From 20aaf1826a63bfa9be3817dce31d3bbf6483fa4f Mon Sep 17 00:00:00 2001
From: Stephen Chung <schungx@live.com>
Date: Sun, 4 Apr 2021 15:06:13 +0800
Subject: [PATCH] Fix builds.

---
 CHANGELOG.md                |  2 ++
 src/bin/rhai-repl.rs        |  1 +
 src/optimize.rs             |  2 +-
 src/packages/string_more.rs | 21 ++++-----------------
 src/parser.rs               |  1 -
 src/token.rs                |  4 +---
 tests/string.rs             | 16 ++++++++++++++++
 7 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3de6bcfc..99e9987f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,8 @@
 Rhai Release Notes
 ==================
 
+This version adds string interpolation.
+
 Version 0.19.16
 ===============
 
diff --git a/src/bin/rhai-repl.rs b/src/bin/rhai-repl.rs
index 3f556f05..a7d7cf7b 100644
--- a/src/bin/rhai-repl.rs
+++ b/src/bin/rhai-repl.rs
@@ -140,6 +140,7 @@ fn main() {
 
     // Set a file module resolver without caching
     #[cfg(not(feature = "no_module"))]
+    #[cfg(not(feature = "no_std"))]
     {
         let mut resolver = rhai::module_resolvers::FileModuleResolver::new();
         resolver.enable_cache(false);
diff --git a/src/optimize.rs b/src/optimize.rs
index 9a86e1de..ea30d5cf 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -616,7 +616,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut State) {
             if let Stmt::Expr(e) = mem::take(&mut x.statements[0]) {
                 *expr = e;
             } else {
-                unreachable!();                
+                unreachable!();
             }
         }
         // { stmt; ... } - do not count promotion as dirty because it gets turned back into an array
diff --git a/src/packages/string_more.rs b/src/packages/string_more.rs
index 4fd3062b..e2e533e3 100644
--- a/src/packages/string_more.rs
+++ b/src/packages/string_more.rs
@@ -36,14 +36,6 @@ mod string_functions {
             format!("{}{}", string, s).into()
         }
     }
-    #[rhai_fn(name = "+=")]
-    pub fn append(ctx: NativeCallContext, string: &mut ImmutableString, mut item: Dynamic) {
-        let s = print_with_func(FUNC_TO_STRING, &ctx, &mut item);
-
-        if !s.is_empty() {
-            string.make_mut().push_str(&s);
-        }
-    }
     #[rhai_fn(name = "+", pure)]
     pub fn add_prepend(
         ctx: NativeCallContext,
@@ -59,16 +51,13 @@ mod string_functions {
             s.into()
         }
     }
-    #[rhai_fn(name = "+=")]
-    pub fn prepend(ctx: NativeCallContext, item: &mut Dynamic, string: &str) {
-        let mut s = print_with_func(FUNC_TO_STRING, &ctx, item);
 
-        if !string.is_empty() {
-            s.make_mut().push_str(string);
-        }
+    #[rhai_fn(name = "+", name = "append")]
+    pub fn add_append_str(string1: ImmutableString, string2: ImmutableString) -> ImmutableString {
+        string1 + string2
     }
 
-    #[rhai_fn(name = "+")]
+    #[rhai_fn(name = "+", name = "append")]
     pub fn add_append_unit(string: ImmutableString, _item: ()) -> ImmutableString {
         string
     }
@@ -76,8 +65,6 @@ mod string_functions {
     pub fn add_prepend_unit(_item: (), string: ImmutableString) -> ImmutableString {
         string
     }
-    #[rhai_fn(name = "+=")]
-    pub fn add_append_assign_unit(_string: &mut ImmutableString, _item: ()) {}
 
     #[rhai_fn(name = "len", get = "len")]
     pub fn len(string: &str) -> INT {
diff --git a/src/parser.rs b/src/parser.rs
index 7f3a4315..96482ca6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1056,7 +1056,6 @@ fn parse_primary(
                 }
             }
 
-            println!("Interpolated string: {:?}", segments);
             Expr::InterpolatedString(Box::new(segments))
         }
 
diff --git a/src/token.rs b/src/token.rs
index 187d3726..3a64bd84 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -1,7 +1,5 @@
 //! Main module defining the lexer and parser.
 
-use std::iter::FusedIterator;
-
 use crate::engine::{
     Precedence, KEYWORD_DEBUG, KEYWORD_EVAL, KEYWORD_FN_PTR, KEYWORD_FN_PTR_CALL,
     KEYWORD_FN_PTR_CURRY, KEYWORD_IS_DEF_VAR, KEYWORD_PRINT, KEYWORD_THIS, KEYWORD_TYPE_OF,
@@ -10,7 +8,7 @@ use crate::stdlib::{
     borrow::Cow,
     cell::Cell,
     char, fmt, format,
-    iter::Peekable,
+    iter::{FusedIterator, Peekable},
     num::NonZeroUsize,
     ops::{Add, AddAssign},
     str::{Chars, FromStr},
diff --git a/tests/string.rs b/tests/string.rs
index 4428d490..9c72b27d 100644
--- a/tests/string.rs
+++ b/tests/string.rs
@@ -367,5 +367,21 @@ fn test_string_interpolated() -> Result<(), Box<EvalAltResult>> {
         "hello 42 worlds!"
     );
 
+    assert_eq!(
+        engine.eval::<String>(
+            r#"
+                let x = 42;
+                let y = 123;
+                
+                `
+Undeniable logic:
+1) Hello, ${let w = `${x} world`; if x > 1 { w += "s" } w}!
+2) If ${y} > ${x} then it is ${y > x}!
+`
+            "#
+        )?,
+        "Undeniable logic:\n1) Hello, 42 worlds!\n2) If 123 > 42 then it is true!\n",
+    );
+
     Ok(())
 }