code size optimization in BASIC

src/basic/engine_editor/tk_pack.s

@@ -144,7 +144,7 @@ tk_pack_loop_next:
 	cmp #TK__MAX_KEYWORD_LEN
 	beq !+                             // if max length reached - quit
 
-	// Check for characters that can only end the token
+	// Check for characters that can only end the keyword
 
 	lda BUF-1, x
 	cmp #$41

src/basic/engine_runtime/injest_assign.s

@@ -3,7 +3,7 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Consummes assign operator in a BASIC code, Carry set if not found. Injests all spaces.
+// Consummes assign operator in a BASIC code, triggers error if not found
 //
 
 
@@ -11,19 +11,6 @@ injest_assign:
 
 	jsr fetch_character_skip_spaces
 	cmp #$B2                           // assign operator character
-	beq injest_assign_found
+	bne_16 do_SYNTAX_error
-	
-	// Not found
-#if !HAS_OPCODES_65CE02
-	jsr unconsume_character
-#else
-	dew TXTPTR
-#endif
 
-	sec
-	rts
-
-injest_assign_found:
-
-	clc
 	rts

src/basic/engine_variables/array_create.s

@@ -47,15 +47,10 @@ array_create_fetch_dims_loop:
 
 	inx
 
-	// Check if the stack has reasonable space free
-
-	jsr check_stack_space
-
 	// Fetch the dimension, increment it by 1, and put it on the stack;
 	// confirmed with original ROM, that it also stores dimensions in the reverse order
 
-	jsr fetch_uint16
+	jsr helper_fetch_arr_coord
-	bcs_16 do_SYNTAX_error
 
 #if !HAS_OPCODES_65CE02
 	inc LINNUM+0
@@ -75,11 +70,8 @@ array_create_fetch_dims_loop:
 
 	// Check if more dimensions are given
 
-	jsr fetch_character_skip_spaces
+	cpy #$00
-	cmp #$2C                                     // ','
 	beq array_create_fetch_dims_loop
-	cmp #$29                                     // ')'
-	bne_16 do_SYNTAX_error
 
 	// FALLTROUGH
 

src/basic/engine_variables/assign_variable.s

@@ -5,26 +5,35 @@
 
 assign_variable:
 
-	// Fetch variable name, should be followed by assign operator
+	// Fetch variable/array name
 
 	jsr fetch_variable_name
-
-#if HAS_OPCODES_65CE02
-
-	bcs_16 do_SYNTAX_error
-	jsr injest_assign
 	bcs_16 do_SYNTAX_error
 
-#else
-
-	bcs !+
 	jsr injest_assign
-	bcc !++
-!:
-	jmp do_SYNTAX_error
-!:
 
-#endif
+	// Check for array
+
+	lda DIMFLG
+	bpl assign_variable_not_array
+
+	// Retrieve all the dimensions
+
+	// XXX implement this
+
+	jmp do_NOT_IMPLEMENTED_error
+
+	// Fetch assignment operator and continue
+
+	jsr injest_assign
+
+	jmp_8 assign_variable_common
+
+assign_variable_not_array:
+
+	// Require assignment operator
+
+	jsr injest_assign
 
 	// Check for special variables
 
@@ -37,8 +46,14 @@ assign_variable:
 	jsr is_var_ST
 	beq_16 do_SYNTAX_error
 
-	// Push the VARNAM to the stack - it might get overridden
+	// FALLTROUGH
 
+assign_variable_common:
+
+	// Push the DIMFLG and VARNAM to the stack - it might get overridden
+
+	lda DIMFLG
+	pha
 	lda VARNAM+0
 	pha
 	lda VARNAM+1
@@ -48,15 +63,18 @@ assign_variable:
 
 	jsr FRMEVL
 
-	// Restore VARNAM
+	// Restore VARNAM and DIMFLG
 
 	pla
 	sta VARNAM+1
 	pla
 	sta VARNAM+0
+	pla
+	sta DIMFLG // XXX is it needed?
+
+	// XXX add array handling here
 
 	// Retrieve the variable address
-	// XXX add support for arrays
 
 	jsr fetch_variable_find_addr
 

src/basic/engine_variables/fetch_variable_arr.s

@@ -27,27 +27,19 @@ fetch_variable_arr_fetch_coords_loop:
 
 	inx
 
-	// Check if the stack has reasonable space free
+	// Fetch the coordinate and put it on the stack
 
-	jsr check_stack_space
+	jsr helper_fetch_arr_coord
-
-	// Fetch the dimension and put it on the stack
-
-	jsr fetch_uint16
-	bcs_16 do_SYNTAX_error
 
 	lda LINNUM+0
 	pha
 	lda LINNUM+1
 	pha
 
-	// Check if more dimensions are given
+	// If more coordinates given - next iteration
 
-	jsr fetch_character_skip_spaces
+	cpy #$00
-	cmp #$2C                                     // ','
 	beq fetch_variable_arr_fetch_coords_loop
-	cmp #$29                                     // ')'
-	bne_16 do_SYNTAX_error
 
 	// FALLTROUGH
 

src/basic/engine_variables/helper_fetch_arr_coord.s

@@ -0,0 +1,42 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Helper routine for fetching array coordinates
+//
+// If this was last coordinate, set .Y to $FF, otherwise to $00
+//
+
+helper_fetch_arr_coord:
+
+	// Check if the stack has reasonable space free
+
+	jsr check_stack_space
+
+	// Fetch the dimension
+
+	jsr fetch_uint16
+	bcs !+
+
+	jsr fetch_character_skip_spaces
+	cmp #$2C                                     // ','
+	beq helper_fetch_arr_more
+	cmp #$29                                     // ')'
+	beq helper_fetch_arr_last
+
+	// FALLTROUGH
+
+!:
+
+	jmp do_SYNTAX_error
+
+helper_fetch_arr_more:
+
+	ldy #$00
+	rts
+
+helper_fetch_arr_last:
+
+	ldy #$FF
+	rts