From a03f57026699a6e34c291f2e0b996336a1d4f24b Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Tue, 26 Oct 2021 00:39:24 -0700
Subject: [PATCH] More tuple pattern work

---
 TODO.md                                       |  1 +
 schala-lang/language/src/parsing/test.rs      | 50 ++++++++++++++++++-
 schala-lang/language/src/reduced_ir/mod.rs    |  7 ++-
 schala-lang/language/src/reduced_ir/types.rs  |  1 +
 .../language/src/tree_walk_eval/mod.rs        |  6 +++
 .../language/src/tree_walk_eval/test.rs       | 15 ++++++
 6 files changed, 77 insertions(+), 3 deletions(-)

diff --git a/TODO.md b/TODO.md
index ba412e1..71a63cb 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,6 +3,7 @@
 ## Testing
 
 * Get a test library for running many unit tests working
+* Write a human-readable display of the AST
 
 ## Symbols
 
diff --git a/schala-lang/language/src/parsing/test.rs b/schala-lang/language/src/parsing/test.rs
index 5ec8826..68c390f 100644
--- a/schala-lang/language/src/parsing/test.rs
+++ b/schala-lang/language/src/parsing/test.rs
@@ -830,6 +830,55 @@ fn if_expr() {
   }
 }
 
+#[test]
+fn advanced_if_expr() {
+
+    parse_test_wrap_ast! {
+        r#"
+if (45, "panda", false, 2.2) {
+    is (49, "pablo", _, 28.4) then "no"
+    is (_, "panda", _, -2.2) then "yes"
+    is _ then "maybe"
+}"#,
+      exst!(
+        IfExpression {
+          discriminator: Some(bx!(ex!(s r#"(45, "panda", false, 2.2)"#))),
+          body: bx!(IfExpressionBody::CondList(vec![
+            ConditionArm {
+              condition: Condition::Pattern(Pattern::TuplePattern(
+                vec![
+                    Pattern::Literal(PatternLiteral::NumPattern { neg: false, num: NatLiteral(49) }),
+                    Pattern::Literal(PatternLiteral::StringPattern(rc!(pablo))),
+                    Pattern::Ignored,
+                    Pattern::Literal(PatternLiteral::NumPattern { neg: false, num: FloatLiteral(28.4) }),
+                ]
+              )),
+              guard: None,
+              body: vec![exst!(s r#""no""#)],
+            },
+            ConditionArm {
+              condition: Condition::Pattern(Pattern::TuplePattern(
+                vec![
+                    Pattern::Ignored,
+                    Pattern::Literal(PatternLiteral::StringPattern(rc!(panda))),
+                    Pattern::Ignored,
+                    Pattern::Literal(PatternLiteral::NumPattern { neg: true, num: FloatLiteral(2.2) }),
+                ]
+              )),
+              guard: None,
+              body: vec![exst!(s r#""yes""#)],
+            },
+            ConditionArm {
+              condition: Condition::Pattern(Pattern::Ignored),
+              guard: None,
+              body: vec![exst!(s r#""maybe""#)],
+            },
+          ]))
+        }
+      )
+    }
+}
+
 #[test]
 fn modules() {
   parse_test_wrap_ast! {
@@ -890,4 +939,3 @@ fn annotations() {
         }
     };
 }
-
diff --git a/schala-lang/language/src/reduced_ir/mod.rs b/schala-lang/language/src/reduced_ir/mod.rs
index 68e3641..fbf76ae 100644
--- a/schala-lang/language/src/reduced_ir/mod.rs
+++ b/schala-lang/language/src/reduced_ir/mod.rs
@@ -311,8 +311,11 @@ impl ast::Pattern {
             ast::Pattern::Ignored => {
                 Pattern::Ignored
             },
-            ast::Pattern::TuplePattern(/*Vec<Pattern>*/..) => {
-                unimplemented!()
+            ast::Pattern::TuplePattern(subpatterns) => {
+                let pats: Vec<_> = subpatterns.iter().map(|pat| pat.reduce(symbol_table)).collect();
+                let pats: Result<Vec<Pattern>, PatternError> = pats.into_iter().collect();
+                let pats = pats?;
+                Pattern::Tuple(pats)
             },
             ast::Pattern::Literal(lit) => Pattern::Literal(match lit {
                 ast::PatternLiteral::NumPattern { neg, num } =>  match (neg, num) {
diff --git a/schala-lang/language/src/reduced_ir/types.rs b/schala-lang/language/src/reduced_ir/types.rs
index bf52baa..55bf303 100644
--- a/schala-lang/language/src/reduced_ir/types.rs
+++ b/schala-lang/language/src/reduced_ir/types.rs
@@ -125,6 +125,7 @@ pub struct Alternative {
 
 #[derive(Debug, Clone)]
 pub enum Pattern {
+    Tuple(Vec<Pattern>),
     Literal(Literal),
     Ignored,
 }
diff --git a/schala-lang/language/src/tree_walk_eval/mod.rs b/schala-lang/language/src/tree_walk_eval/mod.rs
index a673ba6..c1d7fb9 100644
--- a/schala-lang/language/src/tree_walk_eval/mod.rs
+++ b/schala-lang/language/src/tree_walk_eval/mod.rs
@@ -284,6 +284,11 @@ impl<'a> State<'a> {
               } else {
                   false
               },
+              Pattern::Tuple(subpatterns) => match scrut {
+                  Primitive::Tuple(items) if items.len() == subpatterns.len() =>
+                      items.iter().zip(subpatterns.iter()).all(|(item, subpat)| matches(item, subpat)),
+                  _ => false //TODO should be a type error
+              }
           }
       }
       let cond = self.expression(cond)?;
@@ -413,6 +418,7 @@ impl<'a> State<'a> {
               (BooleanNot, Lit(Bool(false))) => Bool(true),
               (Negate, Lit(Nat(n))) => Int(-(*n as i64)),
               (Negate, Lit(Int(n))) => Int(-(*n as i64)),
+              (Negate, Lit(Float(f))) => Float(-(*f as f64)),
               (Increment, Lit(Int(n))) => Int(*n),
               (Increment, Lit(Nat(n))) => Nat(*n),
               _ => return Err("No valid prefix op".into())
diff --git a/schala-lang/language/src/tree_walk_eval/test.rs b/schala-lang/language/src/tree_walk_eval/test.rs
index 82cea92..99e02c7 100644
--- a/schala-lang/language/src/tree_walk_eval/test.rs
+++ b/schala-lang/language/src/tree_walk_eval/test.rs
@@ -116,6 +116,21 @@ if x {
     eval_assert(&source, expected);
 }
 
+#[test_case(r#"(45, "panda", false, 2.2)"#, r#""yes""#)]
+#[test_case(r#"(99, "panda", false, -2.45)"#, r#""maybe""#)]
+fn tuple_patterns(input: &str, expected: &str) {
+    let mut source = format!("let x = {}", input);
+    source.push_str(r#"
+if x {
+    is (45, "pablo", _, 28.4) then "no"
+    is (_, "panda", _, 2.2) then "yes"
+    is _ then "maybe"
+}"#);
+println!("{}", source);
+
+    eval_assert(&source, expected);
+}
+
 #[test]
 fn if_is_patterns() {
   let source = r#"