DEV: Fix escaping in both strings and format strings.

docsite/site/content/reference/expressions.md

@@ -320,6 +320,12 @@ let tpl = {
 "foo.bar.1 == @{item.foo.bar.1}" % tpl;
 ```
 
+The `@` symbol can be escaped with a double slash.
+
+```
+"https://username:password\\@@:@/" % (host, port)
+```
+
 If the `%` operator is followed by a parenthesized expression it will be treated
 as the first form with one item.
 

docsite/site/content/reference/types.md

@@ -47,6 +47,12 @@ Strings are any double quoted text. You can use the `\` to esacpe characters in
 "This is an escaped \"string\"";
 ```
 
+*Character Escapes*
+
+* '\n' is a new line
+* '\r' is a carriage return
+* '\t' is a tab
+
 ### NULL or the Empty type
 
 NULL is the empty type. It represents the absence of a value. It is represented by the

integration_tests/format_test.ucg

@@ -48,4 +48,14 @@ assert t.equal{
 assert t.equal{
     left = "@{item.op()} is just great" % {op=func() => "BOB!"},
     right = "BOB! is just great",
+};
+
+assert t.equal{
+    left = "\\@@" % (NULL),
+    right = "@NULL",
+};
+
+assert t.equal{
+    left = "\\@{foo}@{item.op()} is just great" % {op=func() => "BOB!"},
+    right = "@{foo}BOB! is just great",
 };

integration_tests/simple_values_test.ucg

@@ -0,0 +1,17 @@
+let t = import "std/testing.ucg";
+
+assert t.equal{
+    left = "foo\n",
+    right = "foo
+",
+};
+
+assert t.equal{
+    left = "foo\t",
+    right = "foo	",
+};
+
+assert t.not_equal{
+    left = "foo\\t",
+    right = "foo\\" + "\t",
+};

src/build/format.rs

@@ -67,16 +67,23 @@ impl<V: Into<String> + Clone> FormatRenderer for SimpleFormatter<V> {
                 let strval = arg.into();
                 buf.push_str(&strval);
                 count += 1;
+                should_escape = false;
             } else if c == '\\' && !should_escape {
+                eprintln!("found an escape char {}", self.tmpl);
                 should_escape = true;
             } else {
                 buf.push(c);
+                should_escape = false;
             }
         }
         if self.args.len() != count {
             return Err(error::BuildError::with_pos(
-                "Too many arguments to string \
-                 formatter.",
+                format!(
+                    "Too many arguments to string \
+                     formatter. Expected {} got {}",
+                    count,
+                    self.args.len()
+                ),
                 error::ErrorType::FormatError,
                 pos.clone(),
             )
@@ -201,10 +208,12 @@ where
                 let val = self.consume_expr(&mut self.builder.borrow_mut(), &mut iter, pos)?;
                 let strval: String = val.into();
                 buf.push_str(&strval);
+                should_escape = false;
             } else if c == '\\' && !should_escape {
                 should_escape = true;
             } else {
                 buf.push(c);
+                should_escape = false;
             }
         }
         return Ok(buf);

src/convert/yaml.rs

@@ -71,7 +71,11 @@ impl YamlConverter {
         Ok(yaml_val)
     }
 
-    fn merge_mapping_keys(&self, mut fs: &mut Vec<(String, Rc<Val>)>, m: &serde_yaml::Mapping) -> Result<(), Box<dyn Error>> {
+    fn merge_mapping_keys(
+        &self,
+        mut fs: &mut Vec<(String, Rc<Val>)>,
+        m: &serde_yaml::Mapping,
+    ) -> Result<(), Box<dyn Error>> {
         for (key, value) in m {
             // This is a little gross but since yaml allows maps to be keyed
             // by more than just a string it's necessary.
@@ -90,7 +94,6 @@ impl YamlConverter {
                 if let serde_yaml::Value::Mapping(merge_map) = value {
                     self.merge_mapping_keys(&mut fs, merge_map)?;
                 }
-
             } else {
                 fs.push((key, Rc::new(self.convert_yaml_val(&value)?)));
             }

src/tokenizer/mod.rs

@@ -49,7 +49,7 @@ fn is_symbol_char<'a>(i: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, u8> {
 
 fn escapequoted<'a>(input: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, String> {
     // loop until we find a " that is not preceded by \.
-    // Collapse all \<char> to just char  for escaping.
+    // Collapse all \<char> to just char  for escaping exept for \n \r \t and \@.
     let mut frag = String::new();
     let mut escape = false;
     let mut _input = input.clone();
@@ -58,6 +58,31 @@ fn escapequoted<'a>(input: OffsetStrIter<'a>) -> Result<OffsetStrIter<'a>, Strin
             Some(c) => *c,
             None => break,
         };
+        if escape {
+            match c as char {
+                'n' => {
+                    eprintln!("Pushing new line onto string");
+                    frag.push('\n');
+                    escape = false;
+                    continue;
+                }
+                'r' => {
+                    eprintln!("Pushing carriage return onto string");
+                    frag.push('\r');
+                    escape = false;
+                    continue;
+                }
+                't' => {
+                    eprintln!("Pushing tab onto string");
+                    frag.push('\t');
+                    escape = false;
+                    continue;
+                }
+                _ => {
+                    //noop
+                }
+            }
+        }
         if c == '\\' as u8 && !escape {
             // eat this slash and set our escaping sentinel
             escape = true;