Merge pull request #310 from Shopify/translate-pattern-matching-opera…

…tors Translate pattern matching operators
Shopify · Oct 28, 2024 · f1e5aea · f1e5aea
2 parents bc8caf7 + 69fba23
commit f1e5aea
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Showing 3 changed files with 310 additions and 2 deletions.
diff --git a/parser/prism/Translator.cc b/parser/prism/Translator.cc
@@ -777,6 +777,22 @@ unique_ptr<parser::Node> Translator::translate(pm_node_t *node) {
 
             return make_unique<parser::MatchCurLine>(location, move(regex));
         }
+        case PM_MATCH_REQUIRED_NODE: {
+            auto matchRequiredNode = down_cast<pm_match_required_node>(node);
+
+            auto value = patternTranslate(matchRequiredNode->value);
+            auto pattern = patternTranslate(matchRequiredNode->pattern);
+
+            return make_unique<parser::MatchPattern>(location, move(value), move(pattern));
+        }
+        case PM_MATCH_PREDICATE_NODE: {
+            auto matchPredicateNode = down_cast<pm_match_predicate_node>(node);
+
+            auto value = patternTranslate(matchPredicateNode->value);
+            auto pattern = patternTranslate(matchPredicateNode->pattern);
+
+            return make_unique<parser::MatchPatternP>(location, move(value), move(pattern));
+        }
         case PM_MATCH_WRITE_NODE: { // A regex match that assigns to a local variable, like `a =~ /wat/`
             auto matchWriteNode = down_cast<pm_match_write_node>(node);
 
@@ -1186,8 +1202,6 @@ unique_ptr<parser::Node> Translator::translate(pm_node_t *node) {
             unreachable("Prism's parser never produces `PM_SCOPE_NODE` nodes.");
 
         case PM_IMPLICIT_NODE:
-        case PM_MATCH_PREDICATE_NODE:
-        case PM_MATCH_REQUIRED_NODE:
         case PM_MISSING_NODE:
             auto type_id = PM_NODE_TYPE(node);
             auto type_name = pm_node_type_to_str(type_id);

diff --git a/test/prism_regression/pattern_matching_operators.parse-tree.exp b/test/prism_regression/pattern_matching_operators.parse-tree.exp
@@ -0,0 +1,266 @@
+Begin {
+  stmts = [
+    MatchPatternP {
+      lhs = Send {
+        receiver = NULL
+        method = <U match>
+        args = [
+        ]
+      }
+      rhs = Integer {
+        val = "1"
+      }
+    }
+    MatchPatternP {
+      lhs = Send {
+        receiver = NULL
+        method = <U no_match>
+        args = [
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          Integer {
+            val = "1"
+          }
+          Integer {
+            val = "2"
+          }
+        ]
+      }
+    }
+    MatchPatternP {
+      lhs = Array {
+        elts = [
+          Send {
+            receiver = NULL
+            method = <U match_1>
+            args = [
+            ]
+          }
+          Send {
+            receiver = NULL
+            method = <U match_2>
+            args = [
+            ]
+          }
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          Integer {
+            val = "1"
+          }
+          Integer {
+            val = "2"
+          }
+        ]
+      }
+    }
+    MatchPatternP {
+      lhs = Integer {
+        val = "1"
+      }
+      rhs = MatchVar {
+        name = <U var>
+      }
+    }
+    MatchPatternP {
+      lhs = Array {
+        elts = [
+          Integer {
+            val = "1"
+          }
+          Integer {
+            val = "2"
+          }
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          MatchVar {
+            name = <U var_a>
+          }
+          MatchVar {
+            name = <U var_b>
+          }
+        ]
+      }
+    }
+    If {
+      condition = Send {
+        receiver = LVar {
+          name = <U d>
+        }
+        method = <U ==>
+        args = [
+          Send {
+            receiver = LVar {
+              name = <U c>
+            }
+            method = <U *>
+            args = [
+              Integer {
+                val = "2"
+              }
+            ]
+          }
+        ]
+      }
+      then_ = MatchPatternP {
+        lhs = Array {
+          elts = [
+            Integer {
+              val = "3"
+            }
+            Integer {
+              val = "4"
+            }
+          ]
+        }
+        rhs = ArrayPattern {
+          elts = [
+            MatchVar {
+              name = <U c>
+            }
+            MatchVar {
+              name = <U d>
+            }
+          ]
+        }
+      }
+      else_ = NULL
+    }
+    MatchPattern {
+      lhs = Send {
+        receiver = NULL
+        method = <U match>
+        args = [
+        ]
+      }
+      rhs = Integer {
+        val = "10"
+      }
+    }
+    MatchPattern {
+      lhs = Send {
+        receiver = NULL
+        method = <U no_match>
+        args = [
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          Integer {
+            val = "10"
+          }
+          Integer {
+            val = "20"
+          }
+        ]
+      }
+    }
+    MatchPattern {
+      lhs = Array {
+        elts = [
+          Send {
+            receiver = NULL
+            method = <U match_1>
+            args = [
+            ]
+          }
+          Send {
+            receiver = NULL
+            method = <U match_2>
+            args = [
+            ]
+          }
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          Integer {
+            val = "10"
+          }
+          Integer {
+            val = "20"
+          }
+        ]
+      }
+    }
+    MatchPattern {
+      lhs = Integer {
+        val = "10"
+      }
+      rhs = MatchVar {
+        name = <U var_c>
+      }
+    }
+    MatchPattern {
+      lhs = Array {
+        elts = [
+          Integer {
+            val = "10"
+          }
+          Integer {
+            val = "20"
+          }
+        ]
+      }
+      rhs = ArrayPattern {
+        elts = [
+          MatchVar {
+            name = <U var_c>
+          }
+          MatchVar {
+            name = <U var_d>
+          }
+        ]
+      }
+    }
+    If {
+      condition = Send {
+        receiver = LVar {
+          name = <U var_d>
+        }
+        method = <U ==>
+        args = [
+          Send {
+            receiver = LVar {
+              name = <U var_c>
+            }
+            method = <U *>
+            args = [
+              Integer {
+                val = "2"
+              }
+            ]
+          }
+        ]
+      }
+      then_ = MatchPattern {
+        lhs = Array {
+          elts = [
+            Integer {
+              val = "30"
+            }
+            Integer {
+              val = "40"
+            }
+          ]
+        }
+        rhs = ArrayPattern {
+          elts = [
+            MatchVar {
+              name = <U var_c>
+            }
+            MatchVar {
+              name = <U var_d>
+            }
+          ]
+        }
+      }
+      else_ = NULL
+    }
+  ]
+}
diff --git a/test/prism_regression/pattern_matching_operators.rb b/test/prism_regression/pattern_matching_operators.rb
@@ -0,0 +1,28 @@
+# typed: false
+
+# matching expressions to patterns
+match in 1
+no_match in 1, 2
+[match_1, match_2] in 1, 2
+
+# assigning expressions to patterns
+1 in var
+[1, 2] in var_a, var_b
+
+# guards don't work outside of case-based pattern matching
+# so this should be normal conditional assignment
+[3, 4] in c, d if d == c*2
+
+
+# matching expressions to patterns
+match => 10
+no_match => 10, 20
+[match_1, match_2] => 10, 20
+
+# assigning expressions to patterns
+10 => var_c
+[10, 20] => var_c, var_d
+
+# guards don't work outside of case-based pattern matching
+# so this should be normal conditional assignment
+[30, 40] => var_c, var_d if var_d == var_c*2