fix: empty or([]) being parsed as nothing

Constant matrices inside operations were not recognised by our parser,
so were ignored. This includes expressions like or([]) and
min([1,2,3]).

- Add parsing support for constant matrices inside operations.

- Add support for top level "false" and "true" with Minion. Ideally,
  these models would never get passed to the solver; however, this would
  require solution evaluation and a refactor of our tester, so I have
  left this for future work.

Fixes #366.

conjure_oxide/src/main.rs

@@ -97,10 +97,10 @@ pub fn main() -> AnyhowResult<()> {
         .append(true)
         .open("conjure_oxide.log")?;
 
-    //Builder::with_level("Trace")
-    Builder::new()
+    Builder::with_level("TRACE")
+        //Builder::new()
         .with_target_writer("info", new_writer(stdout()))
-        .with_target_writer("file", new_writer(log_file))
+        .with_target_writer("file,jsonparser", new_writer(log_file))
         .init();
 
     if target_family != SolverFamily::Minion {

conjure_oxide/tests/integration/bugs/issue-336-empty-or-should-be-false/input.essence

@@ -0,0 +1,7 @@
+
+$ "By mathematical tradition (and Essence semantics), an 'empty or' is false, however, this model has 5 answers (one for each value of a)"
+$ -- https://github.com/conjure-cp/conjure-oxide/issues/366
+
+find a : int(1..5)
+such that
+or([])

conjure_oxide/tests/integration/bugs/issue-336-empty-or-should-be-false/input.expected-minion.solutions.json

@@ -0,0 +1 @@
+[]

conjure_oxide/tests/integration/bugs/issue-336-empty-or-should-be-false/input.expected-parse.serialised.json

@@ -0,0 +1,31 @@
+{
+  "constraints": {
+    "Or": [
+      {
+        "clean": false,
+        "etype": null
+      },
+      []
+    ]
+  },
+  "next_var": 0,
+  "variables": [
+    [
+      {
+        "UserName": "a"
+      },
+      {
+        "domain": {
+          "IntDomain": [
+            {
+              "Bounded": [
+                1,
+                5
+              ]
+            }
+          ]
+        }
+      }
+    ]
+  ]
+}

conjure_oxide/tests/integration/bugs/issue-336-empty-or-should-be-false/input.expected-rewrite.serialised.json

@@ -0,0 +1,33 @@
+{
+  "constraints": {
+    "Constant": [
+      {
+        "clean": false,
+        "etype": null
+      },
+      {
+        "Bool": false
+      }
+    ]
+  },
+  "next_var": 0,
+  "variables": [
+    [
+      {
+        "UserName": "a"
+      },
+      {
+        "domain": {
+          "IntDomain": [
+            {
+              "Bounded": [
+                1,
+                5
+              ]
+            }
+          ]
+        }
+      }
+    ]
+  ]
+}

conjure_oxide/tests/integration/bugs/yb33-min-of-constants-parses-as-nothing/input.essence

@@ -0,0 +1,5 @@
+$ the parser would read the min as Nothing...
+$ related: issue-366
+
+find c : int(1..7)
+such that min([5,7]) + c <= 10

conjure_oxide/tests/integration/bugs/yb33-min-of-constants-parses-as-nothing/input.expected-minion.solutions.json

@@ -0,0 +1,17 @@
+[
+  {
+    "UserName(c)": 1
+  },
+  {
+    "UserName(c)": 2
+  },
+  {
+    "UserName(c)": 3
+  },
+  {
+    "UserName(c)": 4
+  },
+  {
+    "UserName(c)": 5
+  }
+]

conjure_oxide/tests/integration/bugs/yb33-min-of-constants-parses-as-nothing/input.expected-parse.serialised.json

@@ -0,0 +1,94 @@
+{
+  "constraints": {
+    "Leq": [
+      {
+        "clean": false,
+        "etype": null
+      },
+      {
+        "Sum": [
+          {
+            "clean": false,
+            "etype": null
+          },
+          [
+            {
+              "Min": [
+                {
+                  "clean": false,
+                  "etype": null
+                },
+                [
+                  {
+                    "Constant": [
+                      {
+                        "clean": false,
+                        "etype": null
+                      },
+                      {
+                        "Int": 5
+                      }
+                    ]
+                  },
+                  {
+                    "Constant": [
+                      {
+                        "clean": false,
+                        "etype": null
+                      },
+                      {
+                        "Int": 7
+                      }
+                    ]
+                  }
+                ]
+              ]
+            },
+            {
+              "Reference": [
+                {
+                  "clean": false,
+                  "etype": null
+                },
+                {
+                  "UserName": "c"
+                }
+              ]
+            }
+          ]
+        ]
+      },
+      {
+        "Constant": [
+          {
+            "clean": false,
+            "etype": null
+          },
+          {
+            "Int": 10
+          }
+        ]
+      }
+    ]
+  },
+  "next_var": 0,
+  "variables": [
+    [
+      {
+        "UserName": "c"
+      },
+      {
+        "domain": {
+          "IntDomain": [
+            {
+              "Bounded": [
+                1,
+                7
+              ]
+            }
+          ]
+        }
+      }
+    ]
+  ]
+}

conjure_oxide/tests/integration/bugs/yb33-min-of-constants-parses-as-nothing/input.expected-rewrite.serialised.json

@@ -0,0 +1,54 @@
+{
+  "constraints": {
+    "SumLeq": [
+      {
+        "clean": false,
+        "etype": null
+      },
+      [
+        {
+          "Reference": [
+            {
+              "clean": false,
+              "etype": null
+            },
+            {
+              "UserName": "c"
+            }
+          ]
+        }
+      ],
+      {
+        "Constant": [
+          {
+            "clean": false,
+            "etype": null
+          },
+          {
+            "Int": 5
+          }
+        ]
+      }
+    ]
+  },
+  "next_var": 1,
+  "variables": [
+    [
+      {
+        "UserName": "c"
+      },
+      {
+        "domain": {
+          "IntDomain": [
+            {
+              "Bounded": [
+                1,
+                7
+              ]
+            }
+          ]
+        }
+      }
+    ]
+  ]
+}

conjure_oxide/tests/integration/eprime-minion/partial-eval-02-or-and/input.expected-parse.serialised.json

@@ -59,6 +59,70 @@
             ]
           ]
         },
+        {
+          "Or": [
+            {
+              "clean": false,
+              "etype": null
+            },
+            [
+              {
+                "AllDiff": [
+                  {
+                    "clean": false,
+                    "etype": null
+                  },
+                  [
+                    {
+                      "Constant": [
+                        {
+                          "clean": false,
+                          "etype": null
+                        },
+                        {
+                          "Int": 1
+                        }
+                      ]
+                    },
+                    {
+                      "Constant": [
+                        {
+                          "clean": false,
+                          "etype": null
+                        },
+                        {
+                          "Int": 2
+                        }
+                      ]
+                    },
+                    {
+                      "Constant": [
+                        {
+                          "clean": false,
+                          "etype": null
+                        },
+                        {
+                          "Int": 3
+                        }
+                      ]
+                    }
+                  ]
+                ]
+              },
+              {
+                "Constant": [
+                  {
+                    "clean": false,
+                    "etype": null
+                  },
+                  {
+                    "Bool": true
+                  }
+                ]
+              }
+            ]
+          ]
+        },
         {
           "And": [
             {