variable support cleanup

src/basic/basic_commands/cmd__jumptable.s

@@ -19,7 +19,7 @@
 	cmd_input,
 	cmd_dim,
 	cmd_read,
-	cmd_let,
+	assign_variable,                   // cmd_let
 	cmd_goto,
 	cmd_run,
 	cmd_if,

src/basic/basic_operators/oper_add.s

@@ -36,13 +36,18 @@ oper_add_strings:
 
 	pla
 	sta __FAC2+0
-	beq oper_add_strings_end           // if string 2 is empty, we have nothing to do
+
+	// If string 2 is empty, release it and quit
+
+	beq oper_add_strings_end
 
 	// If string 1 is empty, just copy the metadata
 
 	lda __FAC1+0
 	bne !+
 
+	jsr tmpstr_free_FAC1
+
 	lda __FAC2+0
 	sta __FAC1+0
 	lda __FAC2+1
@@ -88,7 +93,7 @@ oper_add_strings:
 	// Increase INDEX pointer by the size of the 1st string
 
 	tya
-	jsr varstr_INDEX_up_A
+	jsr helper_INDEX_up_A
 
 	// Copy data from the second string
 
@@ -104,7 +109,7 @@ oper_add_strings:
 
 #elif CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-	jsr helper_add_concat
+	jsr helper_strconcat
 
 #else // CONFIG_MEMORY_MODEL_38K
 
@@ -121,7 +126,7 @@ oper_add_strings:
 	// Increase INDEX pointer by the size of the 1st string
 
 	tya
-	jsr varstr_INDEX_up_A
+	jsr helper_INDEX_up_A
 
 	// Copy data from the second string
 
@@ -135,11 +140,9 @@ oper_add_strings:
 
 #endif
 
-	// Free old strings - if they are temporary
+	// Free old FAC1 string - if it was temporary
 
-	// XXX
-	// XXX
-	// XXX
+	jsr tmpstr_free_FAC1
 
 	// Copy the descriptor to __FAC1
 
@@ -150,6 +153,9 @@ oper_add_strings:
 	dey
 	bpl !-
 
+	// FALLTROUGH
+
 oper_add_strings_end:
 
+	jsr tmpstr_free_FAC2
 	jmp FRMEVL_continue

src/basic/engine/tmpstr_free_all.s

@@ -1,10 +0,0 @@
-// #LAYOUT# STD *       #TAKE
-// #LAYOUT# *   BASIC_0 #TAKE
-// #LAYOUT# *   *       #IGNORE
-
-
-tmpstr_free_all:
-
-	// XXX implement this
-	
-	rts

src/basic/engine_runtime/execute_line_statements.s

@@ -250,4 +250,4 @@ execute_statements_var_assign:
 #else
 	dew TXTPTR
 #endif
-	jmp cmd_let
+	jmp assign_variable

src/basic/engine_variables/assign_variable.s

@@ -3,8 +3,7 @@
 // #LAYOUT# *   *       #IGNORE
 
 
-
-cmd_let:
+assign_variable:
 
 	// Fetch variable name, should be followed by assign operator
 
@@ -62,14 +61,14 @@ cmd_let:
 	// Determine what to assign
 
 	pla
-	bmi cmd_let_assign_string
-	beq cmd_let_assign_float
+	bmi assign_string
+	beq assign_float
 
 	// FALLTROUGH
 
 	// XXX integer and float probably have much in common
 
-cmd_let_assign_integer:
+assign_integer:
 
 	lda VALTYP
 	bmi_16 do_TYPE_MISMATCH_error
@@ -97,7 +96,7 @@ cmd_let_assign_integer:
 
 	jmp do_NOT_IMPLEMENTED_error
 
-cmd_let_assign_float:
+assign_float:
 
 	lda VALTYP
 	bmi_16 do_TYPE_MISMATCH_error
@@ -125,7 +124,7 @@ cmd_let_assign_float:
 
 	jmp do_NOT_IMPLEMENTED_error
 
-cmd_let_assign_string:
+assign_string:
 
 	// Check if value type matches
 	
@@ -134,12 +133,12 @@ cmd_let_assign_string:
 
