Add a new seed_type, let-multi.

Like let, but it allows setting multiple values at once.

Part of #18. Part of #36.

README.md

@@ -411,6 +411,7 @@ Array is useful when you want to execute multiple statements in sequence, for ex
 
 Required parameters:
 - `items` - An array of values. The values may be LeafValue or a SeedReference / SubSeed.
+- `return` (optional, default: 'all') - One of {'all', 'first', 'last'}. If all, will return the full array of values. If 'first', will return the single first result, or null if there are no items. If 'last' will return the first result, or null if there are no items.
 
 #### var
 
@@ -421,7 +422,7 @@ Required parameters:
 
 #### let
 
-Sets a named variable in environment to value for sub-expressions in block. It returns the return value of block. See also `var`.
+Sets a named variable in environment to value for sub-expressions in block. It returns the return value of block. See also `var` and `let-multi`.
 
 A value that persists is available with seed_type `store`.
 
@@ -432,6 +433,18 @@ Required parameters:
 - `value` - The value to set the variable to.
 - `block` - The sub-seed that will be evaluated where the environment will have `name=value`.
 
+#### let-multi
+
+Sets multiple names to variables in environment to value for sub-expressions in block. It returns the return value of block. See also `var` and `let`.
+
+A value that persists is available with seed_type `store`.
+
+Note that this doesn't change the environment globally, but only for the context of calculating the seeds nested beneath `block`.
+
+Required parameters:
+- `values` - The object of name -> value pairs to set.
+- `block` - The sub-seed that will be evaluated where the environment will have `name=value`.
+
 #### store
 
 Stores a value in the long-term key/val store.

seed-schema.json

@@ -1432,6 +1432,82 @@
 					],
 					"additionalProperties": false
 				},
+				{
+					"type": "object",
+					"properties": {
+						"id": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/id"
+						},
+						"description": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/description"
+						},
+						"type": {
+							"type": "string",
+							"const": "let-multi"
+						},
+						"values": {
+							"anyOf": [
+								{
+									"$ref": "#/definitions/seedData"
+								},
+								{
+									"$ref": "#/definitions/seedData/anyOf/0/properties/prompt/anyOf/1"
+								},
+								{
+									"type": "object",
+									"additionalProperties": {
+										"anyOf": [
+											{
+												"type": "null"
+											},
+											{
+												"type": "number"
+											},
+											{
+												"type": "string"
+											},
+											{
+												"type": "boolean"
+											},
+											{}
+										]
+									},
+									"propertyNames": {
+										"pattern": "^(?!type$)[a-zA-Z0-9_-]+$"
+									},
+									"description": "The map of name -> variables to set"
+								}
+							]
+						},
+						"block": {
+							"anyOf": [
+								{
+									"$ref": "#/definitions/seedData"
+								},
+								{
+									"$ref": "#/definitions/seedData/anyOf/0/properties/prompt/anyOf/1"
+								},
+								{
+									"anyOf": [
+										{
+											"$ref": "#/definitions/seedData/anyOf/5/properties/value/anyOf/2/anyOf/0"
+										},
+										{
+											"$ref": "#/definitions/seedData/anyOf/5/properties/value/anyOf/2/anyOf/1"
+										}
+									],
+									"description": "The sub-expression where name=value will be set in environment"
+								}
+							]
+						}
+					},
+					"required": [
+						"type",
+						"values",
+						"block"
+					],
+					"additionalProperties": false
+				},
 				{
 					"type": "object",
 					"properties": {

src/grow.ts

@@ -37,7 +37,9 @@ import {
 	inputValue,
 	SeedDataRetrieve,
 	SeedDataDelete,
-	arrayReturnType
+	arrayReturnType,
+	SeedDataLetMulti,
+	EnvironmentData
 } from './types.js';
 
 import {
@@ -493,6 +495,22 @@ const growLet = async (seed : Seed<SeedDataLet>, env : Environment) : Promise<Va
 	return await getProperty(seed, newEnv, data.block);
 };
 
