From d3866a190821d3bc1af3c68e92d98c533615fbf8 Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Tue, 23 Nov 2021 23:56:25 -0800
Subject: [PATCH] Self

---
 schala-lang/src/ast/mod.rs            | 1 +
 schala-lang/src/ast/visitor.rs        | 7 ++++++-
 schala-lang/src/ast/visualize.rs      | 1 +
 schala-lang/src/parsing/combinator.rs | 5 +++++
 schala-lang/src/reduced_ir/mod.rs     | 1 +
 5 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/schala-lang/src/ast/mod.rs b/schala-lang/src/ast/mod.rs
index eb85983..2a9c8ac 100644
--- a/schala-lang/src/ast/mod.rs
+++ b/schala-lang/src/ast/mod.rs
@@ -208,6 +208,7 @@ pub enum ExpressionKind {
     PrefixExp(PrefixOp, Box<Expression>),
     TupleLiteral(Vec<Expression>),
     Value(QualifiedName),
+    SelfValue,
     NamedStruct { name: QualifiedName, fields: Vec<(Rc<String>, Expression)> },
     Call { f: Box<Expression>, arguments: Vec<InvocationArgument> },
     Index { indexee: Box<Expression>, indexers: Vec<Expression> },
diff --git a/schala-lang/src/ast/visitor.rs b/schala-lang/src/ast/visitor.rs
index ca6e5e5..d481e3c 100644
--- a/schala-lang/src/ast/visitor.rs
+++ b/schala-lang/src/ast/visitor.rs
@@ -71,7 +71,12 @@ pub fn walk_expression<V: ASTVisitor>(v: &mut V, expr: &Expression) {
 
     if let Recursion::Continue = v.expression(expr) {
         match &expr.kind {
-            NatLiteral(_) | FloatLiteral(_) | StringLiteral { .. } | BoolLiteral(_) | Value(_) => (),
+            NatLiteral(_)
+            | FloatLiteral(_)
+            | StringLiteral { .. }
+            | BoolLiteral(_)
+            | Value(_)
+            | SelfValue => (),
             BinExp(_, lhs, rhs) => {
                 walk_expression(v, lhs);
                 walk_expression(v, rhs);
diff --git a/schala-lang/src/ast/visualize.rs b/schala-lang/src/ast/visualize.rs
index e9bca2f..c14b5b4 100644
--- a/schala-lang/src/ast/visualize.rs
+++ b/schala-lang/src/ast/visualize.rs
@@ -45,6 +45,7 @@ fn render_expression(expr: &Expression, indent: usize, buf: &mut String) {
 
     buf.push_str("(Expr ");
     match &expr.kind {
+        SelfValue => write!(buf, "(SelfValue)").unwrap(),
         NatLiteral(n) => buf.push_str(&format!("(NatLiteral {})", n)),
         FloatLiteral(f) => buf.push_str(&format!("(FloatLiteral {})", f)),
         StringLiteral { s, prefix } => buf.push_str(&format!("(StringLiteral prefix: {:?} {})", prefix, s)),
diff --git a/schala-lang/src/parsing/combinator.rs b/schala-lang/src/parsing/combinator.rs
index 68d3ec0..7cd03b3 100644
--- a/schala-lang/src/parsing/combinator.rs
+++ b/schala-lang/src/parsing/combinator.rs
@@ -617,6 +617,7 @@ fn primary_expr_no_struct(input: Span) -> ParseResult<ExpressionKind> {
             float_literal,
             number_literal,
             string_literal,
+            self_expr,
         )),
     )(input)
 }
@@ -631,6 +632,10 @@ fn named_struct(input: Span) -> ParseResult<ExpressionKind> {
     )(input)
 }
 
+fn self_expr(input: Span) -> ParseResult<ExpressionKind> {
+    context("self-expression", map(kw("self"), |_| ExpressionKind::SelfValue))(input)
+}
+
 //TODO support anonymous structs and Elm-style update syntax for structs
 fn record_block(input: Span) -> ParseResult<Vec<(Rc<String>, Expression)>> {
     let record_entry =
diff --git a/schala-lang/src/reduced_ir/mod.rs b/schala-lang/src/reduced_ir/mod.rs
index 182d55f..e45d7bf 100644
--- a/schala-lang/src/reduced_ir/mod.rs
+++ b/schala-lang/src/reduced_ir/mod.rs
@@ -124,6 +124,7 @@ impl<'a, 'b> Reducer<'a, 'b> {
         use crate::ast::ExpressionKind::*;
 
         match &expr.kind {
+            SelfValue => panic!(),
             NatLiteral(n) => Expression::Literal(Literal::Nat(*n)),
             FloatLiteral(f) => Expression::Literal(Literal::Float(*f)),
             //TODO implement handling string literal prefixes