From 1cf166f0dbc955aac2bea701415124976c82bb59 Mon Sep 17 00:00:00 2001
From: Cat's Eye Technologies <cpressey@catseye.tc>
Date: Wed, 2 Apr 2014 17:10:21 +0100
Subject: [PATCH] Allow comments.

---
 README.markdown          | 20 +++++++++++++++++++-
 src/SixtyPical/Parser.hs | 18 ++++++++++++++++--
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/README.markdown b/README.markdown
index aecfb07..7968c24 100644
--- a/README.markdown
+++ b/README.markdown
@@ -262,7 +262,6 @@ In these, `absolute` must be a `reserve`d or `locate`d address.
 TODO
 ----
 
-*   comments
 *   Initial values for reserved, incl. tables
 *   give length for tables, must be there for reserved
 *   Character tables ("strings" to everybody else)
@@ -295,6 +294,25 @@ Tests
     | }
     ? missing 'main' routine
 
+A comment may appear at the start of a block.
+
+    | routine main {
+    |    ; this program does nothing
+    |    nop
+    | }
+    = True
+
+A comment may appear after each command.
+
+    | routine main {
+    |    lda #1   ; we assemble the fnord using
+    |    ldx #1   ; multiple lorem ipsums which
+    |    ldy #1
+    |    lda #1   ; we
+    |    ldx #1   ; found under the bridge by the old mill yesterday
+    | }
+    = True
+
 A program may `reserve` and `assign`.
 
     | reserve byte lives
diff --git a/src/SixtyPical/Parser.hs b/src/SixtyPical/Parser.hs
index 0909c7e..8c14949 100644
--- a/src/SixtyPical/Parser.hs
+++ b/src/SixtyPical/Parser.hs
@@ -16,7 +16,7 @@ Decl     := "reserve" StorageType LocationName
           | "external" RoutineName Address.
 StorageType := "byte" | "word" | "vector".
 Routine  := "routine" RoutineName Block.
-Block    := "{" {Command} "}".
+Block    := "{" [Comment] {Command [Comment]} "}".
 Command  := "if" Branch Block "else" Block
           | "lda" (LocationName | Immediate)
           | "ldx" (LocationName | Immediate)
@@ -90,11 +90,19 @@ block :: Parser [Instruction]
 block = do
     string "{"
     spaces
-    cs <- many command
+    optional comment
+    cs <- many commented_command
     string "}"
     spaces
     return cs
 
+comment :: Parser ()
+comment = do
+    string ";"
+    manyTill anyChar (try (string "\n"))
+    spaces
+    return ()
+
 -- -- -- -- -- -- commands -- -- -- -- --
 
 immediate :: (DataValue -> Instruction) -> Parser Instruction
@@ -124,6 +132,12 @@ absolute_indexed f = do
     indexes <- many index
     return $ f l indexes
 
+commented_command :: Parser Instruction
+commented_command = do
+    c <- command
+    optional comment
+    return c
+
 command :: Parser Instruction
 command = (try lda) <|>
           (try ldx) <|> (try ldy) <|>