From a00125d4a5224c3a3ab706b9287549d02710d539 Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Sat, 13 Nov 2021 13:45:52 -0800
Subject: [PATCH] Make string literals work properly

---
 schala-lang/language/src/ast/mod.rs      |  1 +
 schala-lang/language/src/parsing/new.rs  | 13 ++++++++++---
 schala-lang/language/src/parsing/test.rs | 19 +++++++++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/schala-lang/language/src/ast/mod.rs b/schala-lang/language/src/ast/mod.rs
index 90dcb54..2d9495e 100644
--- a/schala-lang/language/src/ast/mod.rs
+++ b/schala-lang/language/src/ast/mod.rs
@@ -197,6 +197,7 @@ pub struct TypeSingletonName {
 pub enum ExpressionKind {
     NatLiteral(u64),
     FloatLiteral(f64),
+    //TODO StringLiteral variant needs to support prefixes
     StringLiteral(Rc<String>),
     BoolLiteral(bool),
     BinExp(BinOp, Box<Expression>, Box<Expression>),
diff --git a/schala-lang/language/src/parsing/new.rs b/schala-lang/language/src/parsing/new.rs
index 134ef15..8f516ae 100644
--- a/schala-lang/language/src/parsing/new.rs
+++ b/schala-lang/language/src/parsing/new.rs
@@ -435,12 +435,19 @@ peg::parser! {
                 }
             }
 
+        //TODO need to do something with prefix in the AST
         rule string_literal() -> ExpressionKind =
-            s:bare_string_literal(){ ExpressionKind::StringLiteral(Rc::new(s.to_string())) }
+            prefix:identifier()? s:bare_string_literal(){ ExpressionKind::StringLiteral(Rc::new(s.to_string())) }
 
-        //TODO string escapes, prefixes
         rule bare_string_literal() -> &'input str =
-            "\"" items:$([^ '"' ]*) "\"" { items }
+            "\"" s:$(string_component()*) "\"" { s }
+
+        rule string_component() -> &'input str =
+            r#"\\"# { "\\" } /
+            r#"\""# { "\"" } /
+            r#"\t"# { "\t" } /
+            r#"\n"# { "\n" } /
+            ch:$([^ '"' ]) { ch }
 
         rule bool_literal() -> ExpressionKind =
             "true" { ExpressionKind::BoolLiteral(true) } / "false" { ExpressionKind::BoolLiteral(false) }
diff --git a/schala-lang/language/src/parsing/test.rs b/schala-lang/language/src/parsing/test.rs
index fab7538..e47d6ae 100644
--- a/schala-lang/language/src/parsing/test.rs
+++ b/schala-lang/language/src/parsing/test.rs
@@ -135,7 +135,17 @@ fn basic_literals() {
     assert_expr!("0xf_f_", expr(NatLiteral(255)));
     assert_expr!("false", expr(BoolLiteral(false)));
     assert_expr!("true", expr(BoolLiteral(true)));
+}
+
+#[test]
+fn string_literals() {
+    use ExpressionKind::*;
+
+    assert_expr!(r#""""#, expr(StringLiteral(rc(""))));
     assert_expr!(r#""hello""#, expr(StringLiteral(rc("hello"))));
+    assert_expr!(r#"b"some bytestring""#, expr(StringLiteral(rc("some bytestring"))));
+    //NOTE I'm not 100% sure this case is correct, but I'll deal with it later
+    assert_expr!(r#""Do \n \" escapes work\t""#, expr(StringLiteral(rc(r#"Do \n \" escapes work\t"#))));
 }
 
 #[test]
@@ -1309,3 +1319,12 @@ fn comments() {
     let source = "5//no man\n";
     assert_ast!(source, vec![exst(NatLiteral(5))]);
 }
+
+//TODO support backtick operators like this
+/*
+#[test]
+fn backtick_operators() {
+    let output = token_kinds("1 `plus` 2");
+    assert_eq!(output, vec![digit!("1"), op!("plus"), digit!("2")]);
+}
+*/