 	// Copy the string descriptor to DSCPNT
 
-	jsr helper_let_strdesccpy
+	jsr helper_strdesccpy
 
 	// First special case - check if the new string has size 0
 
 	lda __FAC1+0
-	bne cmd_let_assign_string_not_empty
+	bne assign_string_not_empty
 
 	// Yes, it is empty - free the old one
 
@@ -159,41 +158,41 @@ cmd_let_assign_string:
 
 	rts
 
-cmd_let_assign_string_not_empty:
+assign_string_not_empty:
 
 	// Check if the source and destination strings are the same
 
 	lda DSCPNT+1
 	cmp __FAC1+1
-	bne cmd_let_assign_string_not_same
+	bne assign_string_not_same
 	iny
 	lda DSCPNT+2
 	cmp __FAC1+2
-	bne cmd_let_assign_string_not_same
+	bne assign_string_not_same
 
 	// If we are here, than both source and destination strings are the same - nothing more to be done
 
 	rts
 
-cmd_let_assign_string_not_same:
+assign_string_not_same:
 
 	// Strings are not the same - check if the new one is located within the text area, between TXTTAB and VARTAB
 
 	lda VARTAB+1
 	cmp __FAC1+2
-	bcc cmd_let_assign_string_not_text_area
+	bcc assign_string_not_text_area
 	bne !+
 	lda VARTAB+0
 	cmp __FAC1+1
-	bcc cmd_let_assign_string_not_text_area	
+	bcc assign_string_not_text_area	
 !:
 	lda __FAC1+2
 	cmp TXTTAB+1
-	bcc cmd_let_assign_string_not_text_area
+	bcc assign_string_not_text_area
 	bne !+
 	lda __FAC1+1
 	cmp TXTTAB+0
-	bcc cmd_let_assign_string_not_text_area
+	bcc assign_string_not_text_area
 !:
 	// String is located within text area - great, just copy the descriptor
 
@@ -227,7 +226,7 @@ cmd_let_assign_string_not_same:
 
 	rts
 
-cmd_let_assign_string_not_text_area:
+assign_string_not_text_area:
 
 	// Check if the new string is a temporary one - if so, reuse alocation
 
@@ -235,12 +234,12 @@ cmd_let_assign_string_not_text_area:
 
 	// Check if the old string belongs to the string area (is above FRETOP)
 
-	jsr varstr_cmp_fretop
-	bcc cmd_let_assign_string_no_optimizations
+	jsr helper_cmp_fretop
+	bcc assign_string_no_optimizations
 
 	// FALLTROUGH
 
-cmd_let_assign_string_try_reuse:
+assign_string_try_reuse:
 
 	// Check if we can reuse old string memory
 
@@ -249,9 +248,9 @@ cmd_let_assign_string_try_reuse:
 
 	// If size of both string equals - simply reuse it
 
-	beq_16 helper_let_strvarcpy
+	beq_16 helper_strvarcpy
 
-cmd_let_assign_string_try_reuse_unsuccesful:
+assign_string_try_reuse_unsuccesful:
 
 	// No special case optimization is possible - but first get rid of the old string
 
@@ -259,7 +258,7 @@ cmd_let_assign_string_try_reuse_unsuccesful:
 
 	// FALLTROUGH
 
-cmd_let_assign_string_no_optimizations:
+assign_string_no_optimizations:
 
 	// Allocate memory for the new string
 
@@ -281,4 +280,4 @@ cmd_let_assign_string_no_optimizations:
 
 	// Copy the string and quit
 
-	jmp helper_let_strvarcpy
+	jmp helper_strvarcpy

src/basic/engine_variables/fetch_variable_TI_string.s

@@ -11,7 +11,7 @@ fetch_variable_TI_string:
 
 	lda #$06
 	jsr tmpstr_alloc
-	jsr helper_let_strdesccpy
+	jsr helper_strdesccpy
 
 	// Fetch the time in a safe way, store it in temporary area
 

src/basic/engine_variables/helper_cmp_fretop.s

@@ -10,7 +10,7 @@
 // - Carry flag set - this string belongs to the string area
 
 
-varstr_cmp_fretop:
+helper_cmp_fretop:
 
 	lda DSCPNT+2
 	cmp FRETOP+1

src/basic/engine_variables/helper_fretop.s

@@ -3,10 +3,10 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routines for 'varstr_alloc'
+// Helper routines for FRETOP handling
 //
 
