From b15ddafa6ac227e909196f3b1299d70e046c4632 Mon Sep 17 00:00:00 2001
From: Paul Gardner-Stephen <paul@servalproject.org>
Date: Mon, 29 Apr 2019 22:05:27 +0930
Subject: [PATCH] allow multiple statements on single line. Issue #14

---
 c64/basic/basic_execute_line.s | 33 +++++++++++++++++++++++++++++++--
 c64/basic/cmd_list.s           |  3 +++
 c64/basic/cmd_new.s            |  7 ++++++-
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/c64/basic/basic_execute_line.s b/c64/basic/basic_execute_line.s
index 0bf25262..4b00dc37 100644
--- a/c64/basic/basic_execute_line.s
+++ b/c64/basic/basic_execute_line.s
@@ -1,10 +1,30 @@
+	;; Jump back into the BASIC execute line loop
+	;; after first checking that we have a colon
+	;; or $00 char
+
+basic_run_next_statement:
+	ldx #<basic_current_statement_ptr
+	ldy #0
+	jsr peek_under_roms
+
+	cmp #$00
+	beq +
+	cmp #$3a
+	beq +
+
+	;; Nope, so SYNTAX ERROR it is!
+	ldx #10
+	jmp do_basic_error
+
+*
+
 	;; Go through the line until its end is reached.
 	;; If we reach the end are in direct mode, then
 	;; go back to reading input, else look for the
 	;; next line, and advance to that, or else
 	;; return to READY prompt because we have run out
 	;; of program.
-
+	
 basic_execute_line:	
 
 	;; Get next char of program text, even if it is hiding under a ROM or the
@@ -26,6 +46,10 @@ basic_execute_line:
 	pha
 	lda basic_command_jump_table+0,x
 	pha
+
+	;; Now consume the character
+	jsr basic_consume_character
+	
 	rts	
 
 not_a_token:	
@@ -46,11 +70,16 @@ not_a_token:
 	jmp basic_main_loop
 
 basic_skip_char:
+	jsr basic_consume_character
+	jmp basic_execute_line
+
+basic_consume_character:
 	;; Advance basic text pointer
 	inc basic_current_statement_ptr+0
 	bne +
 	inc basic_current_statement_ptr+1
-*	jmp basic_execute_line
+*
+	rts
 	
 basic_end_of_line:
 
diff --git a/c64/basic/cmd_list.s b/c64/basic/cmd_list.s
index 108d1c57..9fd622e3 100644
--- a/c64/basic/cmd_list.s
+++ b/c64/basic/cmd_list.s
@@ -15,6 +15,9 @@ list_loop:
 	jsr peek_pointer_null_check
 	bcs list_more_lines
 
+	;; LIST terminates any running program,
+	;; because it has fiddled with the current line pointer.
+	;; (Confirmed by testing on a C64)
 	jmp basic_main_loop
 
 list_more_lines:
diff --git a/c64/basic/cmd_new.s b/c64/basic/cmd_new.s
index 2f5ff13c..3f3f2873 100644
--- a/c64/basic/cmd_new.s
+++ b/c64/basic/cmd_new.s
@@ -1,11 +1,16 @@
 
 cmd_new:
 	jsr basic_do_new
+
+	;; NEW command terminates execution
+	;; (Confirmed on a C64)
 	jmp basic_main_loop
 
 cmd_clr:
 	jsr basic_do_clr
-	jmp basic_main_loop
+	;; CLR command does not stop execution
+	;; (Cconfirmed on a c64)
+	jmp basic_run_next_statement
 	
 basic_do_new:	
 	;; Setup pointers to memory storage