Fix poly_func display impl

CQCL · Oct 17, 2024 · 6204324 · 6204324
1 parent a0a986a
commit 6204324
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Showing 3 changed files with 16 additions and 7 deletions.
diff --git a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_func.snap b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_func.snap
@@ -3,7 +3,7 @@ source: hugr-core/src/hugr/views/tests.rs
 expression: h.dot_string()
 ---
 digraph {
-0 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(0) FuncDefn: "test"</td></tr></table>>]
+0 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(0) FuncDefn: "test"</td></tr><tr><td port="out0" align="text" colspan="1" cellpadding="1" >0: [[]+[]] -&gt; [[]][[]+[]]</td></tr></table>>]
 1 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(1) Input</td></tr><tr><td port="out0" align="text" colspan="1" cellpadding="1" >0: []+[]</td></tr></table>>]
 1:out0 -> 2:in0 [style=""]
 2 [shape=plain label=<<table border="1"><tr><td port="in0" align="text" colspan="1" cellpadding="1" >0: []+[]</td></tr><tr><td align="text" border="0" colspan="1">(2) Output</td></tr></table>>]

diff --git a/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_module.snap b/hugr-core/src/hugr/views/snapshots/hugr_core__hugr__views__tests__dot_module.snap
@@ -4,7 +4,7 @@ expression: h.dot_string()
 ---
 digraph {
 0 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(0) Module</td></tr></table>>]
-1 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(1) FuncDecl: "test"</td></tr><tr><td port="out0" align="text" colspan="1" cellpadding="1" >0: forall params.iter().map(ToString::to_string).join(" "). body</td></tr></table>>]
+1 [shape=plain label=<<table border="1"><tr><td align="text" border="0" colspan="1">(1) FuncDecl: "test"</td></tr><tr><td port="out0" align="text" colspan="1" cellpadding="1" >0: [[]+[]] -&gt; [[]][[]+[]]</td></tr></table>>]
 hier0 [shape=plain label="0"]
 hier0 -> hier1  [style = "dashed"] 
 hier1 [shape=plain label="1"]

diff --git a/hugr-core/src/types/poly_func.rs b/hugr-core/src/types/poly_func.rs
@@ -1,5 +1,7 @@
 //! Polymorphic Function Types
 
+use itertools::Itertools;
+
 use crate::extension::{ExtensionRegistry, SignatureError};
 #[cfg(test)]
 use {
@@ -22,11 +24,7 @@ use super::{signature::FuncTypeBase, MaybeRV, NoRV, RowVariable};
     Clone, PartialEq, Debug, Eq, Hash, derive_more::Display, serde::Serialize, serde::Deserialize,
 )]
 #[cfg_attr(test, derive(Arbitrary), proptest(params = "RecursionDepth"))]
-#[display(
-    "forall {}. {}",
-    "params.iter().map(ToString::to_string).join(\" \")",
-    "body"
-)]
+#[display("{}{body}", self.display_params())]
 pub struct PolyFuncTypeBase<RV: MaybeRV> {
     /// The declared type parameters, i.e., these must be instantiated with
     /// the same number of [TypeArg]s before the function can be called. This
@@ -136,6 +134,17 @@ impl<RV: MaybeRV> PolyFuncTypeBase<RV> {
         // TODO https://github.com/CQCL/hugr/issues/624 validate TypeParams declared here, too
         self.body.validate(reg, &self.params)
     }
+
+    /// Helper function for the Display implementation
+    fn display_params(&self) -> String {
+        if self.params.is_empty() {
+            return String::new();
+        }
+        format!(
+            "forall {}. ",
+            self.params.iter().map(ToString::to_string).join(" ")
+        )
+    }
 }
 
 #[cfg(test)]