Support both single and double quotes for strings (#10)

segmentio · Apr 16, 2019 · ebc37a2 · ebc37a2
1 parent 78c311b
commit ebc37a2
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/src/lexer.test.ts b/src/lexer.test.ts
@@ -128,7 +128,11 @@ test('Lexer passes Strings fixtures', () => {
     fix('"d"', [t.String('"d"'), t.EOS()], false),
     fix('"and"', [t.String('"and"'), t.EOS()], false),
     fix('"or and"', [t.String('"or and"'), t.EOS()], false),
-    fix('"a" "b"', [t.String('"a"'), t.String('"b"'), t.EOS()], false)
+    fix('"a" "b"', [t.String('"a"'), t.String('"b"'), t.EOS()], false),
+    fix('\'a\'', [t.String('\'a\''), t.EOS()], false),
+    fix('\'and\'', [t.String('\'and\''), t.EOS()], false),
+    fix('\'or and\'', [t.String('\'or and\''), t.EOS()], false),
+    fix('\'a\' \'b\'', [t.String('\'a\''), t.String('\'b\''), t.EOS()], false)
   ])
 })
 

diff --git a/src/lexer.ts b/src/lexer.ts
@@ -79,8 +79,8 @@ export class Lexer {
         continue
       }
 
-      if (char === '"') {
-        tokens.push(this.lexString())
+      if (char === '"' || char === '\'') {
+        tokens.push(this.lexString(char))
         continue
       }
 
@@ -118,9 +118,10 @@ export class Lexer {
     }
   }
 
-  private lexString(): Token {
+  private lexString(openQuote: string): Token {
     let str = ''
-    while (this.peek() !== '"') {
+    // Looking for closing string of same type of quote (single or double)
+    while (this.peek() !== openQuote) {
       const { char, isEOS } = this.next()
       str += char
 
@@ -133,8 +134,8 @@ export class Lexer {
       }
     }
 
-    this.accept('"') // Eat the last quote
-    return t.String(`"${str}"`)
+    this.accept(openQuote) // Eat the last quote
+    return t.String(`${openQuote}${str}${openQuote}`)
   }
 
   private lexNumber(previous: string): Token {