Add a slice seed_type.

Part of #46.

README.md

@@ -600,6 +600,15 @@ Required parameters
 - `container` - The string, object, or array to search within.
 - `search` - The thing to find within the container.
 
+#### slice
+
+Returns a new subset of the input.
+
+Required parameters
+- `input` - The string or array to create a slice of.
+- `start` - (optional) The start index. If omitted, defaults to 0. May be negative to count from end of item.
+- `end` - (optional) The first index to not include. May be negative to count from end of item. If omitted, defaults to `input.length`.
+
 #### split
 
 Splits a string at a delimiter to give an array of strings.

seed-schema.json

@@ -2454,6 +2454,95 @@
 					],
 					"additionalProperties": false
 				},
+				{
+					"type": "object",
+					"properties": {
+						"id": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/id"
+						},
+						"description": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/description"
+						},
+						"comment": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/comment"
+						},
+						"private": {
+							"$ref": "#/definitions/seedData/anyOf/0/properties/private"
+						},
+						"type": {
+							"type": "string",
+							"const": "slice"
+						},
+						"input": {
+							"anyOf": [
+								{
+									"$ref": "#/definitions/seedData"
+								},
+								{
+									"$ref": "#/definitions/seedData/anyOf/0/properties/prompt/anyOf/1"
+								},
+								{
+									"anyOf": [
+										{
+											"type": "string"
+										},
+										{
+											"$ref": "#/definitions/seedData/anyOf/5/properties/value/anyOf/2/anyOf/1/additionalProperties/anyOf/2/anyOf/2"
+										}
+									],
+									"description": "The thing to slice"
+								}
+							]
+						},
+						"start": {
+							"anyOf": [
+								{
+									"$ref": "#/definitions/seedData"
+								},
+								{
+									"$ref": "#/definitions/seedData/anyOf/0/properties/prompt/anyOf/1"
+								},
+								{
+									"anyOf": [
+										{
+											"not": {}
+										},
+										{
+											"type": "integer"
+										}
+									],
+									"description": "The index to start from"
+								}
+							]
+						},
+						"end": {
+							"anyOf": [
+								{
+									"$ref": "#/definitions/seedData"
+								},
+								{
+									"$ref": "#/definitions/seedData/anyOf/0/properties/prompt/anyOf/1"
+								},
+								{
+									"anyOf": [
+										{
+											"not": {}
+										},
+										{
+											"type": "integer"
+										}
+									],
+									"description": "The index to end before (exclusive)"
+								}
+							]
+						}
+					},
+					"required": [
+						"type",
+						"input"
+					],
+					"additionalProperties": false
+				},
 				{
 					"type": "object",
 					"properties": {
@@ -2917,7 +3006,7 @@
 								{
 									"anyOf": [
 										{
-											"$ref": "#/definitions/seedData/anyOf/36/properties/name/anyOf/2/anyOf/0"
+											"$ref": "#/definitions/seedData/anyOf/37/properties/name/anyOf/2/anyOf/0"
 										},
 										{
 											"$ref": "#/definitions/seedData/anyOf/2/properties/memory/anyOf/2/anyOf/1"
@@ -3186,7 +3275,7 @@
 								{
 									"type": "object",
 									"additionalProperties": {
-										"$ref": "#/definitions/seedData/anyOf/41/properties/defaults/anyOf/2/anyOf/1/additionalProperties"
+										"$ref": "#/definitions/seedData/anyOf/42/properties/defaults/anyOf/2/anyOf/1/additionalProperties"
 									},
 									"propertyNames": {
 										"pattern": "^arg:[a-zA-Z0-9-_.]*$"

src/grow.ts

@@ -61,7 +61,8 @@ import {
 	SeedDataEnumerate,
 	enumerateResourceType,
 	SeedDataSpread,
-	SeedDataIndex
+	SeedDataIndex,
+	SeedDataSlice
 } from './types.js';
 
 import {
@@ -647,6 +648,21 @@ const growIndex = async (seed : Seed<SeedDataIndex>, env : Environment) : Promis
 	return result < 0 ? null : result;
 };
 
