From 0ac65464902ff2e2076a19b1ef879fef8f5ac961 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Wed, 23 Feb 2022 03:00:03 +0200
Subject: [PATCH] Check dictionary for word

---
 compress-dict.py |   2 +-
 dosdl.asm        | 106 ++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 105 insertions(+), 3 deletions(-)

diff --git a/compress-dict.py b/compress-dict.py
index d54a741..1ff9a68 100644
--- a/compress-dict.py
+++ b/compress-dict.py
@@ -33,4 +33,4 @@ with open(targetpath, 'w') as f:
 
 	f.write('dictionaries:\n')
 	for startletter in arrays:
-		f.write(f'\tdw dictionary_{startletter}\n')
+		f.write(f'\tdw dictionary_{startletter}, {len(arrays[startletter])}\n')
diff --git a/dosdl.asm b/dosdl.asm
index e433f12..b197e40 100644
--- a/dosdl.asm
+++ b/dosdl.asm
@@ -113,8 +113,104 @@ read_guess:
 
 	.done:
 
-check_guess:
-	; TODO: See whether guess is in the dictionary or targets
+check_dictionary:
+	; Dictionary is split by initial letter
+	xor bx, bx
+	mov bl, [guess]
+	sub bl, 'a'
+
+	; Entry in the table is 4 bytes
+	shl bx, 1
+	shl bx, 1
+	mov si, [dictionaries + bx] ; Start address
+	mov cx, [dictionaries + bx + 2] ; Number of letters
+
+	.dictionary_loop:
+		push cx
+
+		mov di, dictionary_entry
+		; Entry is stored 5 bits per letter (first letter is implicit)
+		; 3332_2222 5444_4433 0000_5555
+		; Load 5444_4433_3332_2222 into dx and extract 3 first letters
+		mov dx, [si]
+		add si, 2
+		mov cl, 5
+%rep 3
+		mov al, dl
+		and al, 0x1f
+		add al, 'a'
+		stosb
+		shr dx, cl
+%endrep
+		; Load 0000_5555 into al, shift one over, or with dl which has
+		; 0000_0005
+		mov al, [si]
+		inc si
+		shl al, 1
+		or al, dl
+		add al, 'a'
+		stosb
+
+		sub di, 4
+		mov bp, 1
+		mov cx, 4
+		.compare_loop:
+			mov al, [di]
+			inc di
+			cmp al, [guess + bp]
+			jne .not_match
+			inc bp
+			loop .compare_loop
+
+		pop cx
+		jmp word_found
+
+		.not_match:
+		pop cx
+		loop .dictionary_loop
+
+check_targets:
+	; TODO: Check whether word is in the list of target words
+
+word_not_found:
+	mov ah, 9
+	mov dx, not_found_str
+	int 0x21
+
+	; Wait for a keypress
+	mov ah, 8
+	int 0x21
+
+	; Clear line
+	mov ah, 2
+	mov dl, 13
+	int 0x21
+
+	mov ah, 9
+	mov dx, erase_word_str
+	int 0x21
+
+	mov si, not_found_str
+	.clear_loop:
+		lodsb
+		cmp al, '$'
+		je .done
+
+		mov ah, 2
+		mov dl, ' '
+		int 0x21
+
+		jmp .clear_loop
+
+	.done:
+
+	mov ah, 2
+	mov dl, 13
+	int 0x21
+
+	jmp read_guess
+
+word_found:
 
 find_exact_hits:
 	mov si, guess
@@ -292,12 +388,18 @@ newline:
 section .data
 target times 5 db 0
 guess times 5 db 0
+
 exact_hits times 5 db 0
 wrong_places times 5 db 0
+
 guesses db 0
 
+dictionary_entry times 4 db 0
+
 section .rodata
 
+not_found_str db ' - word not found$'
+erase_word_str db '     $'
 word_was_str db 'The word was: $'
 correct_in_str db 'Correct in $'
 guesses_str db ' guesses.$'