From 9ffc3b667847aee0557cc3c020f3764524f9339d Mon Sep 17 00:00:00 2001
From: kitty <nepeta@canaglie.net>
Date: Mon, 16 Mar 2026 12:22:09 +1100
Subject: `find`

---
 sanctuary.s | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 53 insertions(+), 2 deletions(-)

(limited to 'sanctuary.s')

diff --git a/sanctuary.s b/sanctuary.s
index 2db3bc8..18c6623 100644
--- a/sanctuary.s
+++ b/sanctuary.s
@@ -40,6 +40,13 @@
 %endmacro
 ; }}}
 
+%assign smudge_mask	0x1
+%assign immediate_mask	0x2
+%assign comp_only_mask	0x4
+
+%assign true 0x0
+%assign false (~0x0)
+
 %assign INTERPRET 0x0
 %assign COMPILING (~0x0)
 
@@ -68,8 +75,6 @@ _start:
 	call type
 	call bye
 
-teststr: db "TESTING"
-
 defcode "brk@", brk@, 0
 	xor rdi, rdi
 	mov rax, __NR_brk
@@ -225,6 +230,52 @@ defcode "type", type, 0
 	syscall
 	ret
 
+; r9:  processing temporary value
+; r10: input size
+; r11: input addr
+; r12: pointer into currently processing word
+; r13: same as r12 but kept at xt
+defcode "find", find, 0
+	pspop r10 ; u
+	pspop r11 ; a
+	mov r12, qword [latest]
+	mov r13, r12
+
+.check_smudge:
+	add r12, 8
+	mov r9b, byte [r12]
+	test r9b, smudge_mask
+	jnz .no
+
+	inc r12
+	mov r9b, byte [r12]
+	cmp r9b, r10b
+	jne .no
+
+	mov rsi, r12
+	inc rsi
+	mov rdi, r11
+	mov rcx, r10
+	repe cmpsb
+	jnz .no
+
+	pspush r13
+	mov r13, true
+	pspush r13
+	ret
+
+.no:
+	mov r12, qword [r13]
+	mov r13, r12
+	cmp r12, 0
+	jne .check_smudge
+
+	pspush r11
+	pspush r10
+	mov r13, false
+	pspush r13
+	ret
+
 ; .s {{{
 defcode ".s", dots, 0
 	push r11
-- 
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