feat(parser): extend Parser with parseTablePrimaryKey

src/main/kotlin/kestrel/sql/parser/Parser.kt

@@ -420,18 +420,58 @@ class Parser(private val tokens: List<Token>) {
         return CreateTableStatement(tableName, columns, foreignKeys, checks, uniqueConstraints, compositePrimaryKey, temporary)
     }
 
-    private fun parseColumnDefinition(): Column {
-        val columnName = expectIdentifier("expected column name")
-        val typeToken = advance()
-        val type = when (typeToken.type) {
-            TokenType.Integer -> ColumnType.Integer
-            TokenType.Text -> ColumnType.Text
-            TokenType.Boolean -> ColumnType.Boolean
-            TokenType.Real -> ColumnType.Real
-            else -> throw error("expected a column type but found '${describe(typeToken)}'", typeToken)
+    private fun parseTablePrimaryKey(): List<String> {
+        expect(TokenType.Primary, "expected PRIMARY")
+        expect(TokenType.Key, "expected KEY after PRIMARY")
+        expect(TokenType.LeftParen, "expected '(' after PRIMARY KEY")
+        val columns = mutableListOf<String>()
+        do {
+            columns.add(expectIdentifier("expected column name"))
+        } while (match(TokenType.Comma))
+        expect(TokenType.RightParen, "expected ')' after PRIMARY KEY column list")
+        return columns
+    }
+
+    /**
+     * `CONSTRAINT name FOREIGN KEY (...) | CHECK (...) | UNIQUE (...)` - a named table-level
+     * constraint, standard SQL syntax this engine accepts both inline in `CREATE TABLE` (here) and
+     * via `ALTER TABLE ... ADD` (see [parseAlterTable]'s identical dispatch). `PRIMARY KEY` is
+     * deliberately not accepted after `CONSTRAINT name`: [kestrel.catalog.TableSchema] has no name
+     * field for a table's PRIMARY KEY at all, so there would be nowhere to put it, and
+     * `ALTER TABLE ... DROP CONSTRAINT` never needs to target a PRIMARY KEY (see
+     * [kestrel.catalog.Catalog.dropColumn]'s own doc on why dropping a PRIMARY KEY is out of scope
+     * entirely - redesign it or drop the table instead).
+     */
+    private fun parseNamedTableConstraint(
+        foreignKeys: MutableList<ForeignKeyConstraint>,
+        checks: MutableList<CheckConstraint>,
+        uniqueConstraints: MutableList<UniqueConstraint>
+    ) {
+        advance()
+        val name = expectIdentifier("expected constraint name after CONSTRAINT")
+        when {
+            check(TokenType.Foreign) -> foreignKeys.add(parseTableForeignKey().copy(name = name))
+            check(TokenType.Check) -> checks.add(parseTableCheck().copy(name = name))
+            check(TokenType.Unique) -> uniqueConstraints.add(parseTableUnique().copy(name = name))
+            else -> throw error(
+                "expected FOREIGN KEY, CHECK, or UNIQUE after CONSTRAINT $name but found '${describe(peek())}'",
+                peek()
+            )
         }
+    }
+
+    private fun parseColumnDefinition(
+        foreignKeys: MutableList<ForeignKeyConstraint>,
+        checks: MutableList<CheckConstraint>,
+        uniqueConstraints: MutableList<UniqueConstraint>
+    ): Column {
+        val columnName = expectIdentifier("expected column name")
+        val spec = parseTypeSpec()
         var notNull = false
         var primaryKey = false
+        var default: Expression? = null
+        var generated: Expression? = null
+        var collation = Collation.Binary
         while (true) {
             when {
                 check(TokenType.Not) -> {
@@ -445,6 +485,18 @@ class Parser(private val tokens: List<Token>) {
                     primaryKey = true
                     notNull = true
                 }
+                check(TokenType.Unique) -> {
+                    advance()
+                    uniqueConstraints.add(UniqueConstraint(null, listOf(columnName)))
+                }
+                check(TokenType.References) -> foreignKeys.add(parseInlineForeignKey(columnName))
+                check(TokenType.Check) -> checks.add(parseColumnCheck())
+                check(TokenType.Default) -> {
+                    advance()
+                    default = parseExpression()
+                }
+                isContextualKeyword("GENERATED") -> generated = parseGeneratedClause()
+                check(TokenType.Collate) -> collation = parseColumnCollation()
                 else -> break
             }
         }