+PUSH_NEWLINE_CHAR:
+ dq .start
+.start:
+ push $A
+ next
+
+NEWLINE:
+ dq docol
+ dq PUSH_NEWLINE_CHAR
+ dq EMIT
+ dq EXIT
+
+;; Read a word from standard input and push it onto the stack as a pointer and a
+;; size. The pointer is valid until the next call to READ_WORD.
+READ_WORD: ; 400170
+ dq .start
+.start:
+ mov [.rsi], rsi
+ mov [.rax], rax
+
+.skip_whitespace:
+ ;; Read characters into .char_buffer until one of them is not whitespace.
+ mov rax, 0
+ mov rdi, 0
+ mov rsi, .char_buffer
+ mov rdx, 1
+ syscall
+
+ cmp [.char_buffer], ' '
+ je .skip_whitespace
+ cmp [.char_buffer], $A
+ je .skip_whitespace
+
+.alpha:
+ ;; We got a character that wasn't whitespace. Now read the actual word.
+ mov [.length], 0
+
+.read_alpha:
+ mov al, [.char_buffer]
+ movzx rbx, [.length]
+ mov rsi, .buffer
+ add rsi, rbx
+ mov [rsi], al
+ inc [.length]
+
+ mov rax, 0
+ mov rdi, 0
+ mov rsi, .char_buffer
+ mov rdx, 1
+ syscall
+
+ cmp [.char_buffer], ' '
+ je .end
+ cmp [.char_buffer], $A
+ jne .read_alpha
+
+.end:
+ push .buffer
+ movzx rax, [.length]
+ push rax
+
+ mov rsi, [.rsi]
+ mov rax, [.rax]
+
+ next
+