some more work on string assignment

src/basic/basic_commands/cmd_let.s

@@ -117,6 +117,77 @@ cmd_let_assign_string:
 	lda VALTYP
 	bpl_16 do_TYPE_MISMATCH_error
 
+	// Copy the string descriptor to DSCPNT
+
+#if CONFIG_MEMORY_MODEL_60K
+	
+	// XXX
+	// XXX: implement this
+	// XXX
+
+#elif CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
+	// XXX consider optimized version without multiple JSRs
+
+	// XXX
+	// XXX: implement this
+	// XXX
+
+#else // CONFIG_MEMORY_MODEL_38K
+
+	ldy #$00
+	lda (VARPNT), y
+	sta DSCPNT+0
+	iny
+	lda (VARPNT), y
+	sta DSCPNT+1
+	iny
+	lda (VARPNT), y
+	sta DSCPNT+2
+
+#endif
+
+	// First special case - check if the new string has size 0
+
+	// XXX
+
+	// Check if the source and destination strings are the same (VARPNT should now point just after variable name)
+
+	lda VARPNT+1
+	cmp __FAC1+1
+	bne !+
+	iny
+	lda VARPNT+2
+	cmp __FAC1+2
+	bne !+
+
+	// If we are here, than both source and destination strings are the same - nothing more to be done
+
+	rts
+!:
+	// Strings are not the same - check if the new one is located within a text area, between TXTTAB and VARTAB
+
+	// XXX
+
+	// Check if size of both equals and the old on is above FRETOP
+
+	// XXX
+
+	// Check if new one is at least 3 bytes shorter and the old one is above FRETOP
+
+	// XXX
+
+	// Free the memory of the old string, it is not possible to reuse it
+
+	// XXX
+
+	// Check if the new string is a temporary one - if so, reuse already done alocation
+
+	// XXX
+
+	// No special case optimization is possible - alocate new memory area and copy the string
+
+	// XXX
+
 #if CONFIG_MEMORY_MODEL_60K
 	
 	// XXX