basic: add ldbas command

apps/basic/README.md

@@ -82,15 +82,17 @@ are initialized to zero on launch.
 There are two types of commands: normal and direct-only. The latter can only
 be invoked in direct mode, not through a code listing.
 
-**bye**. Direct-only. Quits BASIC
+**bye**: Direct-only. Quits BASIC
 
-**list**. Direct-only. Prints all lines in the code listing, prefixing them
+**list**: Direct-only. Prints all lines in the code listing, prefixing them
 with their associated line number.
 
-**run**. Direct-only. Runs code from the listing, starting with the first one.
+**run**: Direct-only. Runs code from the listing, starting with the first one.
 If `goto` was previously called in direct mode, we start from that line instead.
 
-**print**. Prints the result of the specified expression, then CR/LF. Can be
+**clear**: Direct-only. Clears the current code listing.
+
+**print**: Prints the result of the specified expression, then CR/LF. Can be
 given multiple arguments. In that case, all arguments are printed separately
 with a space in between. For example, `print 12 13` prints `12 13<cr><lf>`
 
@@ -98,16 +100,16 @@ Unlike anywhere else, the `print` command can take a string inside a double
 quote. That string will be printed as-is. For example, `print "foo" 40+2` will
 print `foo 42`.
 
-**goto**. Make the next line to be executed the line number specified as an
+**goto**: Make the next line to be executed the line number specified as an
 argument. Errors out if line doesn't exist. Argument can be an expression. If
 invoked in direct mode, `run` must be called to actually run the line (followed
 by the next, and so on).
 
-**if**. If specified condition is true, execute the rest of the line. Otherwise,
+**if**: If specified condition is true, execute the rest of the line. Otherwise,
 do nothing. For example, `if 2>1 print 12` prints `12` and `if 2<1 print 12`
 does nothing. The argument for this command is a "thruth expression".
 
-**input**. Prompts the user for a numerical value and puts that value in the
+**input**: Prompts the user for a numerical value and puts that value in the
 specified variable. The prompted value is evaluated as an expression and then
 stored where specified. For example, `input x` stores the result of the
 evaluation in variable `x`. Before the variable name, a quoted string literal
@@ -144,3 +146,7 @@ Here's the documentation for them.
 `fs.asm` provides those commands:
 
 **fls**: prints the list of files contained in the active filesystem.
+
+**ldbas**: loads the content of the file specified in the argument (as an
+unquoted filename) and replace the current code listing with this contents. Any
+line not starting with a number is ignored (not an error).

apps/basic/buf.asm

@@ -22,6 +22,7 @@ bufInit:
 	ld	(BUF_LFREE), hl
 	ld	hl, BUF_POOL
 	ld	(BUF_PFREE), hl
+	cp	a		; ensure Z
 	ret
 
 ; Add line at (HL) with line number DE to the buffer. The string at (HL) should

apps/basic/fs.asm

@@ -1,4 +1,8 @@
 ; FS-related basic commands
+; *** Variables ***
+; Handle of the target file
+.equ	BFS_FILE_HDL	BFS_RAMSTART
+.equ	BFS_RAMEND	@+FS_HANDLE_SIZE
 
 basFLS:
 	ld	iy, .iter
@@ -9,7 +13,57 @@ basFLS:
 	call	printstr
 	jp	printcrlf
 
+
+basLDBAS:
+	call	fsFindFN
+	ret	nz
+	call	bufInit
+	ld	ix, BFS_FILE_HDL
+	call	fsOpen
+	ld	hl, 0
+	ld	de, SCRATCHPAD
+.loop:
+	ld	ix, BFS_FILE_HDL
+	call	fsGetB
+	jr	nz, .loopend
+	inc	hl
+	or	a		; null? hum, weird. same as LF
+	jr	z, .lineend
+	cp	LF
+	jr	z, .lineend
+	ld	(de), a
+	inc	de
+	jr	.loop
+.lineend:
+	; We've just finished reading a line, writing each char in the pad.
+	; Null terminate it.
+	xor	a
+	ld	(de), a
+	; Ok, line ready
+	push	hl		; --> lvl 1. current file position
+	ld	hl, SCRATCHPAD
+	call	parseDecimal
+	jr	nz, .notANumber
+	push	ix \ pop de
+	call	toSep
+	call	rdSep
+	call	bufAdd
+	pop	hl		; <-- lvl 1
+	ret	nz
+	ld	de, SCRATCHPAD
+	jr	.loop
+.notANumber:
+	pop	hl		; <-- lvl 1
+	ld	de, SCRATCHPAD
+	jr	.loop
+.loopend:
+	cp	a
+	ret
+
+
 basFSCmds:
 	.dw	basFLS
 	.db	"fls", 0, 0, 0
+	.dw	basLDBAS
+	.db	"ldbas", 0
 	.db	0xff, 0xff, 0xff	; end of table

apps/basic/main.asm

@@ -139,7 +139,7 @@ basBYE:
 
 basLIST:
 	call	bufFirst
-	ret	nz
+	jr	nz, .end
 .loop:
 	ld	e, (ix)
 	ld	d, (ix+1)
@@ -153,6 +153,7 @@ basLIST:
 	call	printcrlf
 	call	bufNext
 	jr	z, .loop
+.end:
 	cp	a		; ensure Z
 	ret
 
@@ -383,6 +384,8 @@ basCmds1:
 	.db	"list", 0, 0
 	.dw	basRUN
 	.db	"run", 0, 0, 0
+	.dw	bufInit
+	.db	"clear", 0
 ; statements
 basCmds2:
 	.dw	basPRINT

tools/emul/bshell/glue.asm

@@ -84,11 +84,10 @@
 .inc "basic/var.asm"
 .equ	BUF_RAMSTART	VAR_RAMEND
 .inc "basic/buf.asm"
-.equ	BAS_RAMSTART	BUF_RAMEND
+.equ	BFS_RAMSTART	BUF_RAMEND
-.inc "basic/main.asm"
-
-; Extra cmds
 .inc "basic/fs.asm"
+.equ	BAS_RAMSTART	BFS_RAMEND
+.inc "basic/main.asm"
 
 init:
 	di

tools/emul/cfsin/count.bas

@@ -0,0 +1,5 @@
+10 print "Count to 10"
+20 a=0
+30 a=a+1
+40 print a
+50 if a<10 goto 30