From 7a8ab3d571cdc94ef2e5fc4a1e2281d4f99c76ac Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Thu, 18 Nov 2021 15:17:47 -0800
Subject: [PATCH] Full ast parsing

---
 schala-lang/src/parsing/combinator.rs | 49 ++++++++++++++++++++++-----
 schala-lang/src/parsing/mod.rs        |  6 ++++
 schala-lang/src/parsing/test.rs       | 20 +++++++++--
 3 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index f708d8e..a44c133 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -79,6 +79,22 @@ fn statement_delimiter(input: Span) -> ParseResult<()> {
     tok(alt((value((), line_ending), value((), char(';')))))(input)
 }
 
+pub fn program(input: Span) -> ParseResult<AST> {
+    let id = fresh_id(&input);
+    //TODO `rest` should be empty
+    let (rest, statements) = context("AST",
+        map(
+        tuple((
+            many0(statement_delimiter),
+            separated_list0(statement_delimiter, statement),
+            many0(statement_delimiter),
+        )), |(_, items, _)| items.into())
+    )(input)?;
+
+    let ast = AST { id, statements };
+    Ok((rest, ast))
+}
+
 pub fn block(input: Span) -> ParseResult<Block> {
     context(
         "block",
@@ -97,16 +113,33 @@ pub fn block(input: Span) -> ParseResult<Block> {
 
 fn statement(input: Span) -> ParseResult<Statement> {
     let (input, pos) = position(input)?;
-    let pos: usize = pos.location_offset();
+    let location = pos.location_offset().into();
     let id = fresh_id(&input);
-    context(
+    let (rest, kind) = context(
         "Parsing-statement",
-        map(expression, move |expr| Statement {
-            id,
-            location: pos.into(),
-            kind: StatementKind::Expression(expr),
-        }),
-    )(input)
+        alt((
+        map(expression, StatementKind::Expression),
+        map(declaration, StatementKind::Declaration),
+        ))
+    )(input)?;
+    Ok((rest, Statement { id, location, kind }))
+}
+
+fn declaration(input: Span) -> ParseResult<Declaration> {
+    alt((binding, module))(input)
+}
+
+fn binding(input: Span) -> ParseResult<Declaration> {
+    let parser = 
+    tuple((kw("let"), opt(kw("mut")), tok(identifier), opt(type_anno), tok(char('=')), expression));
+    map(parser, |(_, maybe_mut, ident, type_anno, _, expr)|
+        Declaration::Binding { name: rc_string(ident.fragment()), constant: maybe_mut.is_none(),
+        type_anno, expr })(input)
+}
+
+fn module(input: Span) -> ParseResult<Declaration> {
+    map(tuple((kw("module"), tok(identifier), block)),
+    |(_, name, items)| Declaration::Module { name: rc_string(name.fragment()), items })(input)
 }
 
 pub fn expression(input: Span) -> ParseResult<Expression> {
diff --git a/schala-lang/src/parsing/mod.rs b/schala-lang/src/parsing/mod.rs
index 8cc2365..72debf0 100644
--- a/schala-lang/src/parsing/mod.rs
+++ b/schala-lang/src/parsing/mod.rs
@@ -28,6 +28,12 @@ impl Parser {
         peg_parser::schala_parser::program(input, self).map_err(ParseError::from_peg)
     }
 
+    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)));
+        combinator::program(span).map_err(|err| convert_err(input, err)).map(|(_, output)| output)
+    }
+
     #[cfg(test)]
     fn expression(&mut self, input: &str) -> Result<Expression, ParseError> {
         peg_parser::schala_parser::expression(input, self).map_err(ParseError::from_peg)
diff --git a/schala-lang/src/parsing/test.rs b/schala-lang/src/parsing/test.rs
index fa4f9be..0e6e08b 100644
--- a/schala-lang/src/parsing/test.rs
+++ b/schala-lang/src/parsing/test.rs
@@ -98,6 +98,20 @@ macro_rules! assert_ast {
     };
 }
 
+
+macro_rules! assert_ast_comb {
+    ($input:expr, $statements:expr) => {
+        let mut parser = Parser::new();
+        let ast = parser.parse_comb($input);
+        let expected = AST { id: Default::default(), statements: $statements.into() };
+        if ast.is_err() {
+            println!("Parse error: {}", ast.unwrap_err().msg);
+            panic!();
+        }
+        assert_eq!(ast.unwrap(), expected);
+    };
+}
+
 macro_rules! assert_fail {
     ($input:expr, $failure:expr) => {
         let mut parser = Parser::new();
@@ -180,7 +194,7 @@ fn binexps() {
     use StatementKind::Expression;
 
     assert_expr_comb!("0xf_f+1", binop("+", expr(NatLiteral(255)), expr(NatLiteral(1))));
-    assert_ast!(
+    assert_ast_comb!(
         "3; 4; 4.3",
         vec![
             stmt(Expression(expr(NatLiteral(3)))),
@@ -1315,7 +1329,7 @@ fn blocks() {
 
     let mut parser = Parser::new();
     for case in cases.iter() {
-        let block = parser.block(case);
+        let block = parser.block_comb(case);
         assert_eq!(block.unwrap(), vec![exst(Value(qn!(a)))].into());
     }
 
@@ -1397,7 +1411,7 @@ fn comments() {
     assert_fail_expr!(source, binop("+", expr(NatLiteral(1)), expr(NatLiteral(2))));
 
     let source = "5//no man\n";
-    assert_ast!(source, vec![exst(NatLiteral(5))]);
+    assert_ast_comb!(source, vec![exst(NatLiteral(5))]);
 }
 
 //TODO support backtick operators like this