Fixed some bugs with inputs

source/kernel/programs/ed.asm

@@ -1,18 +1,19 @@
 ; Planned commands:
 ; i insert
 ; a append
+; d delete
 ; l prints lines
 ; w save to disk
 ; q quit
 ed:
 	pusha
-	mov si, ed_welcome
-	call os_print_string
+	call .determine_line_count
 	.main_loop:
 		mov ax, ed_prompt
 		mov bx, 40
 		call keyboard_display_input ; AX = string location, BX = max prompt length
 		mov si, ed_prompt
+		mov bx, 0 ; Keeps track of whether comma has passed
 		jmp .get_token
 
 	; Types of tokens:
@@ -20,16 +21,138 @@ ed:
 	; Doller (refers to the last line) $
 	; Comma ,
 	; Command: eg i
-	; 123
+	; eg 123,127i
 	.get_token:
-		xor ax,ax
 		lodsb
-		call check_is_number
-		jmp .exit
 
-	.exit:
+		; COMMA
+		cmp al, ','
+		je .comma
+
+		; NUMBER
+		call check_is_number
+		jc .get_number_token
+
+		; COMMAND
+		call check_is_letter
+		jc .get_letter_token
+
+	.error: ; Output ?
+		mov ah, 0Eh
+
+		mov al, '?'
+		int 10h
+		mov al, 0Ah
+		int 10h
+		mov al, 0Dh
+		int 10h
+		
+		jmp .main_loop
+
+	; Assign a number to either the start or end int (start,end)
+	.get_number_token:
+		push si
+		dec si
+		call string_cast_to_int ; AX = integer
+		cmp bx, 0
+		je .assign_start_int
+		jg .assign_end_int
+	.assign_start_int:
+		mov [ed_start_int], ax
+		jmp .after_int_assign
+	.assign_end_int:
+		mov [ed_end_int], ax
+	.after_int_assign:
+		pop si
+		jmp .get_token
+
+	; Determines a command
+	.get_letter_token:
+		cmp al, 'd'
+		je .delete
+		cmp al, 'q'
+		je .quit
+		jmp .get_token
+
+	; Changes the value from start int to end int
+	.comma:
+		mov bx, 1
+		jmp .get_token
+
+	.determine_line_count:
+		mov si, file_buffer
+		mov dx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
+		xor cx,cx
+		.line_count_loop:
+			lodsb
+			cmp al, 0Ah
+			je .increment_line_count
+			dec dx
+			cmp dx, 0
+			jg .line_count_loop
+		mov [ed_line_count], cx
+		jmp .main_loop
+		.increment_line_count:
+			inc cx
+			jmp .line_count_loop
+
+	; COMMANDS
+	.delete:
+		; set up registers to shift data left
+		mov bx, ed_end_int
+		inc bx
+		call get_byte_of_line ; CX = byte of start of new line (relative to file buffer)
+		mov [ed_shift_from], cx
+
+		mov bx, ed_start_int
+		call get_byte_of_line
+		mov ax, ed_start_int
+		sub ax, cx
+		mov [ed_shift_by], ax
+
+	.quit:
 		popa
 		ret
 
+shift_data_left:
+	mov si, ed_shift_from
+	mov cx, ed_shift_by
+	mov di, ed_shift_from
+	sub di, cx
+	mov dx, file_length ; STORES THE LENGTH OF THE FILE IN BYTES
+	.shift_left_loop:
+		lodsb
+		stosb
+		cmp al, 0
+		jne .shift_left_loop
+	jmp ed.main_loop
+
+; BX = target line
+get_byte_of_line:
+	push dx
+	mov si, file_buffer
+	xor dx,dx
+	xor cx,cx
+	jmp .increment_line_count
+	.line_loop:
+		lodsb
+		inc cx
+		cmp al, 0Ah
+		je .increment_line_count
+	.increment_line_count:
+		inc dx
+		cmp dx, bx
+		jne .line_loop
+		inc cx
+		pop dx
+		ret
+
+ed_data_start: db "ED IS COOL"
 ed_prompt:	times 40 db 0
-ed_welcome: db "This is ED\n", 0
+ed_start_int: dw 0
+ed_end_int: dw 0
+
+ed_line_count: dw 0
+
+ed_shift_from: dw 0
+ed_shift_by: dw 0