Created synonym 'integral' for 'integrate'

kalk/src/interpreter.rs

@@ -364,7 +364,7 @@ pub(crate) fn eval_fn_call_expr(
 
             return Ok(sum);
         }
-        "integrate" | "∫" => {
+        "integrate" | "integral" | "∫" => {
             // Make sure exactly 3 arguments were supplied.
             if expressions.len() != 3 {
                 return Err(CalcError::IncorrectAmountOfArguments(

kalk/src/parser.rs

@@ -504,7 +504,9 @@ fn parse_identifier(context: &mut Context) -> Result<Expr, CalcError> {
     if !parse_as_var_instead && match_token(context, TokenKind::OpenParenthesis) {
         advance(context);
 
-        let is_integral = identifier.full_name == "integrate" || identifier.full_name == "∫";
+        let is_integral = identifier.full_name == "integrate"
+            || identifier.full_name == "integral"
+            || identifier.full_name == "∫";
         if is_integral {
             context.is_in_integral = true;
         }

kalk/src/prelude/mod.rs

@@ -159,6 +159,7 @@ pub fn is_prelude_func(identifier: &str) -> bool {
     identifier == "sum"
         || identifier == "Σ"
         || identifier == "integrate"
+        || identifier == "integral"
         || identifier == "∫"
         || UNARY_FUNCS.contains_key(identifier)
         || BINARY_FUNCS.contains_key(identifier)

kalk_cli/src/repl.rs

@@ -112,6 +112,7 @@ lazy_static! {
         m.insert("gamma", "Γ");
         m.insert("sum", "Σ()");
         m.insert("integrate", "∫()");
+        m.insert("integral", "∫()");
         m.insert("phi", "ϕ");
         m.insert("pi", "π");
         m.insert("sqrt", "√");