How to use @taggedTemplate generate js with tagged template literals

1

I am using Rescript v11 to bind the Postgress.js API. Since returned by the “make” binding is a tagged Template function , I cannot use @taggedTemplate to descript it. The generated js file is not with tagged Template. How can I use @taggedTemplate so that gen the js code with tagged Template ?

[GitHub - porsager/postgres: Postgres.js]
(GitHub - porsager/postgres: Postgres.js - The Fastest full featured PostgreSQL client for Node.js, Deno, Bun and CloudFlare)

bind

type t<'sqlParam, 'data> = (array<string>, array<'sqlParam>) => promise<result<'data>>
@module("postgres") external make: (~url: string, ~config: config=?) => t<'sqlParam, 'data> = "default"

usage

let sql = Postgresql.make(~url="postgres://xxx:xxxx@localhost:5432/xxxxxx")
let abc = "abc"
let result: Postgresql.result<userInfo> = await sql`select name, sigup_date from user_tbl where name=${ abc }`

output:

var result = await sql([
              "select name, sigup_date from user_tbl where name=",
              ""
            ], ["abc"]);
2

Hi @liang, sorry for the late reply but there’s no easy way to do this today, we should support such tags (like @taggedTemplate or @variadic) in function parameters which we don’t today. It was too much of a pain originally, but I’ll take a look at it now that v12 is uncurried only and has a cleaner AST.

1 Like
3

@tsnobip Thank for you reply, I’m trying to solve this problem with other way these days, but it doesn’t work well

First I patch the code (compile to PostgresqlPatch.js)

%%raw(`
import Postgres from "postgres"

export default myPostgres;

function myPostgres(a, b) {

    var sql = Postgres(a, b);
    Object.assign(sql, {safeSql: sql})
    return sql;
}

`)

Then bind the path code use the object function

type t
@module("./PostgresqlPatch.js") external make: (~url: string, ~config: config=?) => t = "default"

@taggedTemplate @send
external safeSql: (t, array<string>, array<'sqlParam>) => promise<result<'data>> = "safeSql"

Then call object function:

let abc = "name"
    let result: Postgresql.result<userInfo> = await sql->Postgresql.safeSql`select name, sigup_date from user_tbl where name=${ abc }`

output:

var result = await sql.safeSql([
              "select name, sigup_date from user_tbl where name=",
              ""
            ], "name");

Is it possible to consider ways to support object functions in the future?
Thanks.

4

what do you mean by object functions?

In the meanwhile, the easiest solution by far is just to initialize your sql function in raw js and bind to it:

%%raw(`import Postgres from "postgres"
let sql = Postgres("postgres://xxx:xxxx@localhost:5432/xxxxxx")`)
@taggedTemplate
external sql: (array<string>, array<'sqlParam>) => promise<'data> = "sql"

let foo = sql`hello`

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