Fix incorrect parsing of strings containing verus!{ (#72)

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Unreleased
 
+* Fix incorrect parsing of string literals containing "verus!{"
 * Support automatic formatting of the `seq!` macro
 
 # v0.3.4

src/verus-minimal.pest

@@ -20,6 +20,31 @@ COMMENT = @{
   | ("//" ~ (!NEWLINE ~ ANY)* ~ NEWLINE)
 }
 
+string = @{
+  "\"" ~ ("\\\"" | !"\"" ~ ANY)* ~ "\""
+}
+
+raw_string = @{
+  "r" ~ PUSH("#"*) ~ "\""    // push the number signs onto the stack
+  ~ raw_string_interior
+  ~ "\"" ~ POP               // match a quotation mark and the number signs
+}
+raw_string_interior = {
+  (
+      !("\"" ~ PEEK)    // unless the next character is a quotation mark
+                        // followed by the correct amount of number signs,
+      ~ ANY             // consume one character
+  )*
+}
+
+byte_string = @{
+  "b" ~ string
+}
+
+raw_byte_string = @{
+  "b" ~ raw_string
+}
+
 multiline_comment = @{
     "/*" ~ (multiline_comment | (!"*/" ~ ANY))* ~ "*/"
 }
@@ -34,7 +59,7 @@ file = {
 
 /// Region of code that doesn't contain any Verus macro use whatsoever
 non_verus = @{
-  (!("verus!" ~ WHITESPACE* ~ "{") ~ ANY)*
+  (!("verus!" ~ WHITESPACE* ~ "{") ~ (string | raw_string | byte_string | raw_byte_string | ANY))*
 }
 
 /// An actual use of the `verus! { ... }` macro

src/verus.pest

@@ -72,9 +72,9 @@ file = {
 /// someone might define a macro-rules macro _outside_ the verus! macro, but use
 /// a verus! inside of the macro body itself, to generate Verus code; if that
 /// happens, then we need to make sure that we aren't accidentally starting
-/// parsing in the middle of the macro_rules macro body itself.
+/// parsing in the middle of the macro_rules macro body itself. Similarly, strings.
 non_verus = @{
-  (!("verus!" ~ WHITESPACE* ~ "{") ~ (macro_rules | ANY))*
+  (!("verus!" ~ WHITESPACE* ~ "{") ~ (macro_rules | string | raw_string | byte_string | raw_byte_string | ANY))*
 }
 
 /// An actual use of the `verus! { ... }` macro

tests/rustfmt-matching.rs

@@ -430,3 +430,13 @@ fn test() {
 "#;
     compare(file);
 }
+
+#[test]
+fn rust_verus_bang_in_string() {
+    let file = r#"
+fn test() {
+    println!("verus!{{{}}}", "Hello");
+}
+"#;
+    compare(file);
+}