-varstr_FRETOP_down_A:                  // .A - bytes to lower FRETOP, uses DSCPNT+0
+helper_FRETOP_down_A:                  // .A - bytes to lower FRETOP, uses DSCPNT+0
 
 	sta DSCPNT+0 
 
@@ -19,7 +19,7 @@ varstr_FRETOP_down_A:                  // .A - bytes to lower FRETOP, uses DSCPN
 !:
 	// FALLTROUGH
 
-varstr_FRETOP_check:                   // check if FRETOP > STREND, Carry set if not
+helper_FRETOP_check:                   // check if FRETOP > STREND, Carry set if not
 
 	lda STREND+1
 	cmp FRETOP+1

src/basic/engine_variables/helper_fretop_up.s

@@ -3,11 +3,11 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routines for 'varstr_free'
+// Helper routine for FRETOP handling
 //
 
 
-varstr_FRETOP_up:                    // DSCPNT+0 - bytes to increment FRETO
+helper_FRETOP_up:                    // DSCPNT+0 - bytes to increment FRETO
 
 	clc
 	lda FRETOP+0

src/basic/engine_variables/helper_index_up_a_38K_60K.s

@@ -0,0 +1,24 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Helper routine, used by garbage collector and string concatenation
+//
+
+#if CONFIG_MEMORY_MODEL_38K || CONFIG_MEMORY_MODEL_60K
+
+helper_INDEX_up_A:                     // .A - bytes to increase TXTPTR, uses DSCPNT+0
+
+	sta DSCPNT+0 
+
+	clc
+	lda INDEX+0
+	adc DSCPNT+0 
+	sta INDEX+0
+	bcc !+
+	dec INDEX+1
+!:
+	rts
+
+#endif

src/basic/engine_variables/helper_index_up_a_46K_50K.s

@@ -8,8 +8,9 @@
 // Helper routine, used by garbage collector and string concatenation
 //
 
+#if CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-varstr_INDEX_up_A:                     // .A - bytes to increase TXTPTR, uses DSCPNT+0
+helper_INDEX_up_A:                     // .A - bytes to increase TXTPTR, uses DSCPNT+0
 
 	sta DSCPNT+0 
 
@@ -21,3 +22,5 @@ varstr_INDEX_up_A:                     // .A - bytes to increase TXTPTR, uses DS
 	dec INDEX+1
 !:
 	rts
+
+#endif

src/basic/engine_variables/helper_strconcat_46K_50K.s

@@ -11,7 +11,7 @@
 
 #if CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-helper_add_concat:
+helper_strconcat:
 
 	// Unmap BASIC lower ROM
 
@@ -31,7 +31,7 @@ helper_add_concat:
 	// Increase INDEX pointer by the size of the 1st string
 
 	tya
-	jsr varstr_INDEX_up_A
+	jsr helper_INDEX_up_A
 
 	// Copy data from the second string
 

src/basic/engine_variables/helper_strdesccpy_38K.s

@@ -3,13 +3,13 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routine to copy string descriptor, for LET command and TI$ variable support
+// Helper routine to copy string descriptor
 //
 
 
 #if CONFIG_MEMORY_MODEL_38K
 
-helper_let_strdesccpy:
+helper_strdesccpy:
 
 	ldy #$00
 	lda (VARPNT), y

src/basic/engine_variables/helper_strdesccpy_46K_50K.s

@@ -5,13 +5,13 @@
 // This has to go $E000 or above - routines below banks out the main BASIC ROM!
 
 //
-// Helper routine to copy string descriptor, for LET command and TI$ variable support
+// Helper routine to copy string descriptor
 //
 
 
 #if CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-helper_let_strdesccpy:
+helper_strdesccpy:
 
 	// Unmap BASIC lower ROM
 

src/basic/engine_variables/helper_strdesccpy_60K.s

@@ -3,13 +3,13 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routine to copy string descriptor, for LET command and TI$ variable support
+// Helper routine to copy string descriptor
 //
 
 
 #if CONFIG_MEMORY_MODEL_60K
 
-helper_let_strdesccpy:
+helper_strdesccpy:
 
 	ldx #<VARPNT
 

src/basic/engine_variables/helper_strvarcpy_38K.s

@@ -3,13 +3,13 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routine to copy string descriptor, for LET command
+// Helper routine to copy string descriptor
 //
 
 
 #if CONFIG_MEMORY_MODEL_38K
 
-helper_let_strvarcpy:
+helper_strvarcpy:
 
 	// Retrieve pointer to destination
 

src/basic/engine_variables/helper_strvarcpy_46K_50K.s

@@ -5,13 +5,13 @@
 // This has to go $E000 or above - routines below banks out the main BASIC ROM!
 
