Support line comments.

HISTORY.markdown

@@ -6,6 +6,7 @@ History of SixtyPical
 
 *   Added `byte table` type locations and indexed addressing (`+ x`, `+ y`).
 *   Integer literals may be given in hexadecimal.
+*   Line comments may be included in source code by prefixing them with `//`.
 
 0.4
 ---

README.markdown

@@ -33,8 +33,6 @@ TODO
 
 For 0.5:
 
-*   source code comments.
-
 For 0.6:
 
 *   `interrupt` routines.

eg/screen2.60p

@@ -1,12 +1,16 @@
+// Displays 256 hearts at the top of the Commodore 64's screen.
+
+// Define where the screen starts in memory:
 byte table screen @ 1024
 
 routine main
+  // These are the values that will be written to by this routine:
   trashes a, x, z, n, screen
 {
     ld x, 0
-    ld a, 83
+    ld a, 83    // 83 = screen code for heart
     repeat {
         st a, screen + x
         inc x
-    } until z
+    } until z   // this flag will be set when x wraps around from 255 to 0
 }

src/sixtypical/parser.py

@@ -29,6 +29,8 @@ class Scanner(object):
 
     def scan(self):
         self.scan_pattern(r'[ \t\n\r]*', 'whitespace')
+        while self.scan_pattern(r'\/\/.*?[\n\r]', 'comment'):
+            self.scan_pattern(r'[ \t\n\r]*', 'whitespace')
         if not self.text:
             self.token = None
             self.type = 'EOF'

tests/SixtyPical Syntax.md

@@ -19,6 +19,16 @@ Rudimentary program.
     | }
     = ok
 
+Program with comments.
+
+    | // Welcome to my program.
+    | 
+    | routine main {
+    |     ld a, 0
+    |     add a, 1    // We are adding the thing.
+    | }
+    = ok
+
 Hex literals.
 
     | routine main {