ed: add support for 'a' and 'i'

apps/ed/README.md

@@ -10,11 +10,15 @@ mostly a repeat of `Ued`'s man page.
 ## Differences
 
 There are a couple of differences with `Ued` that are intentional. Differences
-not listed here are either bugs or simply arent implemented yet.
+not listed here are either bugs or simply aren't implemented yet.
 
 * Always has a prompt, `:`.
 * No size printing on load
 * Initial line is the first one
+* Line input is for one line at once. Less scriptable for `Ued`, but we can't
+  script `ed` in Collapse OS anyway...
+* For the sake of code simplicity, some commands that make no sense are
+  accepted. For example, `1,2a` is the same as `2a`.
 
 ## Usage
 
@@ -32,6 +36,8 @@ range is out of bounds.
 * `(addrs)p`: Print lines specified in `addrs` range. This is the default
   command. If only `(addrs)` is specified, it has the same effect.
 * `(addrs)d`: Delete lines specified in `addrs` range.
+* `(addr)a`: Appends a line after `addr`.
+* `(addr)i`: Insert a line before `addr`.
 * `q`: quit `ed`
 
 ### Current line
@@ -41,7 +47,7 @@ to it and makes the app much more usable. The current line starts at `1` and
 every command changes the current line to the last line that the command
 affects. For example, `42p` changes the current line to `42`, `3,7d`, to 7.
 
-### Address ranges
+### Addresses
 
 An "address" is a line number. The first line is `1`. An address range is a
 start line and a stop line, expressed as `start,stop`. For example, `2,4` refer

apps/ed/buf.asm

@@ -3,24 +3,30 @@
 ; Lines in edited file aren't loaded in memory, their offsets is referenced to
 ; in this buffer.
 ;
+; About scratchpad and offsets. There are two scratchpads: file and memory.
+; The file one is the contents of the active blkdev. The second one is
+; in-memory, for edits. We differentiate between the two with a
+; "scatchpad mask". When the high bits of the offset match the mask, then we
+; know that this offset is from the scratchpad.
+;
 ; *** Consts ***
 ;
 ; Maximum number of lines allowed in the buffer.
 .equ	BUF_MAXLINES	0x800
 ; Size of our scratchpad
 .equ	BUF_PADMAXLEN	0x1000
+; Scratchpad mask (only applies on high byte)
+.equ	BUF_SCRATCHPAD_MASK	0b11110000
 
 ; *** Variables ***
 ; Number of lines currently in the buffer
 .equ	BUF_LINECNT	BUF_RAMSTART
 ; List of words pointing to scratchpad offsets
 .equ	BUF_LINES	BUF_LINECNT+2
-; size of file we read in bufInit. That offset is the beginning of our
-; in-memory scratchpad.
-.equ	BUF_FSIZE	BUF_LINES+BUF_MAXLINES*2
+; Points to the end of the scratchpad
+.equ	BUF_PADEND	BUF_LINES+BUF_MAXLINES*2
 ; The in-memory scratchpad
-.equ	BUF_PADLEN	BUF_FSIZE+2
-.equ	BUF_PAD		BUF_PADLEN+2
+.equ	BUF_PAD		BUF_PADEND+2
 
 .equ	BUF_RAMEND	BUF_PAD+BUF_PADMAXLEN
 
@@ -29,8 +35,8 @@
 ; On initialization, we read the whole contents of target blkdev and add lines
 ; as we go.
 bufInit:
-	ld	hl, 0
-	ld	(BUF_PADLEN), hl
+	ld	hl, BUF_PAD
+	ld	(BUF_PADEND), hl
 	ld	ix, BUF_LINES
 	ld	bc, 0		; line count
 .loop:
@@ -45,8 +51,6 @@ bufInit:
 	call	ioGetLine
 	jr	.loop
 .loopend:
-	; HL currently has the result of the last blkTell
-	ld	(BUF_FSIZE), hl
 	ld	(BUF_LINECNT), bc
 	ret
 
