more BASIC cleanup

c64/basic/basic_execute_line.s

@@ -1,164 +0,0 @@
-// #LAYOUT# STD *       #TAKE
-// #LAYOUT# *   BASIC_0 #TAKE
-// #LAYOUT# *   *       #IGNORE
-
-//
-// Tries to execute the statement, and all the subsequent ones
-//
-
-
-basic_execute_statement:
-
-	// Check for RUN/STOP
-
-	lda STKEY
-	bpl_16 cmd_stop
-
-	// Skip over any white spaces and colons (':')
-!:
-	jsr fetch_character
-	cmp #$20                           // space, can be skipped
-	beq !-
-	cmp #$3A                           // colon, can be skipped
-	beq !-
-	
-	// Check if end of the line
-
-	cmp #$00
-	beq basic_end_of_line
-
-	// Not end of the line - we actually have something to execute	
-
-	// XXX continue rework from here
-
-	pha
-	jsr unconsume_character
-	pla
-
-	// The checks should be done in order of frequency, so that we are as
-	// fast as possible.
-
-	cmp #$7f
-	bcc not_a_token
-
-	// It is a token - consume this character
-
-	jsr consume_character
-
-#if !HAS_OPCODES_65C02
-
-	// Get the jump table entry for it, push it on the stack, and then RTS to start it.
-
-	tax
-	lda command_jumptable_hi - $80, x
-	pha
-	lda command_jumptable_lo - $80, x
-	pha
-	
-	rts
-
-#else // HAS_OPCODES_65C02
-
-	asl
-	tax
-	jmp (command_jumptable, x)
-
-#endif
-
-not_a_token:
-	// Space, which we can also just ignore
-	cmp #$20
-	beq basic_skip_char
-	// End of line?
-	cmp #$00
-	beq basic_end_of_line
-	// :, i.e., statement separator, which we can simply ignore
-	cmp #$3a
-	beq basic_skip_char
-	
-	// If all else fails, it is a syntax error
-	jmp do_SYNTAX_error
-
-basic_skip_char:
-	jsr consume_character
-	jmp basic_execute_statement
-
-
-
-	
-basic_end_of_line:
-
-	// If we reach the end are in direct mode, then
-	// go back to reading input, else look for the
-	// next line, and advance to that, or else
-	// return to READY prompt because we have run out
-	// of program.
-
-	// XXX - If not in direct mode, then advance to next line, if there is
-	// one.
-
-	// Are we in direct mode
-	lda CURLIN+1
-	cmp #$ff
-	bne basic_not_direct_mode
-
-	// Yes, we were in direct mode, so stop now
-	jmp basic_main_loop
-
-basic_not_direct_mode:
-	// Copy line number to previous line number
-	lda CURLIN+0
-	sta OLDLIN+0
-	lda CURLIN+1
-	sta OLDLIN+1
-	
-	// Advance the basic line pointer to the next line
-	jsr basic_follow_link_to_next_line
-
-	// Are we at the end of the program?
-	lda OLDTXT+0
-	ora OLDTXT+1
-	bne basic_execute_from_current_line
-
-	// End of program found
-	jmp basic_main_loop
-	
-basic_execute_from_current_line:
-	// Check if pointer is null, if so, we are at the end of
-	// the program.
-	ldy #0
-	jsr peek_line_pointer_null_check
-	bcs !+
-	// End of program reached
-	jmp basic_main_loop
-!:
-	// Skip pointer and line number to get address of first statement
-	lda OLDTXT+0
-	clc
-	adc #4
-	sta TXTPTR+0
-	lda OLDTXT+1
-	adc #0
-	sta TXTPTR+1
-
-	ldy #2
-
-#if CONFIG_MEMORY_MODEL_60K
-	ldx #<OLDTXT
-	jsr peek_under_roms
-#else // CONFIG_MEMORY_MODEL_38K
-	lda (OLDTXT),y
-#endif
-
-	sta CURLIN+0
-	iny
-
-#if CONFIG_MEMORY_MODEL_60K
-	jsr peek_under_roms
-#else // CONFIG_MEMORY_MODEL_38K
-	lda (OLDTXT),y
-#endif
-
-	sta CURLIN+1
-
-	jmp basic_execute_statement

c64/basic/basic_main_loop.s

@@ -5,10 +5,6 @@
 
 basic_main_loop:
 
-	// XXX - Check if direct or program mode, and get next line of input
-	// the appropriate way.
-	// XXX - For now, it is hard coded to direct mode
-
 	// Tell user we are ready
 	jsr ready_message
 
@@ -177,4 +173,4 @@ not_a_line:
 	lda #$FF
 	sta CURLIN+1
 
-	jmp basic_execute_statement
+	jmp execute_statements

c64/basic/commands/cmd_clr.s

@@ -7,6 +7,6 @@ cmd_clr:
 
 	jsr basic_do_clr
 
-	// CLR command does not stop execution
+	// CLR command does not stop execution (confirmed on a C64)
-	// (Cconfirmed on a c64)
+
-	jmp basic_execute_statement
+	jmp execute_statements

c64/basic/commands/cmd_load_verify.s

@@ -65,7 +65,7 @@ cmd_load_no_error:
 	// For VERIFY - this is it
 
 	lda VERCKB
-	bne_16 basic_execute_statement
+	bne_16 execute_statements
 
 	// C64 BASIC apparently does not clear variables after a LOAD in the
 	// middle of a program. For safety, we do.
@@ -89,7 +89,7 @@ cmd_load_no_error:
 	inx
 	beq cmd_load_end                   // branch if direct mode
 
