From 9a13848f8053fb98a039fb63a9015b0068d6a7d6 Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Sat, 20 Nov 2021 02:26:22 -0800
Subject: [PATCH] Parsing refactors

---
 schala-lang/src/parsing/combinator.rs | 20 +++++++-------------
 schala-lang/src/parsing/mod.rs        | 20 +++++++++-----------
 2 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index fd2af06..740cdaf 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -18,8 +18,7 @@ use nom::{
 use nom_locate::{position, LocatedSpan};
 
 use crate::identifier::{Id, IdStore};
-
-type StoreRef = Rc<RefCell<IdStore<ASTItem>>>;
+use crate::parsing::StoreRef;
 
 pub type Span<'a> = LocatedSpan<&'a str, StoreRef>;
 type ParseResult<'a, O> = IResult<Span<'a>, O, VerboseError<Span<'a>>>;
@@ -66,11 +65,6 @@ fn fresh_id(span: &Span) -> Id<ASTItem> {
     table_handle.fresh()
 }
 
-fn fresh_id_rc(store_ref: &StoreRef) -> Id<ASTItem> {
-    let mut table_handle = store_ref.borrow_mut();
-    table_handle.fresh()
-}
-
 fn tok<'a, O>(
     input_parser: impl Parser<Span<'a>, O, VerboseError<Span<'a>>>,
 ) -> impl FnMut(Span<'a>) -> IResult<Span<'a>, O, VerboseError<Span<'a>>> {
@@ -129,17 +123,16 @@ fn statement_delimiter(input: Span) -> ParseResult<()> {
 
 pub fn program(input: Span) -> ParseResult<AST> {
     let id = fresh_id(&input);
-    //TODO `rest` should be empty
     let (rest, statements) = context(
         "AST",
         terminated(
             map(
-                tuple((
+                delimited(
                     many0(statement_delimiter),
                     separated_list0(many1(statement_delimiter), statement),
                     many0(statement_delimiter),
-                )),
-                |(_, items, _)| items.into(),
+                ),
+                |items| items.into(),
             ),
             tok(eof),
         ),
@@ -470,12 +463,12 @@ fn prefix_op(input: Span) -> ParseResult<PrefixOp> {
 
 fn prefix_expr(allow_struct: bool) -> impl FnMut(Span) -> ParseResult<ExpressionKind> {
     move |input: Span| {
-        let handle = input.extra.clone();
+        let id = fresh_id(&input);
         context(
             "prefix-expr",
             map(pair(opt(prefix_op), extended_expr(allow_struct)), move |(prefix, expr)| {
                 if let Some(prefix) = prefix {
-                    let expr = Expression::new(fresh_id_rc(&handle), expr);
+                    let expr = Expression::new(id, expr);
                     ExpressionKind::PrefixExp(prefix, Box::new(expr))
                 } else {
                     expr
@@ -968,6 +961,7 @@ impl BinopSequence {
 #[cfg(test)]
 mod test {
     use pretty_assertions::assert_eq;
+
     use super::*;
 
     macro_rules! span {
diff --git a/schala-lang/src/parsing/mod.rs b/schala-lang/src/parsing/mod.rs
index 5a2509f..93baa3f 100644
--- a/schala-lang/src/parsing/mod.rs
+++ b/schala-lang/src/parsing/mod.rs
@@ -15,13 +15,15 @@ use crate::{
     identifier::{Id, IdStore},
 };
 
+pub(crate) type StoreRef = Rc<RefCell<IdStore<ASTItem>>>;
 pub struct Parser {
-    id_store: IdStore<ASTItem>,
+    id_store: StoreRef,
 }
 
 impl Parser {
     pub(crate) fn new() -> Self {
-        Self { id_store: IdStore::new() }
+        let id_store: IdStore<ASTItem> = IdStore::new();
+        Self { id_store: Rc::new(RefCell::new(id_store)) }
     }
 
     pub(crate) fn parse(&mut self, input: &str) -> Result<AST, ParseError> {
@@ -29,14 +31,13 @@ impl Parser {
     }
 
     pub(crate) fn parse_comb(&mut self, input: &str) -> Result<AST, ParseError> {
-        let id_store: IdStore<ASTItem> = IdStore::new();
-        let span = Span::new_extra(input, Rc::new(RefCell::new(id_store)));
+        let span = Span::new_extra(input, self.id_store.clone());
         let (rest, output) = combinator::program(span).map_err(|err| convert_err(input, err))?;
 
         if rest.fragment() != &"" {
             return Err(ParseError {
                 location: Default::default(),
-                msg: format!("BAD STATE remaining string: `{}`", rest.fragment()),
+                msg: format!("Bad parse state, remaining text: `{}`", rest.fragment()),
             });
         }
 
@@ -50,9 +51,7 @@ impl Parser {
 
     #[cfg(test)]
     fn expression_comb(&mut self, input: &str) -> Result<Expression, ParseError> {
-        let id_store: IdStore<ASTItem> = IdStore::new();
-        let span = Span::new_extra(input, Rc::new(RefCell::new(id_store)));
-
+        let span = Span::new_extra(input, self.id_store.clone());
         combinator::expression(span).map_err(|err| convert_err(input, err)).map(|(rest, output)| output)
     }
 
@@ -63,13 +62,12 @@ impl Parser {
 
     #[cfg(test)]
     fn block_comb(&mut self, input: &str) -> Result<Block, ParseError> {
-        let id_store: IdStore<ASTItem> = IdStore::new();
-        let span = Span::new_extra(input, Rc::new(RefCell::new(id_store)));
+        let span = Span::new_extra(input, self.id_store.clone());
         combinator::block(span).map_err(|err| convert_err(input, err)).map(|(_, output)| output)
     }
 
     fn fresh(&mut self) -> Id<ASTItem> {
-        self.id_store.fresh()
+        self.id_store.borrow_mut().fresh()
     }
 }