@@ -76,10 +80,27 @@ bufGetLine:
 	ld	d, (hl)
 	; DE has seek offset
 	ex	de, hl
-	; and now HL has it. We're ready to call ioGetLine!
 	pop	de
+	; is it a scratchpad offset?
+	ld	a, h
+	and	BUF_SCRATCHPAD_MASK
+	cp	BUF_SCRATCHPAD_MASK
+	jr	z, .fromScratchpad
+	; not from scratchpad
 	cp	a	; ensure Z
 	jp	ioGetLine	; preserves AF
+.fromScratchpad:
+	; remove scratchpad mask
+	ld	a, BUF_SCRATCHPAD_MASK
+	xor	0xff
+	and	h
+	ld	h, a
+	; HL is now a mask-less offset to BUF_PAD
+	push	de	; --> lvl 1
+	ld	de, BUF_PAD
+	add	hl, de
+	pop	de	; <-- lvl 1
+	ret
 .outOfBounds:
 	pop	de
 	jp	unsetZ
@@ -125,3 +146,63 @@ bufDelLines:
 	; Both HL and DE are translated. Go!
 	ldir
 	ret
+
+; Insert string where DE points to memory scratchpad, then insert that line
+; at index HL, offsetting all lines by 2 bytes.
+bufInsertLine:
+	push	de	; --> lvl 1, scratchpad offset
+	push	hl	; --> lvl 2, insert index
+	; The logic below is mostly copy-pasted from bufDelLines, but with a
+	; LDDR logic (to avoid overwriting). I learned, with some pain involved,
+	; that generalizing this code wasn't working very well. I don't repeat
+	; the comments, refer to bufDelLines
+	ex	de, hl	; line index now in DE
+	ld	hl, (BUF_LINECNT)
+	scf \ ccf
+	sbc	hl, de
+	; mult by 2 and we're done
+	sla	l \ rl h
+	push	hl \ pop bc
+	; From this point, we don't need our line index in DE any more because
+	; LDDR will start from BUF_LINECNT-1 with count BC. We'll only need it
+	; when it's time to insert the line in the space we make.
+	ld	hl, (BUF_LINECNT)
+	call	bufLineAddr
+	push	hl \ pop	de
+	dec	hl
+	dec	hl
+	; HL = BUF_LINECNT-1, DE = BUF_LINECNT, BC is set. We're good!
+	lddr
+	; We still need to increase BUF_LINECNT
+	ld	hl, (BUF_LINECNT)
+	inc	hl
+	ld	(BUF_LINECNT), hl
+	; A space has been opened at line index HL. Let's fill it with our
+	; inserted line.
+	pop	hl		; <-- lvl 2, insert index
+	call	bufLineAddr
+	pop	de		; <-- lvl 1, scratchpad offset
+	ld	(hl), e
+	inc	hl
+	ld	(hl), d
+	ret
+
+; copy string that HL points to to scratchpad and return its seek offset, in HL.
+bufScratchpadAdd:
+	push	de
+	ld	de, (BUF_PADEND)
+	push	de	; --> lvl 1
+	call	strcpyM
+	ld	(BUF_PADEND), de
+	pop	hl	; <-- lvl 1
+	; we have a memory offset in HL, but it's not what we want! we want a
+	; seek offset stamped with the "scratchpad mask"
+	ld	de, BUF_PAD
+	scf \ ccf
+	sbc	hl, de
+	ld	a, h
+	or	BUF_SCRATCHPAD_MASK
+	ld	h, a
+	; now we're good...
+	pop	de
+	ret

apps/ed/cmd.asm

@@ -55,6 +55,10 @@ cmdParse:
 	jr	z, .okCmd
 	cp	'd'
 	jr	z, .okCmd
+	cp	'a'
+	jr	z, .okCmd
+	cp	'i'
+	jr	z, .okCmd
 	; unsupported cmd
 	ret			; Z unset
 .nullCmd:

apps/ed/glue.asm

@@ -4,6 +4,7 @@
 
 	jp	edMain
 
+#include "lib/util.asm"
 #include "lib/parse.asm"
 .equ	IO_RAMSTART	USER_RAMSTART
 #include "ed/io.asm"

apps/ed/main.asm

@@ -39,9 +39,8 @@
 ; intoHL
 ; printstr
 ; printcrlf
-; stdioGetLine
+; stdioReadLine
 ; stdioPutC
-; stdioReadC
 ; unsetZ
 ;
 ; *** Variables ***
@@ -59,19 +58,24 @@ edMain:
 .mainLoop:
 	ld	a, ':'
 	call	stdioPutC
-.inner:
-	call	stdioReadC
-	jr	nz, .inner	; not done? loop
-	; We're done. Process line.
+	call	stdioReadLine	; --> HL
+	; Now, process line.
 	call	printcrlf
-	call	stdioGetLine
 	call	cmdParse
 	jr	nz, .error
 	ld	a, (CMD_TYPE)
 	cp	'q'
 	jr	z, .doQuit
+	; The rest of the commands need an address
+	call	edReadAddrs
+	jr	nz, .error
+	ld	a, (CMD_TYPE)
 	cp	'd'
 	jr	z, .doDel
+	cp	'a'
+	jr	z, .doAppend
+	cp	'i'
+	jr	z, .doInsert
 	jr	.doPrint
 
