Scan AND and OR

src/lexer.ts

@@ -43,6 +43,12 @@ export default class Lexer {
     } else if (source.match(/^as/i)) {
       this.advance(2);
       return new Token(TokenKind.AS, null, this.line);
+    } else if (source.match(/^and/i)) {
+      this.advance(3);
+      return new Token(TokenKind.AND, null, this.line);
+    } else if (source.match(/^or/i)) {
+      this.advance(2);
+      return new Token(TokenKind.OR, null, this.line);
     } else if (source.match(/^\+/)) {
       this.advance();
       return new Token(TokenKind.PLUS, null, this.line);

src/token.ts

@@ -1,4 +1,5 @@
 export enum TokenKind {
+  AND = "AND",
   AS = "AS",
   BACKTICK = "BACKTICK",
   COMMA = "COMMA",
@@ -9,6 +10,7 @@ export enum TokenKind {
   IDENTIFIER = "IDENTIFIER",
   MINUS = "MINUS",
   NUMBER = "NUMBER",
+  OR = "OR",
   PLUS = "PLUS",
   SELECT = "SELECT",
   SEMICOLON = "SEMICOLON",

test/lexer.test.ts

@@ -11,23 +11,27 @@ const scan = (source: string): Token[] | Error => {
 
 describe("Lexer", () => {
   it("scans uppercase keywords", () => {
-    const tokens = scan("SELECT FROM WHERE AS");
+    const tokens = scan("SELECT FROM WHERE AS AND OR");
     expect(tokens).to.deep.equal([
       new Token(TokenKind.SELECT, null, 1),
       new Token(TokenKind.FROM, null, 1),
       new Token(TokenKind.WHERE, null, 1),
       new Token(TokenKind.AS, null, 1),
+      new Token(TokenKind.AND, null, 1),
+      new Token(TokenKind.OR, null, 1),
       new Token(TokenKind.EOF, null, 1),
     ]);
   });
 
   it("scans lowercase keywords", () => {
-    const tokens = scan("select from where as");
+    const tokens = scan("select from where as and or");
     expect(tokens).to.deep.equal([
       new Token(TokenKind.SELECT, null, 1),
       new Token(TokenKind.FROM, null, 1),
       new Token(TokenKind.WHERE, null, 1),
       new Token(TokenKind.AS, null, 1),
+      new Token(TokenKind.AND, null, 1),
+      new Token(TokenKind.OR, null, 1),
       new Token(TokenKind.EOF, null, 1),
     ]);
   });