feat: add support for SQL syntax highlighting

assets/highlighting-tests/sql.sql

@@ -0,0 +1,305 @@
+-- Single-line comment
+
+/*
+ * Multi-line comment.
+ * The comment should remain highlighted across lines.
+ */
+
+-- Basic SELECT
+SELECT
+    id,
+    name,
+    email
+FROM
+    users
+WHERE
+    active = TRUE;
+
+-- Aliases and expressions
+SELECT
+    u.id AS user_id,
+    u.name AS user_name,
+    u.age + 1 AS next_age
+FROM
+    users AS u
+WHERE
+    u.age >= 18
+    AND u.name IS NOT NULL;
+
+-- String literals
+SELECT
+    'hello',
+    'It''s a string',
+    'single quotes are escaped by doubling them';
+
+-- Quoted identifiers
+SELECT
+    "user",
+    "first""name"
+FROM
+    "users";
+
+-- Backtick-quoted identifiers
+SELECT
+    `user`,
+    `first``name`
+FROM
+    `users`;
+
+-- Numeric literals
+SELECT
+    0,
+    42,
+    -17,
+    3.14159,
+    1.5e -3;
+
+-- Boolean and NULL literals
+SELECT
+    TRUE,
+    FALSE,
+    NULL;
+
+-- Comparison and logical operators
+SELECT
+    *
+FROM
+    users
+WHERE
+    age >= 18
+    AND age <= 65
+    AND status != 'inactive'
+    AND name <> 'Unknown'
+    AND (
+        active = TRUE
+        OR verified = FALSE
+    );
+
+-- LIKE, IN and BETWEEN
+SELECT
+    *
+FROM
+    users
+WHERE
+    name LIKE 'A%'
+    AND age BETWEEN 18
+    AND 30
+    AND status IN ('active', 'pending');
+
+-- INSERT
+INSERT INTO
+    users (name, email, age)
+VALUES
+    ('Alice', 'alice@example.com', 25);
+
+-- Multiple-row INSERT
+INSERT INTO
+    users (name, email)
+VALUES
+    ('Bob', 'bob@example.com'),
+    ('Carol', 'carol@example.com');
+
+-- UPDATE
+UPDATE
+    users
+SET
+    name = 'Updated',
+    active = FALSE
+WHERE
+    id = 42;
+
+-- DELETE
+DELETE FROM
+    users
+WHERE
+    active = FALSE;
+
+-- JOINs
+SELECT
+    u.name,
+    o.id,
+    o.total
+FROM
+    users AS u
+    INNER JOIN orders AS o ON o.user_id = u.id
+    LEFT JOIN payments AS p ON p.order_id = o.id
+WHERE
+    o.total > 100;
+
+-- GROUP BY and aggregate functions
+SELECT
+    department,
+    COUNT(*) AS employee_count,
+    SUM(salary) AS total_salary,
+    AVG(salary) AS average_salary,
+    MIN(salary) AS minimum_salary,
+    MAX(salary) AS maximum_salary
+FROM
+    employees
+GROUP BY
+    department
+HAVING
+    COUNT(*) > 5
+ORDER BY
+    average_salary DESC;
+
+-- DISTINCT, LIMIT and OFFSET
+SELECT
+    DISTINCT name
+FROM
+    users
+ORDER BY
+    name ASC
+LIMIT
+    10 OFFSET 20;
+
+-- CASE expression
+SELECT
+    name,
+    CASE
+        WHEN age < 18 THEN 'minor'
+        WHEN age >= 18
+        AND age < 65 THEN 'adult'
+        ELSE 'senior'
+    END AS age_group
+FROM
+    users;
+
+-- Common functions
+SELECT
+    LOWER(name),
+    UPPER(name),
+    LENGTH(name),
+    SUBSTRING(name, 1, 5),
+    ROUND(balance),
+    ABS(balance),
+    COALESCE(nickname, name),
+    NULLIF(status, '');
+
+-- CAST and conversion
+SELECT
+    CAST(age AS INTEGER),
+    CONVERT(name, VARCHAR(100))
+FROM
+    users;
+
+-- Common DDL
+CREATE TABLE users (
+    id INTEGER PRIMARY KEY,
+    name VARCHAR(100) NOT NULL,
+    email VARCHAR(255) UNIQUE,
+    age INTEGER DEFAULT 0,
+    active BOOLEAN DEFAULT TRUE
+);
+
+-- Constraints
+CREATE TABLE orders (
+    id INTEGER PRIMARY KEY,
+    user_id INTEGER NOT NULL,
+    total DECIMAL(10, 2) CHECK (total >= 0),
+    CONSTRAINT fk_user FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- Index
+CREATE INDEX idx_users_email ON users (email);
+
+-- View
+CREATE VIEW active_users AS
+SELECT
+    id,
+    name,
+    email
+FROM
+    users
+WHERE
+    active = TRUE;
+
+-- ALTER and DROP
+ALTER TABLE
+    users
+ADD
+    COLUMN created_at TIMESTAMP;
+
+DROP VIEW active_users;
+
+-- Common transaction keywords
+BEGIN;
+
+UPDATE
+    users
+SET
+    active = TRUE
+WHERE
+    id = 1;
+
+COMMIT;
+
+BEGIN;
+
+DELETE FROM
+    users
+WHERE
+    id = 999;
+
+ROLLBACK;
+
+-- CTE
+WITH active_users AS (
+    SELECT
+        id,
+        name
+    FROM
+        users
+    WHERE
+        active = TRUE
+)
+SELECT
+    *
+FROM
+    active_users
+ORDER BY
+    name;
+
+-- UNION
+SELECT
+    id,
+    name
+FROM
+    users
+UNION
+SELECT
+    id,
+    name
+FROM
+    archived_users;
+
+-- EXISTS
+SELECT
+    *
+FROM
+    users AS u
+WHERE
+    EXISTS (
+        SELECT
+            1
+        FROM
+            orders AS o
+        WHERE
+            o.user_id = u.id
+    );
+
+-- NULL checks
+SELECT
+    *
+FROM
+    users
+WHERE
+    email IS NULL
+    OR email IS NOT NULL;
+
+-- Function calls with nested expressions
+SELECT
+    COALESCE(LOWER(name), 'unknown'),
+    ROUND(ABS(balance), 2)
+FROM
+    accounts;

crates/lsh/definitions/markdown.lsh

@@ -50,6 +50,16 @@ pub fn markdown() {
                     if /.*/ {}
                 }
             }
+        } else if /(?i:sql)/ {
+            loop {
+                await input;
+                if /\s*```/ {
+                    return;
+                } else {
+                    sql();
+                    if /.*/ {}
+                }
+            }
         } else if /(?i:json)/ {
             loop {
                 await input;