 //
-// Helper routine to copy string variable content, for LET command
+// Helper routine to copy string variable content
 //
 
 
 #if CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-helper_let_strvarcpy:
+helper_strvarcpy:
 
 	// Unmap BASIC lower ROM
 

src/basic/engine_variables/helper_strvarcpy_60K.s

@@ -3,13 +3,13 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Helper routine to copy string descriptor, for LET command
+// Helper routine to copy string descriptor
 //
 
 
 #if CONFIG_MEMORY_MODEL_60K
 
-helper_let_strvarcpy:
+helper_strvarcpy:
 
 	ldx #<VARPNT
 

src/basic/engine_variables/helper_txtptr_down.s

@@ -7,7 +7,7 @@
 //
 
 
-varstr_TXTPTR_down_A:                  // .A - bytes to decrease TXTPTR, uses DSCPNT+0
+helper_TXTPTR_down_A:                  // .A - bytes to decrease TXTPTR, uses DSCPNT+0
 
 	sta DSCPNT+0
 

src/basic/engine_variables/tmpstr_alloc.s

@@ -20,7 +20,7 @@ tmpstr_alloc:
 
 	lda TEMPPT
 	cmp #$22
-	bcs_16 do_FORMULA_TOO_COMPLEX_error
+	bcs tmpstr_alloc_try_reuse
 
 	tay
 	sta LASTPT
@@ -28,18 +28,43 @@ tmpstr_alloc:
 	adc #$03
 	sta TEMPPT
 
+	// FALLTROUGH
+
+tmpstr_alloc_found:
+
 	// Store desired string length
 
 	stx $00, y
 
 	// Store descriptor address
 
-	lda LASTPT
-	sta VARPNT+0
+	sty VARPNT+0
 	lda #$00
 	sta VARPNT+1
 
 	// Jump to alocation routine
-	// XXX consider falltrough
 
 	jmp varstr_alloc
+
+tmpstr_alloc_try_reuse:
+
+	// It seems there is no space left - try to find empty entry
+
+	ldy #$19
+
+	// FALLTROUGH
+
+tmpstr_alloc_try_reuse_loop:
+
+	lda $00, y
+	beq tmpstr_alloc_found             // branch if free entry found
+
+	iny
+	iny
+	iny
+	cpy #$22
+	bne tmpstr_alloc_try_reuse_loop
+
+	// Everything failed - give up
+
+	jmp do_FORMULA_TOO_COMPLEX_error

src/basic/engine_variables/tmpstr_free.s

@@ -0,0 +1,97 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Frees the string if it belongs to temporary string stack
+//
+// Input:
+// - DSCPNT+1/+2 - pointer to string (depending on the call addres, can fetch from FAC1/FAC2)
+//
+
+
+tmpstr_free_FAC1:
+
+	lda __FAC1+1
+	sta DSCPNT+1
+	lda __FAC1+2
+
+#if HAS_OPCODES_65C02
+	bra !+
+#else
+	jmp !+
+#endif
+
+tmpstr_free_FAC2:
+
+	lda __FAC2+1
+	sta DSCPNT+1
+	lda __FAC2+2
+!:
+	sta DSCPNT+2
+
+	// FALLTROUGH
+
+tmpstr_free:
+
+	// First find the descriptor matching the given string
+
+	ldx #$19
+
+	//FALLTROUGH
+
+tmpstr_free_loop:
+
+	cpx TEMPPT
+	bne !+
+	rts                                // quit if not found
+!:
+	// First fetch the string size - if 0, do not even try to compare
+
+	ldy $00, x
+	beq tmpstr_free_next_3
+
+	// Check if current string
+	
+	inx
+	lda $00, x
+	cmp DSCPNT+1
+	bne tmpstr_free_next_2
+
+	inx
+	lda $00, x
+	cmp DSCPNT+2
+	bne tmpstr_free_next_1
+
+	// This is the string we need to free
+
+	sty DSCPNT+0
+	phx_trash_a
+	jsr varstr_free
+	plx_trash_a
+
+	// Mark empty string as free and quit
+
+	dex
+	dex
+	lda #$00
+	sta $00, x
+
+	rts
+
+tmpstr_free_next_3:
+
+	inx
+
+	// FALLTROUGH
+
+tmpstr_free_next_2:
+
+	inx
+
+	// FALLTROUGH
+
+tmpstr_free_next_1:
+
+	inx
+	bne tmpstr_free_loop

