implement beginnings of BASIC main loop execution

c64/basic/basic_execute_line.s

@@ -16,6 +16,19 @@ basic_execute_line:
 	;; The checks should be done in order of frequency, so that we are as
 	;; fast as possible.
 
+	cmp #$7f
+	bcc not_a_token
+	;; It's a token: So get the jump table entry for it, push it on the stack
+	;; and then RTS to start it.
+	asl
+	tax
+	lda basic_command_jump_table+1,x
+	pha
+	lda basic_command_jump_table+0,x
+	pha
+	rts	
+
+not_a_token:	
 	;; Space, which we can also just ignore
 	cmp #$20
 	beq basic_skip_char
@@ -45,3 +58,150 @@ basic_end_of_line:
 	;; one.
 	
 	jmp basic_main_loop
+
+basic_command_jump_table:
+	;; $80 - $8F
+	.word cmd_end-1
+	.word cmd_for-1
+	.word cmd_next-1
+	.word cmd_data-1
+	.word cmd_inputhash-1
+	.word cmd_input-1
+	.word cmd_dim-1
+	.word cmd_read-1
+	.word cmd_let-1
+	.word cmd_goto-1
+	.word cmd_run-1
+	.word cmd_if-1
+	.word cmd_restore-1
+	.word cmd_gosub-1
+	.word cmd_return	-1
+	.word cmd_rem-1
+
+	;; $90-$9F
+	.word cmd_stop-1
+	.word cmd_on-1
+	.word cmd_wait-1
+	.word cmd_load-1
+	.word cmd_save-1
+	.word cmd_verify-1
+	.word cmd_def-1
+	.word cmd_poke-1
+	.word cmd_printhash-1
+	.word cmd_print-1
+	.word cmd_cont-1
+	.word cmd_list-1
+	.word cmd_clr-1
+	.word cmd_cmd-1
+	.word cmd_sys-1
+	.word cmd_open-1
+
+	;; $A0-$AF
+	.word cmd_close-1
+	.word cmd_get-1
+	.word cmd_new-1
+	.word cmd_tab-1
+	.word cmd_to-1
+	.word cmd_fn-1
+	.word cmd_spc-1
+	.word cmd_then-1
+	.word cmd_not-1
+	.word cmd_step-1
+	.word cmd_plus-1
+	.word cmd_minus-1
+	.word cmd_mult-1
+	.word cmd_div-1
+	.word cmd_exponent-1
+	.word cmd_and-1
+
+	;; $B0-$BF
+	.word cmd_or-1
+	.word cmd_greater-1
+	.word cmd_equal-1
+	.word cmd_less-1
+	.word cmd_sgn-1
+	.word cmd_int-1
+	.word cmd_abs-1
+	.word cmd_usr-1
+	.word cmd_fre-1
+	.word cmd_pos-1
+	.word cmd_sqr-1
+	.word cmd_rnd-1
+	.word cmd_log-1
+	.word cmd_exp-1
+	.word cmd_cos-1
+	.word cmd_sin-1
+
+	;; $C0-$CF
+	.word cmd_tan-1
+	.word cmd_atn-1
+	.word cmd_peek-1
+	.word cmd_len-1
+	.word cmd_str-1
+	.word cmd_val-1
+	.word cmd_asc-1
+	.word cmd_chr-1
+	.word cmd_left-1
+	.word cmd_right-1
+	.word cmd_mid-1
+	.word cmd_go-1 	
+	;; Undefined tokens
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+
+	;; $D0-$DF
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+
+	;; $E0-$EF
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+
+	;; $F0-$FF
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+	.word cmd_unimplemented-1
+