Transofrmation

example.mlc

@@ -1,5 +1,5 @@
-#with language.toml
 variable:=-3; c := (a+b- 3) * 23 + variable; d := c - a;Natural : Number (n) := {n >= 0};faculty : Natural (n) -> Natural := if n = 0 then 1 else faculty (n-1) * n end;
 String Natural (n) := {Character * n};hello_word -> String := "Hello World!";
 first_letter -> Character := 'a';
 wrong -> Logic := false;date -> String := "#date_now";
+user -> String := "#user"

language.toml

@@ -10,6 +10,7 @@ comments = ["^--.*", ""]
 [meta.interpolation]
 with = ["^#with ([\\w./]+)", "cat $1"]
 date = ["#date_now", "date"]
+user = ["#user", "user"]
 
 # Describes tokens to be replaced by identifiers and then later swapped back in after the tokenizer.
 # All special tokens are treated as constants

src/preprocessor.rs

@@ -125,9 +125,20 @@ impl MetaRules {
             println!("[INFO] Applying rule {}", rule.0);
             let base_pattern: Regex = Regex::new((rule.1 .0).as_str()).unwrap();
             let processed_code_replacement = processed_code.clone();
-            let parameter = &base_pattern
+            let parameter = if &base_pattern
                 .captures(processed_code_replacement.as_str())
-                .unwrap()[0];
+                .unwrap()
+                .len()
+                > 0
+            {
+                &base_pattern
+                    .captures(processed_code_replacement.as_str())
+                    .unwrap()[0]
+            } else {
+                &base_pattern
+                    .captures(processed_code_replacement.as_str())
+                    .unwrap()
+            };
             let command: &str = &base_pattern.replace(parameter, rule.1 .1.as_str());
             println!("{:?}", &command);
             let subprocess = std::process::Command::new("/bin/bash")