+const growSlice = async (seed : Seed<SeedDataSlice>, env : Environment) : Promise<ValueArray | string> => {
+	const data = seed.data;
+	let input = await getProperty(seed, env, data.input, null);
+	if (input === null) throw new Error('input is a required property');
+	if (input instanceof Embedding) input = input.text;
+	if (!Array.isArray(input) && typeof input != 'string') throw new Error('input must be a string or array');
+
+	const start = await getProperty(seed, env, data.start, 0);
+	if (typeof start != 'number') throw new Error('start must be a number');
+	const end = await getProperty(seed, env, data.end, Number.MAX_SAFE_INTEGER);
+	if (typeof end != 'number') throw new Error('end must be a number');
+
+	return input.slice(start, end);
+};
+
 const growSplit = async (seed : Seed<SeedDataSplit>, env : Environment) : Promise<ValueArray> => {
 	const data = seed.data;
 	const input = extractString(await getProperty(seed, env, data.input, null));
@@ -952,6 +968,9 @@ export const grow = async (seed : Seed, env : Environment) : Promise<Value> => {
 	case 'index':
 		result = await growIndex(seed as Seed<SeedDataIndex>, env);
 		break;
+	case 'slice':
+		result = await growSlice(seed as Seed<SeedDataSlice>, env);
+		break;
 	case 'split':
 		result = await growSplit(seed as Seed<SeedDataSplit>, env);
 		break;

src/types.ts

@@ -855,6 +855,20 @@ const seedDataIndex = makeSeedData(seedDataConfigIndex);
 
 export type SeedDataIndex = z.infer<typeof seedDataIndex>;
 
+const seedDataConfigSlice = {
+	type: z.literal('slice'),
+	properties: {
+		input: z.union([z.string(), inputValueArray]).describe('The thing to slice'),
+		start: z.number().int().optional().describe('The index to start from'),
+		end: z.number().int().optional().describe('The index to end before (exclusive)')
+	}
+};
+
+const nestedSeedDataSlice = makeNestedSeedData(seedDataConfigSlice);
+const seedDataSlice = makeSeedData(seedDataConfigSlice);
+
+export type SeedDataSlice = z.infer<typeof seedDataSlice>;
+
 const seedDataConfigSplit = {
 	type: z.literal('split'),
 	properties: {
@@ -1112,6 +1126,7 @@ export const expandedSeedData = z.discriminatedUnion('type', [
 	seedDataFilter,
 	seedDataSpread,
 	seedDataIndex,
+	seedDataSlice,
 	seedDataSplit,
 	seedDataJoin,
 	seedDataThrow,
@@ -1164,6 +1179,7 @@ export const seedData = z.discriminatedUnion('type', [
 	nestedSeedDataFilter,
 	nestedSeedDataSpread,
 	nestedSeedDataIndex,
+	nestedSeedDataSlice,
 	nestedSeedDataSplit,
 	nestedSeedDataJoin,
 	nestedSeedDataThrow,

test/base/a_test.json

@@ -475,6 +475,20 @@
                 2
             ],
             "search": 1
+        },
+        "slice-string-test": {
+            "type": "slice",
+            "input": "012345"
+        },
+        "slice-array-test": {
+            "type": "slice",
+            "input": [
+                0,
+                1,
+                2,
+                3
+            ],
+            "end": -1
         }
     }
 }

test/base/test.ts

@@ -1028,6 +1028,22 @@ Suffix`;
 		assert.deepStrictEqual(actual, golden);
 	});
 
+	it('slice string', async () => {
+		const garden = loadTestGarden();
+		const seed = await garden.seed('slice-string-test');
+		const actual = await seed.grow();
+		const golden = '012345';
+		assert.deepStrictEqual(actual, golden);
+	});
+
+	it('slice array', async () => {
+		const garden = loadTestGarden();
+		const seed = await garden.seed('slice-array-test');
+		const actual = await seed.grow();
+		const golden = [0, 1, 2];
+		assert.deepStrictEqual(actual, golden);
+	});
+
 });
 
 describe('expandSeedPacket tests', () => {