;;; This file contains words dealing with word lists (vocabularies)
;;;
;;; CURRENT-WORDLIST (variable) points out "the current wordlist"
;;; SYSCALLS is a wordl list
;;; FORTH is a word list
;;;
;;; !! When a word list word is created, it gets added to the tail end
;;; of the current word list as way of making all word list words be
;;; present in all word lists. This is different to all other kinds of
;;; words, which instead are added to the head end of the current word
;;; list.
;;;
;;; !! A word list word is created, it is initialised to the head end
;;; of the current word list. It will this be an extension to that
;;; current word list.
;;;
;;; EMPTY-WORDLIST is a word list word for an empty word list. It thus
;;; only contains word list words.
;;; 
;;; WORDLIST ( "name" -- ) = start

	WORD p_tfa2cfa,'TFA>CFA',fasm
	;; ( tfa -- cfa )
	;; Advance a word tfa pointer to the cfa field
	mov rax,qword[rsp]
	tfa2cfa rax
	mov qword [rsp],rax
	next
	
	WORD p_tfa2dfa,'TFA>DFA',fasm
	;; ( tfa -- dfa )
	;; Advance a word tfa pointer to the dfa field
	mov rax,qword[rsp]
	tfa2dfa rax
	mov qword [rsp],rax
	next

	WORD p_dfa2tfa,'DFA>TFA',fasm
	;; ( dfa -- tfa )
	;; Advance a word tfa pointer to the dfa field
	mov rax,qword[rsp]
	mov rax,qword [rax-24]	; tfa
	mov qword [rsp],rax
	next

	WORD p_wordlist,'CURRENT-WORDLIST',dovariable
	;; CURRENT-WORDLIST points to cfa of the currently active wordlist.
	dq p_forth_DFA

	WORD p_words,'WORDS',fasm
	;; ( -- )
	;; Dump all words
	pushr rsi
	mov rax,qword [p_wordlist_DFA] ; current wordlist word
	mov rax,[rax]		       ; list start
	sub rsp,8		       ; use stack to hold ptr
p_words_LOOP:
	mov qword [rsp],rax
	cmp rax,0
	je p_words_END
	;; tfa>pfa
	tfa2pfa rax
	push 1
	;; pfa@ => ( chars* length)
	pushpname rax
	DOFORTH sys_write
	pop rax			; ignore errors
	push qword 10
	DOFORTH p_emit
	mov rax,qword [rsp]
	mov rax,qword [rax]
	jmp p_words_LOOP

p_words_END:
	popr rsi
	next

	WORD p_strncmp,'STRNCMP',fasm
	;; ( chars1 chars2 n -- flag )
	;; Compare bytes until one is NUL, return <0, =0 or >0 to
	;; indicate that chars1 is lesser, they are equal, or chars2
	;; is lesser in ascii ordering respectively.
	pop rdx
	pop rbx
	pop rax
	xor rcx,rcx
	;; rax = chars1, rbx = chars2, cl = byte acc, rdx = length
	inc rdx
p_strncmp_loop:
	dec rdx
	je p_strncmp_end
	mov cl,[rax]
	inc rax
	sub cl,[rbx]
	inc rbx
	je p_strncmp_loop
p_strncmp_end:
	push rcx
	next

	WORD p_find,'FIND'
	;; ( chars length -- [ chars 0 | cfa 1 )
	;; Search the current wordlists for the given pname
	pushr rsi
	mov rcx,[p_wordlist_DFA]
	mov rcx,qword [rcx]
	mov rbx,[rsp]
	mov rax,[rsp+8]
p_find_loop:
	cmp rcx,0
	je p_find_done
	cmp rbx,qword [rcx+16]	; compare lengths
	jne p_find_nextword
	push rcx
	;; check word
	push rax
	tfa2pname rcx
	push rcx
	push rbx
	DOFORTH p_strncmp
	pop rax			; return value
	pop rcx
	cmp rax,0
	je p_find_done
	mov rbx,[rsp]
	mov rax,[rsp+8]
p_find_nextword:
	mov rcx,[rcx]
	jmp p_find_loop
p_find_found:
	mov qword [rsp+8],rcx	; replace chars with tfa
	mov rcx,1
p_find_done:
	push rcx
	popr rsi
	next