src/basic/engine_variables/tmpstr_free_all.s

@@ -0,0 +1,20 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+
+tmpstr_free_all:
+
+	// Go through all the temporary descriptors and free everything
+
+	ldx #$19
+
+	// XXX implement this
+
+	//FALLTROUGH
+
+tmpstr_free_all_loop:
+
+	// XXX finish, deduplicate part with CLR
+	
+	rts

src/basic/engine_variables/varstr_alloc.s

@@ -48,14 +48,14 @@ varstr_alloc_retry:
 #if !HAS_OPCODES_65CE02
 
 	lda #$02
-	jsr varstr_FRETOP_down_A
+	jsr helper_FRETOP_down_A
 
 #else // HAS_OPCODES_65CE02 - this time code is slightly longer, but faster
 
 	dew FRETOP
 	dew FRETOP
 
-	jsr varstr_FRETOP_check
+	jsr helper_FRETOP_check
 
 #endif
 
@@ -95,7 +95,7 @@ varstr_alloc_retry:
 	lda (VARPNT),y
 #endif
 
-	jsr varstr_FRETOP_down_A
+	jsr helper_FRETOP_down_A
 	bcs varstr_alloc_fail
 
 	// Success - fill in the string descriptor

src/basic/engine_variables/varstr_free.s

@@ -20,9 +20,9 @@ varstr_free:
 	rts
 !:
 	// Check if string is above FRETOP (in string area)
-	// XXX consider moving this check out of this routine
+	// XXX move this check out of the routine
 
-	jsr varstr_cmp_fretop
+	jsr helper_cmp_fretop
 	bcs !+
 
 	// No, it does not belong to string area - quit
@@ -36,13 +36,13 @@ varstr_free:
 	// This is the lowest string - so just increase FRETOP, this way
 	// the garbage collector will not be needed that quickly
 
-	jsr varstr_FRETOP_up                         // free the string data
+	jsr helper_FRETOP_up                         // free the string data
 
 #if !HAS_OPCODES_65CE02
 
 	lda #$02                                     // free the back-pointer
 	sta DSCPNT+0
-	jmp varstr_FRETOP_up
+	jmp helper_FRETOP_up
 
 #else // HAS_OPCODES_65CE02
 

src/basic/engine_variables/varstr_garbage_collect.s

@@ -79,7 +79,7 @@ varstr_garbage_collect_check_bptr:
 
 #if !HAS_OPCODES_65CE02
 	lda #$02
-	jsr varstr_TXTPTR_down_A
+	jsr helper_TXTPTR_down_A
 #else // HAS_OPCODES_65CE02
 	dew TXTPTR
 	dew TXTPTR
@@ -271,7 +271,7 @@ varstr_garbage_collect_check_bptr:
 	lda (OLDTXT),y
 #endif
 
-	jsr varstr_TXTPTR_down_A
+	jsr helper_TXTPTR_down_A
 
 	// Check if variable descriptor in __FAC1 matches the previously moved string;
 	// if so - adapt it too
@@ -317,7 +317,7 @@ varstr_garbage_collect_unused:
 
 #if !HAS_OPCODES_65CE02
 	lda #$01
-	jsr varstr_TXTPTR_down_A
+	jsr helper_TXTPTR_down_A
 #else // HAS_OPCODES_65CE02
 	dew TXTPTR
 #endif
@@ -338,14 +338,14 @@ varstr_garbage_collect_unused:
 	// Increase INDEX (shift offset) by string length + back-pointer length
 
 	lda #$03
-	jsr varstr_INDEX_up_A
+	jsr helper_INDEX_up_A
 	txa
-	jsr varstr_INDEX_up_A
+	jsr helper_INDEX_up_A
 
 	// Decrease TXTPTR by unused string length-1
 
 	txa
-	jsr varstr_TXTPTR_down_A
+	jsr helper_TXTPTR_down_A
 
 	// Next iteration