From 37215cb72a8609ab3c060d150a2b69158aca956e Mon Sep 17 00:00:00 2001
From: Cat's Eye Technologies <cpressey@catseye.tc>
Date: Fri, 4 Apr 2014 16:54:25 +0100
Subject: [PATCH] Always emit `main` first.

---
 README.markdown                  |  1 +
 doc/Emitting.markdown            | 27 +++++++++++++++++++++------
 doc/Instruction_Support.markdown |  3 ---
 src/SixtyPical/Emitter.hs        | 10 +++++++---
 src/SixtyPical/Model.hs          |  5 +++++
 5 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/README.markdown b/README.markdown
index 8339974..9cb0926 100644
--- a/README.markdown
+++ b/README.markdown
@@ -119,3 +119,4 @@ TODO
 *   insist on EOL after each instruction.  need spacesWOEOL production
 *   asl .a
 *   `outputs` on externals
+*   Routine is a kind of StorageLocation?  (Location)?
diff --git a/doc/Emitting.markdown b/doc/Emitting.markdown
index e8c7561..ce9a052 100644
--- a/doc/Emitting.markdown
+++ b/doc/Emitting.markdown
@@ -19,7 +19,6 @@ Emitting an `if`.
     |    }
     |    sta screen
     | }
-    =   jmp main
     = main:
     =   lda screen
     =   cmp screen
@@ -47,7 +46,6 @@ Emitting a `repeat`.
     |    }
     |    sty screen
     | }
-    =   jmp main
     = main:
     =   ldy zero
     =   
@@ -79,7 +77,6 @@ Nested ifs.
     |     lda #3
     |   }
     | }
-    =   jmp main
     = main:
     =   BEQ _label_3
     =   lda #3
@@ -116,7 +113,6 @@ Installing an interrupt handler (at the Kernal level, i.e. with CINV)
     |   inc screen
     |   jmp (save_cinv)
     | }
-    =   jmp main
     = main:
     =   sei
     =   lda cinv
@@ -145,7 +141,6 @@ Copy command: immediate -> byte
     | routine main {
     |     copy #23 position
     | }
-    =   jmp main
     = main:
     =   lda #23
     =   sta position
@@ -159,7 +154,6 @@ Copy command: immediate -> word
     | routine main {
     |     copy #$0400 position
     | }
-    =   jmp main
     = main:
     =   lda #0
     =   sta position
@@ -168,3 +162,24 @@ Copy command: immediate -> word
     =   rts
     = 
     = position: .word 0
+
+`main` is always emitted first.
+
+    | reserve word position 
+    | routine foo {
+    |     inx
+    | }
+    | routine main {
+    |     jsr foo
+    |     jsr foo
+    | }
+    = main:
+    =   jsr foo
+    =   jsr foo
+    =   rts
+    = 
+    = foo:
+    =   inx
+    =   rts
+    = 
+    = position: .word 0
diff --git a/doc/Instruction_Support.markdown b/doc/Instruction_Support.markdown
index 1b58ee2..289fb3b 100644
--- a/doc/Instruction_Support.markdown
+++ b/doc/Instruction_Support.markdown
@@ -203,7 +203,6 @@ Big test for parsing and emitting instructions.
     |    ora #8
     |    ora vbyte
     | }
-    =   jmp main
     = main:
     =   lda #4
     =   ldx #0
@@ -277,7 +276,6 @@ Big test for parsing and emitting instructions.
     |    eor #5
     |    eor vbyte
     | }
-    =   jmp main
     = main:
     =   asl
     =   asl vbyte
@@ -307,7 +305,6 @@ Big test for parsing and emitting instructions.
     |        lda #2
     |    }
     | }
-    =   jmp main
     = main:
     =   pha
     =   sei
diff --git a/src/SixtyPical/Emitter.hs b/src/SixtyPical/Emitter.hs
index 5b97a97..f02007d 100644
--- a/src/SixtyPical/Emitter.hs
+++ b/src/SixtyPical/Emitter.hs
@@ -7,9 +7,13 @@ import Data.Bits
 import SixtyPical.Model
 
 emitProgram p@(Program decls routines) =
-    "  jmp main\n" ++
-    emitRoutines p routines ++
-    emitDecls p decls
+    let
+        mains = findRoutines (\(Routine name _ _) -> name == "main") routines
+        allElse = findRoutines (\(Routine name _ _) -> name /= "main") routines
+    in
+        emitRoutines p mains ++
+        emitRoutines p allElse ++
+        emitDecls p decls
 
 emitDecls _ [] = ""
 emitDecls p (decl:decls) =
diff --git a/src/SixtyPical/Model.hs b/src/SixtyPical/Model.hs
index cd4cd66..a43985d 100644
--- a/src/SixtyPical/Model.hs
+++ b/src/SixtyPical/Model.hs
@@ -176,3 +176,8 @@ lookupRoutine' [] _ = Nothing
 lookupRoutine' (rout@(Routine rname _ _):routs) name
     | rname == name = Just rout
     | otherwise     = lookupRoutine' routs name
+
+findRoutines f [] = []
+findRoutines f (rout:routs)
+    | f rout    = (rout:findRoutines f routs)
+    | otherwise = findRoutines f routs