+const growLetMulti = async (seed : Seed<SeedDataLetMulti>, env : Environment) : Promise<Value> => {
+	const data = seed.data;
+
+	const values = await getProperty(seed, env, data.values);
+	if (typeof values != 'object') throw new Error('Values must be an object');
+	if (Array.isArray(values)) throw new Error('Values must be an object');
+	if (!values) throw new Error('Values must be an object');
+	const vars : EnvironmentData = {};
+	for (const [key, val] of Object.entries(values)) {
+		if (knownEnvironmentSecretKey.safeParse(key).success) throw new Error(`let may not set secret keys: ${key}`);
+		vars[key] = val;
+	}
+	const newEnv = env.clone(vars);
+	return await getProperty(seed, newEnv, data.block);
+};
+
 const growStore = async (seed : Seed<SeedDataStore>, env : Environment) : Promise<Value> => {
 	const data = seed.data;
 	const storeID = extractString(await getProperty(seed, env, data.store, env.getKnownStringKey('store')));
@@ -598,6 +616,9 @@ export const grow = async (seed : Seed, env : Environment) : Promise<Value> => {
 	case 'let':
 		result = await growLet(seed as Seed<SeedDataLet>, env);
 		break;
+	case 'let-multi':
+		result = await growLetMulti(seed as Seed<SeedDataLetMulti>, env);
+		break;
 	case 'store':
 		result = await growStore(seed as Seed<SeedDataStore>, env);
 		break;

src/types.ts

@@ -630,6 +630,19 @@ const seedDataLet = makeSeedData(seedDataConfigLet);
 
 export type SeedDataLet = z.infer<typeof seedDataLet>;
 
+const seedDataConfigLetMulti = {
+	type: z.literal('let-multi'),
+	properties: {
+		values: valueObject.describe('The map of name -> variables to set'),
+		block: inputNonObjectValue.describe('The sub-expression where name=value will be set in environment')
+	}
+};
+
+const nestedSeedDataLetMulti = makeNestedSeedData(seedDataConfigLetMulti);
+const seedDataLetMulti = makeSeedData(seedDataConfigLetMulti);
+
+export type SeedDataLetMulti = z.infer<typeof seedDataLetMulti>;
+
 const seedDataConfigStore = {
 	type: z.literal('store'),
 	properties: {
@@ -700,6 +713,7 @@ export const expandedSeedData = z.discriminatedUnion('type', [
 	seedDataArray,
 	seedDataVar,
 	seedDataLet,
+	seedDataLetMulti,
 	seedDataStore,
 	seedDataRetrieve,
 	seedDataDelete
@@ -731,6 +745,7 @@ export const seedData = z.discriminatedUnion('type', [
 	nestedSeedDataArray,
 	nestedSeedDataVar,
 	nestedSeedDataLet,
+	nestedSeedDataLetMulti,
 	nestedSeedDataStore,
 	nestedSeedDataRetrieve,
 	nestedSeedDataDelete

test/base/a_test.json

@@ -109,6 +109,30 @@
                 }
             }
         },
+        "let-multi-test": {
+            "type": "let-multi",
+            "values": {
+                "name": "Alex",
+                "foo": 3
+            },
+            "block": {
+                "type": "render",
+                "template": "{{age}} is {{name}}",
+                "vars": {
+                    "type": "object",
+                    "properties": {
+                        "age": {
+                            "type": "var",
+                            "name": "foo"
+                        },
+                        "name": {
+                            "type": "var",
+                            "name": "name"
+                        }
+                    }
+                }
+            }
+        },
         "let-test-secret-key": {
             "type": "let",
             "name": "openai_secret_key",

test/base/test.ts

@@ -395,6 +395,14 @@ describe('Garden smoke test', () => {
 		assert.deepStrictEqual(result, golden);
 	});
 
+	it ('testing let-multi seed', async () => {
+		const garden = loadTestGarden();
+		const seed = await garden.seed('let-multi-test');
+		const result = await seed.grow();
+		const golden = '3 is Alex';
+		assert.deepStrictEqual(result, golden);
+	});
+
 	it ('testing let seed with secret key fails', async () => {
 		const garden = loadTestGarden();
 		const seed = await garden.seed('let-test-secret-key');