Add CSV file reading functionality to the workspace file system (#740)

* Fix typo in CLI usage and add readCSV method to WorkspaceFileSystem interface

* Add CSV file reading functionality to the workspace file system

* Enhance readCSV function with generic type support and optional parsing options

docs/src/content/docs/reference/cli/commands.md

@@ -235,9 +235,9 @@ Options:
 
 ## `retrieval`
 
+```
 Usage: genaiscript retrieval|retreival [options] [command]
 
-RAG support
 RAG support
 
 Options:

docs/src/content/docs/reference/scripts/files.md

@@ -87,6 +87,22 @@ Reads the content of a file as XML.
 const data = await workspace.readXML("data.xml")
 ```
 
+### `readCSV`
+
+Reads the content of a file as CSV.
+
+```ts
+const data = await workspace.readCSV("data.csv")
+```
+
+In Typescript, you can type the output.
+
+```ts '<{ name: string; value: number }>'
+const data = await workspace.readCSV<{ name: string; value: number }>(
+    "data.csv"
+)
+```
+
 ### `writeText`
 
 Writes text to a file, relative to the workspace root.

packages/core/src/filesystem.ts

@@ -1,5 +1,6 @@
 import { JSONLineCache } from "./cache"
 import { DOT_ENV_REGEX } from "./constants"
+import { CSVParse } from "./csv"
 import { NotSupportedError, errorMessage } from "./error"
 import { resolveFileContent } from "./file"
 import { readText, writeText } from "./fs"
@@ -68,6 +69,14 @@ export function createFileSystem(): Omit<WorkspaceFileSystem, "grep"> {
             const res = XMLParse(file.content)
             return res
         },
+        readCSV: async <T extends object>(
+            f: string | Awaitable<WorkspaceFile>,
+            options?: CSVParseOptions
+        ): Promise<T[]> => {
+            const file = await fs.readText(f)
+            const res = CSVParse(file.content, options) as T[]
+            return res
+        },
         cache: async (name: string) => {
             if (!name) throw new NotSupportedError("missing cache name")
             const res = JSONLineCache.byName<any, any>(name)

packages/core/src/promptcontext.ts

@@ -64,6 +64,7 @@ export async function createPromptContext(
         readText: (f) => runtimeHost.workspace.readText(f),
         readJSON: (f) => runtimeHost.workspace.readJSON(f),
         readXML: (f) => runtimeHost.workspace.readXML(f),
+        readCSV: (f) => runtimeHost.workspace.readCSV(f),
         writeText: (f, c) => runtimeHost.workspace.writeText(f, c),
         cache: (n) => runtimeHost.workspace.cache(n),
         findFiles: async (pattern, options) => {

packages/core/src/types/prompt_template.d.ts

@@ -579,6 +579,15 @@ interface WorkspaceFileSystem {
      */
     readXML(path: string | Awaitable<WorkspaceFile>): Promise<any>
 
+    /**
+     * Reads the content of a CSV file.
+     * @param path
+     */
+    readCSV<T extends object>(
+        path: string | Awaitable<WorkspaceFile>,
+        options?: CSVParseOptions
+    ): Promise<T[]>
+
     /**
      * Writes a file as text to the file system
      * @param path
@@ -969,6 +978,11 @@ interface ParseZipOptions {
 
 type TokenEncoder = (text: string) => number[]
 
+interface CSVParseOptions {
+    delimiter?: string
+    headers?: string[]
+}
+
 interface Parsers {
     /**
      * Parses text as a JSON5 payload
@@ -1034,7 +1048,7 @@ interface Parsers {
      */
     CSV(
         content: string | WorkspaceFile,
-        options?: { delimiter?: string; headers?: string[] }
+        options?: CSVParseOptions
     ): object[] | undefined
 
     /**