Add single quote strings, quote escaping

demo/demo.rpy

@@ -4,6 +4,9 @@ what the heck
 "this is a string with a # comment"
 "this is a string over
 multiple lines"
+"this is \"escaped\""
+'this is a single quote string'
+'this also has escaped \'quotes\''
 this is cool # comment
 
 huh

src/lib.rs

@@ -19,11 +19,22 @@ pub fn parse(file_path: &str) {
                 for token in line.into_inner() {
                     match token.as_rule() {
                         Rule::token => {
-                            println!("{}", token.as_str());
+                            let token = token.into_inner().next().unwrap();
+                            match token.as_rule() {
+                                Rule::string => {
+                                    let string_data = token.into_inner().next().unwrap();
+                                    let str = string_data.as_str();
+                                    println!("string: {}", match string_data.as_rule() {
+                                        Rule::single_quote_string_data => str.replace("\\'", "'"),
+                                        Rule::double_quote_string_data => str.replace("\\\"", "\""),
+                                        _ => unreachable!(),
+                                    });
+                                },
+                                Rule::keyword => println!("keyword: {}", token.as_str()),
+                                _ => unreachable!(),
+                            };
                         },
-                        _ => {
-                            println!("{}", token.as_str());
-                        }
+                        _ => unreachable!(),
                     }
                 }
                 println!()

src/rpy.pest

@@ -13,10 +13,18 @@ token = { string | keyword }
 // has to be atomic for no implicit separate (spaces)
 keyword = @{ (!(WHITESPACE | NEWLINE) ~ ANY)+ }
 
-// strings cannot contain quotes
-// TODO: escaped quotes
-string_data = @{ (!"\"" ~ ANY)* }
-string = ${ "\"" ~ string_data ~ "\"" }
+single_quote_string_data = @{ (
+    "\\'" // Escaped single quotes
+    | (!"'" ~ ANY)
+)* }
+double_quote_string_data = @{ (
+    "\\\"" // Escaped double quotes
+    | (!"\"" ~ ANY)
+)* }
+string = ${
+    ("'" ~ single_quote_string_data ~ "'")
+    | ("\"" ~ double_quote_string_data ~ "\"")
+}
 
 // comments are a # followed by
 // any number of non-newline characters