Domain

Backend — HTTP server, databases and auth

eTamil runs backend services: an HTTP server with routing, SQLite and PostgreSQL drivers with parameterised queries only, JSON, bcrypt and JWT.

eTamil is a backend language. A program can serve HTTP, talk to a SQL database, hash passwords and issue tokens — without dropping into Rust.

The HTTP server

etamil --server --port 8080 examples/backend/hello_server.qmz
etamil --async  --port 8080 examples/backend/hello_server.qmz

--server runs a worker pool. --async runs a tokio accept loop and hands each request to the blocking pool, so a connection costs a task rather than a thread and a slow client no longer occupies one of 2 × cores workers for as long as it takes to send its request. The VM itself stays synchronous — handlers block, on tokio’s blocking pool, so every database driver keeps working untouched.

Routes

வழி declares a route; பதில் answers.

வழி பெறு, "/kaNakku/:id" {
    பதில் 200, "id=" & param_id & " vakY=" & query_params["vakY"];
}

வழி பதி, "/pativu" {
    பதில் 201, "got body: " & request_body;
}

வழி பெறு, "/aRikkY.csv" {
    பதில் 200, வரிசைகள், {"Content-Type": "text/csv"};
}

A handler reads its request through plain variables, so the same handler is readable in either spelling:

Variable	Contents
request_method	the HTTP method
request_path	the path as requested
request_body	the raw body
query_params	query string, as a record
headers	request headers, as a record
path_params	matched :name segments, as a record
param_<name>	each path parameter, also bound directly

Response headers are an ordinary record. Without one, the server answers application/json.

Flag	Effect
--vm	Run on the bytecode VM (default)
--server	Start the synchronous HTTP server
--async	Concurrent server: async accept, blocking handlers, Ctrl-C to stop
--llvm	LLVM backend (requires --features llvm; Linux/macOS)
--port <PORT>	Server port (default 8080)
--host <HOST>	Server host (default 127.0.0.1)

Databases

Queries are always parameterised. There is deliberately no way to splice a value into SQL text from eTamil, so the injection class of bug is not available to write.

தளம்_இணை எசுகியூஎல்லைட், "kaNakku.db";
தளம்_வினா "SELECT peyar, qokY FROM pativukaL WHERE vakY = ?", ["வரவு"], வரவுகள்;

Rows return as an array of records, so a result set iterates like any other table.

Engine	Status	Notes
SQLite	Working	Built in, no feature flag. Decimals cross as text, so no precision is lost
PostgreSQL	Working	--features postgres; verified against a live server. Money uses native NUMERIC
MySQL / MariaDB	Untested	--features mysql; complete and compiling, never run against a live server
MongoDB, Redis	Not implemented	Neither has SQL, so neither fits an execute(sql, params) trait. Needs a design first

cargo build --release --features postgres,mysql

PostgreSQL placeholders are $1, $2, …; SQLite and MySQL use ?.

தளம்_இணை போச்குரசீகுல், "postgres://user:pass@localhost:5432/kaNakku";
தளம்_வினா "SELECT peyar, qokY FROM pativukaL WHERE vakY = $1", ["வரவு"], வரவுகள்;

Both server backends keep money in the database’s own exact decimal type, so a text column stays text on the way back — where the SQLite backend, which stores decimals as text, hands back a number. PostgreSQL also folds unquoted identifiers to lower case: write "qokY" if you want that column name back as you spelled it.

Still to do. Transactions, and more than one connection open at a time — the VM currently refuses the second rather than guessing which one you meant.

JSON

jEcAZ.qmz is written in eTamil, not in the host. A JSON parser needs to build a record whose field names come from the data, and the VM already allows that: பொருள்[சாவி] = மதிப்பு computes the key at runtime.

இறக்கு "nUlakam/jEcAZ.qmz";

ப = மதிப்பு(ஜேசான்_படி(request_body));
அச்சு ப["qokY"] + 1;                       // a number, not text
பதில் 200, ஜேசான்_ஆக்கு({நிலுவை: 1500});

ஜேசான்_படி returns சரி/தவறு, so malformed input is handled rather than guessed at. Record fields serialize in sorted order, which makes a response body stable enough to assert on. \uXXXX escapes are not decoded.

ஜேசான்_உரை is not implemented. It parses, but the VM refuses it. Build the body with ஜேசான்_ஆக்கு and send it with பதில்.

Authentication

bcrypt and JWT live in the host, because hashing and HMAC-SHA256 need bytes and randomness the language cannot reach:

கடவுச்சொல்_மறை · கடவுச்சொல்_சரியா · சீட்டு_ஆக்கு · சீட்டு_சரிபார்

Set ETAMIL_JWT_SECRET before starting the server. Everything above these four — who a user is, which route needs which role — stays in eTamil, and a token’s payload crosses the boundary as JSON text that jEcAZ.qmz reads and writes.

Examples

etamil --server --port 8080 examples/backend/hello_server.qmz
etamil --server --port 8080 examples/backend/user_server.qmz
etamil --server --port 8080 examples/api/vari_cEvY.qmz
etamil --vm examples/db_samples/kaNakku_qaLam.qmz

examples/db_samples/mYcIkul_qaLam.qmz checks what is worth checking on a real MySQL server — exact DECIMAL sums, an integer key bound from a number, dates as ISO text, NULL as இன்மை, and an injection payload staying inert. It needs a live database, so the example runner skips it unless you opt in:

ETAMIL_TEST_MYSQL=1 ./scripts/run_examples.sh