 .doQuit:
@@ -79,16 +83,22 @@ edMain:
 	ret
 
 .doDel:
-	call	edReadAddrs
-	jr	nz, .error
 	; bufDelLines expects an exclusive upper bound, which is why we inc DE.
 	inc	de
 	call	bufDelLines
 	jr	.mainLoop
+.doAppend:
+	inc	de
+.doInsert:
+	call	stdioReadLine	; --> HL
+	call	bufScratchpadAdd	; --> HL
+	; insert index in DE, line offset in HL. We want the opposite.
+	ex	de, hl
+	call	bufInsertLine
+	call	printcrlf
+	jr	.mainLoop
+
 .doPrint:
-	call	edReadAddrs
-	jr	nz, .error
-.doPrintLoop:
 	push	hl
 	call	bufGetLine
 	jr	nz, .error
@@ -98,7 +108,7 @@ edMain:
 	call	cpHLDE
 	jr	z, .doPrintEnd
 	inc	hl
-	jr	.doPrintLoop
+	jr	.doPrint
 .doPrintEnd:
 	ld	(ED_CURLINE), hl
 	jr	.mainLoop

apps/lib/util.asm

@@ -0,0 +1,21 @@
+; Copy string from (HL) in (DE), that is, copy bytes until a null char is
+; encountered. The null char is also copied.
+; HL and DE point to the char right after the null char.
+strcpyM:
+	ld	a, (hl)
+	ld	(de), a
+	inc	hl
+	inc	de
+	or	a
+	jr	nz, strcpyM
+	ret
+
+; Like strcpyM, but preserve HL and DE
+strcpy:
+	push	hl
+	push	de
+	call	strcpyM
+	pop	de
+	pop	hl
+	ret
+

apps/zasm/glue.asm

@@ -53,6 +53,7 @@
 jp	zasmMain
 
 #include "zasm/const.asm"
+#include "lib/util.asm"
 #include "zasm/util.asm"
 .equ	IO_RAMSTART	USER_RAMSTART
 #include "zasm/io.asm"

apps/zasm/util.asm

@@ -107,27 +107,6 @@ strcmp:
 	; early, set otherwise)
 	ret
 
-; Copy string from (HL) in (DE), that is, copy bytes until a null char is
-; encountered. The null char is also copied.
-; HL and DE point to the char right after the null char.
-strcpyM:
-	ld	a, (hl)
-	ld	(de), a
-	inc	hl
-	inc	de
-	or	a
-	jr	nz, strcpyM
-	ret
-
-; Like strcpyM, but preserve HL and DE
-strcpy:
-	push	hl
-	push	de
-	call	strcpyM
-	pop	de
-	pop	hl
-	ret
-
 ; If string at (HL) starts with ( and ends with ), "enter" into the parens
 ; (advance HL and put a null char at the end of the string) and set Z.
 ; Otherwise, do nothing and reset Z.

kernel/stdio.asm

@@ -202,3 +202,12 @@ stdioReadC:
 stdioGetLine:
 	ld	hl, STDIO_BUF
 	ret
+
+; Repeatedly call stdioReadC until Z is set, then make HL point to the read
+; buffer.
+stdioReadLine:
+	call	stdioReadC
+	jr	nz, stdioReadLine
+	ld	hl, STDIO_BUF
+	ret
+

tools/emul/shell/shell_.asm

@@ -36,8 +36,7 @@
 	jp	_blkTell
 	jp	printcrlf
 	jp	stdioPutC
-	jp	stdioReadC
-	jp	stdioGetLine
+	jp	stdioReadLine
 	jp	blkGetC
 	jp	blkSeek
 	jp	blkTell

tools/emul/shell/user.h

@@ -29,8 +29,7 @@
 .equ	_blkTell		0x45
 .equ	printcrlf		0x48
 .equ	stdioPutC		0x4b
-.equ	stdioReadC		0x4e
-.equ	stdioGetLine	0x51
-.equ	blkGetC			0x54
-.equ	blkSeek			0x57
-.equ	blkTell			0x5a
+.equ	stdioReadLine	0x4e
+.equ	blkGetC			0x51
+.equ	blkSeek			0x54
+.equ	blkTell			0x57