bugfix for builtin functions using 3-tuples

mers_lib/src/program/configs/gen/function.rs

@@ -1,4 +1,4 @@
-use std::{marker::PhantomData, sync::Arc};
+use std::marker::PhantomData;
 
 use crate::{
     data::{self, Data, MersData, Type},
@@ -59,10 +59,13 @@ pub trait StaticMersFunc: Sized + 'static + Send + Sync {
                 None => Err(CheckError::from(format!(
                     "unexpected argument of type {}, expected {}",
                     a.get().as_type().with_info(i),
-                    Type::new(data::function::FunctionT(
-                        Err(Arc::new(Self::types())),
-                        crate::info::Info::neverused()
-                    ))
+                    {
+                        let mut o = Type::empty();
+                        for t in Self::types() {
+                            o.add_all(&t.0);
+                        }
+                        o
+                    }
                     .with_info(i)
                 ))),
             }

mers_lib/src/program/configs/gen/mod.rs

@@ -288,7 +288,7 @@ impl<A: FromMersData, B: FromMersData, C: FromMersData> FromMersData for (A, B,
         if let Some(v) = d
             .as_any()
             .downcast_ref::<data::tuple::Tuple>()
-            .filter(|v| v.0.len() == 2)
+            .filter(|v| v.0.len() == 3)
         {
             A::try_represent(v.0[0].get().as_ref(), |v1| {
                 if let Some(va) = v1 {