added escape_cpp_keyword filter

Author: iliabylich

README.md

@@ -103,6 +103,7 @@ By default the following filters are available:
 + `| camelcase_to_snakecase` - converts `FooBar` string to `foo_bar`
 + `| snakecase_to_camelcase` - converts `foo_bar` string to `FooBar`
 + `| escape_c_keyword` - appends `_` to a string if it's a C keyword
++ `| escape_cpp_keyword` - appends `_` to a string if it's a C++ keyword
 + `| escape_rust_keyword` - appends `_` to a string if it's a Rust keyword
 + `| render_comment: "//", 4` - renders array of strings (like `node.comment`) to a string where each line is prefixed with "//" and has 4 spaces padding (except for the first line, it has no padding)
 

src/filters/escape_cpp_keyword.rs

@@ -0,0 +1,24 @@
+use liquid_core::Result;
+use liquid_core::Runtime;
+use liquid_core::{Display_filter, Filter, FilterReflection, ParseFilter};
+use liquid_core::{Value, ValueView};
+
+#[derive(Clone, ParseFilter, FilterReflection)]
+#[filter(
+    name = "escape_cpp_keyword",
+    description = "Escape C++ keyword by adding trailing _",
+    parsed(EscapeCppKeywordFilter)
+)]
+pub struct EscapeCppKeyword;
+
+#[derive(Debug, Default, Display_filter)]
+#[name = "escape_cpp_keyword"]
+struct EscapeCppKeywordFilter;
+
+impl Filter for EscapeCppKeywordFilter {
+    fn evaluate(&self, input: &dyn ValueView, _runtime: &dyn Runtime) -> Result<Value> {
+        let name = input.to_kstr();
+        let output = crate::helpers::escape_cpp_keyword(&name);
+        Ok(Value::scalar(output))
+    }
+}

src/filters/mod.rs

@@ -13,6 +13,9 @@ pub use escape_rust_keyword::EscapeRustKeyword;
 mod escape_c_keyword;
 pub use escape_c_keyword::EscapeCKeyword;
 
+mod escape_cpp_keyword;
+pub use escape_cpp_keyword::EscapeCppKeyword;
+
 pub fn invalid_input<S>(cause: S) -> liquid_core::Error
 where
     S: Into<liquid_core::model::KString>,
@@ -27,5 +30,6 @@ pub(crate) fn all() -> Vec<Box<dyn liquid_core::parser::ParseFilter>> {
         crate::filters::SnakecaseToCamelcase.into(),
         crate::filters::EscapeRustKeyword.into(),
         crate::filters::EscapeCKeyword.into(),
+        crate::filters::EscapeCppKeyword.into(),
     ]
 }

src/helpers.rs

@@ -76,3 +76,18 @@ fn test_escape_c_keyword() {
     assert_eq!(escape_c_keyword("foo"), "foo");
     assert_eq!(escape_c_keyword("default"), "default_");
 }
+
+pub fn escape_cpp_keyword(s: &str) -> String {
+    match s {
+        "default" | "operator" | "else" | "const" | "and" | "break" | "case" | "class"
+        | "false" | "float" | "for" | "if" | "int" | "or" | "return" | "true" | "while"
+        | "ERANGE" => format!("{}_", s),
+        _ => s.to_string(),
+    }
+}
+
+#[test]
+fn test_escape_cpp_keyword() {
+    assert_eq!(escape_cpp_keyword("foo"), "foo");
+    assert_eq!(escape_cpp_keyword("default"), "default_");
+}