_literal() / bool_literal() / string_literal() / paren_expr() /
+            while_expr() / float_literal() / nat_literal() / bool_literal() / string_literal() / paren_expr() /
             list_expr() / if_expr() / named_struct() / identifier_expr()
 
+        rule while_expr() -> ExpressionKind =
+            "while" _ cond:expression_kind_no_struct()? _ body:block() {
+                ExpressionKind::WhileExpression {
+                    condition: cond.map(|kind| Box::new(Expression::new(Default::default(), kind))),
+                    body,
+                }
+            }
+
+
         rule identifier_expr() -> ExpressionKind =
             qn:qualified_identifier() { ExpressionKind::Value(qn) }
 
diff --git a/schala-lang/language/src/parsing/test.rs b/schala-lang/language/src/parsing/test.rs
index 166845b..789d9b4 100644
--- a/schala-lang/language/src/parsing/test.rs
+++ b/schala-lang/language/src/parsing/test.rs
@@ -365,8 +365,8 @@ fn index() {
 fn while_expression() {
     use ExpressionKind::*;
 
-    assert_expr!("while { }", expr(WhileExpression { condition: None, body: Block::default() }));
-    assert_expr!(
+    assert_expr2!("while { }", expr(WhileExpression { condition: None, body: Block::default() }));
+    assert_expr2!(
         "while a == b { }",
         expr(WhileExpression {
             condition: Some(bx(binop("==", expr(Value(qn!(a))), expr(Value(qn!(b)))))),