add merge function

It does the same thing as `dict1 + dict2`, but takes any number of dicts, or a list of dicts. I think this is more readable than the `+` operator.
numbas · Dec 4, 2024 · d07f741 · d07f741
1 parent 0eb739b
commit d07f741
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Showing 4 changed files with 91 additions and 24 deletions.
diff --git a/runtime/scripts/jme-builtins.js b/runtime/scripts/jme-builtins.js
@@ -110,18 +110,29 @@ newBuiltin('+',[TList,'?'],TList, null, {
         return new TList(value);
     }
 });
-newBuiltin('+',[TDict,TDict],TDict, null,{
+
+const fn_dict_update = {
     evaluate: function(args,scope) {
         var nvalue = {};
-        Object.keys(args[0].value).forEach(function(x) {
-            nvalue[x] = args[0].value[x];
-        })
-        Object.keys(args[1].value).forEach(function(x) {
-            nvalue[x] = args[1].value[x];
-        })
+
+        if(args.length == 1 && args[0].type == 'list') {
+            args = args[0].value;
+        }
+
+        args.forEach(arg => {
+            Object.keys(arg.value).forEach(function(x) {
+                nvalue[x] = arg.value[x];
+            });
+        });
+
         return new TDict(nvalue);
     }
-});
+}
+newBuiltin('+',[TDict,TDict],TDict, null, fn_dict_update);
+
+newBuiltin('merge',['*dict'],TDict, null, fn_dict_update);
+newBuiltin('merge',['list of dict'],TDict, null, fn_dict_update);
+
 var fconc = function(a,b) { return a+b; }
 newBuiltin('+', [TString,'?'], TString, fconc);
 newBuiltin('+', ['?',TString], TString, fconc);

diff --git a/tests/jme-runtime.js b/tests/jme-runtime.js
@@ -14301,18 +14301,29 @@ newBuiltin('+',[TList,'?'],TList, null, {
         return new TList(value);
     }
 });
-newBuiltin('+',[TDict,TDict],TDict, null,{
+
+const fn_dict_update = {
     evaluate: function(args,scope) {
         var nvalue = {};
-        Object.keys(args[0].value).forEach(function(x) {
-            nvalue[x] = args[0].value[x];
-        })
-        Object.keys(args[1].value).forEach(function(x) {
-            nvalue[x] = args[1].value[x];
-        })
+
+        if(args.length == 1 && args[0].type == 'list') {
+            args = args[0].value;
+        }
+
+        args.forEach(arg => {
+            Object.keys(arg.value).forEach(function(x) {
+                nvalue[x] = arg.value[x];
+            });
+        });
+
         return new TDict(nvalue);
     }
-});
+}
+newBuiltin('+',[TDict,TDict],TDict, null, fn_dict_update);
+
+newBuiltin('merge',['*dict'],TDict, null, fn_dict_update);
+newBuiltin('merge',['list of dict'],TDict, null, fn_dict_update);
+
 var fconc = function(a,b) { return a+b; }
 newBuiltin('+', [TString,'?'], TString, fconc);
 newBuiltin('+', ['?',TString], TString, fconc);

diff --git a/tests/jme/doc-tests.mjs b/tests/jme/doc-tests.mjs
@@ -4592,6 +4592,40 @@ export default
                         "out": "[ [\"a\",1], [\"b\",2], [\"c\",1] ]"
                     }
                 ]
+            },
+            {
+                "name": "merge",
+                "keywords": [
+                    "dictionary",
+                    "union",
+                    "update"
+                ],
+                "noexamples": false,
+                "calling_patterns": [
+                    "merge(dict1, dict2, ..., dictN)"
+                ],
+                "examples": [
+                    {
+                        "in": "merge([\"a\": 1, \"b\": 1], [\"b\": 2, \"c\": 2])",
+                        "out": "[\"a\": 1, \"b\": 2, \"c\": 2]"
+                    },
+                    {
+                        "in": "merge([\"a\": 1], [\"b\": 2], [\"c\": 3])",
+                        "out": "[\"a\": 1, \"b\": 2, \"c\": 3]"
+                    },
+                    {
+                        "in": "merge([ [\"a\": 1], [\"b\": 2] ])",
+                        "out": "[\"a\": 1, \"b\": 2]"
+                    },
+                    {
+                        "in": "merge()",
+                        "out": "dict()"
+                    },
+                    {
+                        "in": "merge([])",
+                        "out": "dict()"
+                    }
+                ]
             }
         ]
     },

diff --git a/tests/numbas-runtime.js b/tests/numbas-runtime.js
@@ -13892,18 +13892,29 @@ newBuiltin('+',[TList,'?'],TList, null, {
         return new TList(value);
     }
 });
-newBuiltin('+',[TDict,TDict],TDict, null,{
+
+const fn_dict_update = {
     evaluate: function(args,scope) {
         var nvalue = {};
-        Object.keys(args[0].value).forEach(function(x) {
-            nvalue[x] = args[0].value[x];
-        })
-        Object.keys(args[1].value).forEach(function(x) {
-            nvalue[x] = args[1].value[x];
-        })
+
+        if(args.length == 1 && args[0].type == 'list') {
+            args = args[0].value;
+        }
+
+        args.forEach(arg => {
+            Object.keys(arg.value).forEach(function(x) {
+                nvalue[x] = arg.value[x];
+            });
+        });
+
         return new TDict(nvalue);
     }
-});
+}
+newBuiltin('+',[TDict,TDict],TDict, null, fn_dict_update);
+
+newBuiltin('merge',['*dict'],TDict, null, fn_dict_update);
+newBuiltin('merge',['list of dict'],TDict, null, fn_dict_update);
+
 var fconc = function(a,b) { return a+b; }
 newBuiltin('+', [TString,'?'], TString, fconc);
 newBuiltin('+', ['?',TString], TString, fconc);