From 3da4f02ffa31fd6dc0b61550debb40f254a050b0 Mon Sep 17 00:00:00 2001
From: JT <jonathan.d.turner@gmail.com>
Date: Mon, 9 Aug 2021 19:53:06 +1200
Subject: [PATCH] aliases

---
 src/eval.rs         |  3 ++-
 src/parser.rs       | 26 +++++++++++++++++++++-----
 src/parser_state.rs |  5 ++++-
 src/tests.rs        |  5 +++++
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/src/eval.rs b/src/eval.rs
index 20c2b71f..9876dffe 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -111,13 +111,14 @@ pub struct State<'a> {
     pub parser_state: &'a ParserState,
 }
 
+#[derive(Debug)]
 pub struct StackFrame {
     pub vars: HashMap<VarId, Value>,
     pub env_vars: HashMap<String, String>,
     pub parent: Option<Stack>,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Stack(Rc<RefCell<StackFrame>>);
 
 impl Default for Stack {
diff --git a/src/parser.rs b/src/parser.rs
index e8786248..ffbd1a88 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -2256,14 +2256,30 @@ impl<'a> ParserWorkingSet<'a> {
     pub fn parse_alias(&mut self, spans: &[Span]) -> (Statement, Option<ParseError>) {
         let name = self.get_span_contents(spans[0]);
 
-        if name == b"alias" && spans.len() >= 4 {
-            let alias_name = self.get_span_contents(spans[1]).to_vec();
-            let _equals = self.get_span_contents(spans[2]);
+        if name == b"alias" {
+            if let Some(decl_id) = self.find_decl(b"alias") {
+                let (call, call_span, _) = self.parse_internal_call(spans[0], &spans[1..], decl_id);
 
-            let replacement = spans[3..].to_vec();
+                if spans.len() >= 4 {
+                    let alias_name = self.get_span_contents(spans[1]).to_vec();
+                    let _equals = self.get_span_contents(spans[2]);
 
-            self.add_alias(alias_name, replacement);
+                    let replacement = spans[3..].to_vec();
+
+                    self.add_alias(alias_name, replacement);
+                }
+
+                return (
+                    Statement::Expression(Expression {
+                        expr: Expr::Call(call),
+                        span: call_span,
+                        ty: Type::Unknown,
+                    }),
+                    None,
+                );
+            }
         }
+
         (
             Statement::Expression(Expression {
                 expr: Expr::Garbage,
diff --git a/src/parser_state.rs b/src/parser_state.rs
index db5d721e..1b487461 100644
--- a/src/parser_state.rs
+++ b/src/parser_state.rs
@@ -9,7 +9,7 @@ pub struct ParserState {
     vars: Vec<Type>,
     decls: Vec<Declaration>,
     blocks: Vec<Block>,
-    scope: Vec<ScopeFrame>, // REMOVE
+    scope: Vec<ScopeFrame>,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -83,6 +83,9 @@ impl ParserState {
             for item in first.vars.into_iter() {
                 last.vars.insert(item.0, item.1);
             }
+            for item in first.aliases.into_iter() {
+                last.aliases.insert(item.0, item.1);
+            }
         }
     }
 
diff --git a/src/tests.rs b/src/tests.rs
index 9e130394..2397be86 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -138,3 +138,8 @@ fn floating_add() -> TestResult {
 fn subcommand() -> TestResult {
     run_test("def foo [] {}; def \"foo bar\" [] {3}; foo bar", "3")
 }
+
+#[test]
+fn alias_1() -> TestResult {
+    run_test("def foo [$x] { $x + 10 }; alias f = foo; f 100", "110")
+}