forked from KolibriOS/kolibrios
Swarnadeep Paul
6de88d5fd0
- Added libunicode.asm to parse UTF-8 strings. - Implemented count_utf8_codepoints to skip continuation bytes. - Implemented count_utf8_graphemes to handle ZWJ (E2 80 8D) and combining marks (CC/CD). - Added console.asm to the examples folder to test and print the results. - Submitted for GSoC qualification task.
82 lines
1.9 KiB
NASM
82 lines
1.9 KiB
NASM
;=============================================================
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; eax <- pointer to the memory address of the string
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; * Do not use other register because it may be overwritten.
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; -------PRIVATE--------
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; ebx <- counter of codepoints
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; ecx <- each byte
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;
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;=============================================================
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count_utf8_codepoints:
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mov ebx, 0
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read_loop:
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mov cl, byte [eax]
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test cl, cl ; if it is an ending byte (0)
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je done
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and cl, 0xC0
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cmp cl, 0x80
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je skip_count
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inc ebx
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skip_count:
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inc eax
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jmp read_loop
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done:
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mov eax, ebx
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ret
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;=============================================================
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; eax <- pointer to the memory address of the string
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; * Do not use other register because it may be overwritten.
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; -------PRIVATE--------
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; ebx <- counter of grapheme
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; ecx <- each byte
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;
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;=============================================================
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count_utf8_gramphene:
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mov ebx, 0
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read_loop_graph:
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mov cl, byte [eax]
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test cl, cl ; if it is an ending byte (0)
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je done_graph
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; Is this accent
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cmp cl, 0xCC
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je skip_count_graph
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cmp cl, 0xCD
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je skip_count_graph
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; Check for not a zero width joint
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cmp cl, 0xE2
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jne not_any_special
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cmp byte [eax+1], 0x80
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jne not_any_special
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cmp byte [eax+2], 0x8D
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jne not_any_special
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dec ebx
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add eax, 3
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jmp read_loop_graph
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not_any_special:
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and cl, 0xC0 ; Is this a continution byte
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cmp cl, 0x80
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je skip_count_graph
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inc ebx
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skip_count_graph:
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inc eax
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jmp read_loop_graph
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done_graph:
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mov eax, ebx
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ret
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