-	jmp basic_execute_from_current_line
+	jmp execute_line
 
 cmd_load_end:
 

c64/basic/commands/cmd_new.s

@@ -7,6 +7,6 @@ cmd_new:
 
 	jsr basic_do_new
 
-	// NEW command terminates execution
+	// NEW command terminates execution (confirmed on a C64)
-	// (Confirmed on a C64)
+
 	jmp basic_main_loop

c64/basic/commands/cmd_print.s

@@ -85,4 +85,4 @@ cmd_print_new_line_done:
 
 cmd_print_done:
 
-	jmp basic_execute_statement
+	jmp execute_statements

c64/basic/commands/cmd_rem.s

@@ -6,4 +6,5 @@
 // REM statement just skips to the next line
 
 cmd_rem:
-	jmp basic_end_of_line
+
+	jmp execute_statements_end_of_line

c64/basic/commands/cmd_run.s

@@ -24,4 +24,4 @@ cmd_goto:
 	jmp do_UNDEFD_STATEMENT_error
 !:
 	// Run it!
-	jmp basic_execute_from_current_line
+	jmp execute_line

c64/basic/commands/cmd_save.s

@@ -36,4 +36,4 @@ cmd_save:
 
 	// The end
 
-	jmp basic_execute_statement
+	jmp execute_statements

c64/basic/commands/cmd_sys.s

@@ -62,7 +62,7 @@ cmd_sys_setup_call:
 	// Call the routine.
 	jsr USRPOK
 	
-	jmp basic_execute_statement
+	jmp execute_statements
 
 
 	//

c64/basic/commands/command_jumptable.s

@@ -7,6 +7,9 @@
 //
 
 
+// XXX use separate jumptables for commands and functions
+
+
 .const command_list = List().add(
 
 	// $80 - $8F

c64/basic/engine/execute_line_statements.s

@@ -0,0 +1,124 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Tries to execute the statement, and all the subsequent ones
+//
+
+
+execute_statements:
+
+	// Check for RUN/STOP
+
+	lda STKEY
+	bpl_16 cmd_stop
+
+	// Skip over any white spaces and colons (':')
+!:
+	jsr fetch_character
+	cmp #$20                           // space, can be skipped
+	beq !-
+	cmp #$3A                           // colon, can be skipped
+	beq !-
+	
+	// Check if end of the line
+
+	cmp #$00
+	beq execute_statements_end_of_line
+
+	// Not end of the line - it seems we actually have something to execute	
+
+	cmp #$7F
+	bcc_16 do_SYNTAX_error             // branch if not a token    XXX here we should handle variable assignments
+
+#if !HAS_OPCODES_65C02
+
+	// Get the jump table entry for it, push it on the stack, and then RTS to start it.
+
+	tax
+	lda command_jumptable_hi - $80, x
+	pha
+	lda command_jumptable_lo - $80, x
+	pha
+	
+	rts
+
+#else // HAS_OPCODES_65C02
+
+	// Use jumptable to go to the token
+
+	asl
+	tax
+	jmp (command_jumptable, x)
+
+#endif
+
+
+execute_statements_end_of_line:
+
+	// First check, if we are in direct mode - if so,
+	// end the execution and go to main loop
+
+	ldx CURLIN+1
+	inx
+	beq_16 basic_main_loop
+
+	// Advance to the next line - first copy the line number
+	// to previous line number
+
+	lda CURLIN+0
+	sta OLDLIN+0
+	lda CURLIN+1
+	sta OLDLIN+1
+		
+	// Advance the basic line pointer to the next line; if end,
+	// go to the main loop
+
+	jsr basic_follow_link_to_next_line
+
+	lda OLDTXT+0
+	ora OLDTXT+1
+	beq_16 basic_main_loop
+	
+	// FALLTROUGH
+
+execute_line:
+
+	// Check if pointer is null, if so, we are at the end of the program
+
+	ldy #0
+	jsr peek_line_pointer_null_check
+	bcc_16 basic_main_loop             // branch if end of program reached
+
+	// Skip pointer and line number to get address of first statement
+
+	lda OLDTXT+0
+	clc
+	adc #$04
+	sta TXTPTR+0
+	lda OLDTXT+1
+	adc #$00
+	sta TXTPTR+1
+
+	ldy #$02
+
+#if CONFIG_MEMORY_MODEL_60K
+	ldx #<OLDTXT
+	jsr peek_under_roms
+#else // CONFIG_MEMORY_MODEL_38K
+	lda (OLDTXT),y
+#endif
+
+	sta CURLIN+0
+	iny
+
+#if CONFIG_MEMORY_MODEL_60K
+	jsr peek_under_roms
+#else // CONFIG_MEMORY_MODEL_38K
+	lda (OLDTXT),y
+#endif
+
+	sta CURLIN+1
+
+	jmp execute_statements

c64/basic/wedge/wedge_dos.s

@@ -98,7 +98,7 @@ wedge_dos_change_drive:
 !:
 	sta FA
 	jsr print_return
-	jmp basic_end_of_line
+	jmp basic_main_loop
 
 wedge_dos_status_get: