small cleanup in BASIC

src/basic/editor/delete_line.s

@@ -2,14 +2,12 @@
 // #LAYOUT# *   BASIC_0 #TAKE
 // #LAYOUT# *   *       #IGNORE
 
-// Delete the current BASIC line, which is assumed to have already
+//
-// been found with find_line.
+// Delete the current BASIC line, which is assumed to have already been found with find_line.
-// Really only consists of copying memory down.
+// Consists of copying memory down and lline linkage update.
-// The only complication is that we have to do the copy with ROMs
+//
-// banked out. Oh, yes, and we have to update all the links in
-// the following basic lines.
 
-basic_delete_line:
+delete_line:
 
 	// jsr printf
 	// .text "DELETING LINE AT $"
@@ -61,6 +59,7 @@ basic_delete_line:
 	sbc #0
 	cmp #$00
 	beq !+
+
 	// Line length is <0 or >255 bytes.
 	// Either way, things are bad, so abort.
 	jmp do_MEMORY_CORRUPT_error

src/basic/editor/insert_line.s

@@ -2,17 +2,18 @@
 // #LAYOUT# *   BASIC_0 #TAKE
 // #LAYOUT# *   *       #IGNORE
 
+//
 // Insert the tokenised line stored at $0200.
-// First work out where in the list to put it
+//
-// (basic_find_line with the line number can be used to work
+// First work out where in the list to put it (find_line with the line number can be used to work
-// out the insertion point, as it should abort once it finds a
+// out the insertion point, as it should abort once it finds a line number too high).
-// line number too high).
 // Then all we have to do is push the rest of the BASIC text up,
 // and update the pointers in all following basic lines.
+//
 
-basic_insert_line:
+insert_line:
 
-	// ASSUMES basic_find_line has been called to set the insert point.
+	// ASSUMES find_line has been called to set the insert point.
 	// We need to insert space for the link link token, the line number,
 	// and the zero-terminated line itself.  This means 2+2+1 plus length
 	// of tokenised string after the line number
@@ -36,6 +37,7 @@ basic_insert_line:
 	lda __tokenise_work2
 	sec
 	sbc __tokenise_work1
+
 	// Add on the four bytes space we need
 	clc
 	adc #5
@@ -82,7 +84,7 @@ basic_insert_line:
 
 	// Now store the line body itself
 	inc __tokenise_work2
-line_store_loop:
+!:
 	ldx __tokenise_work1
 	lda $0200,x
 	inc __tokenise_work1
@@ -97,7 +99,7 @@ line_store_loop:
 
 	lda __tokenise_work1
 	cmp __tokenise_work2
-	bne line_store_loop
+	bne !-
 	dec __tokenise_work2
 	
 	clc

src/basic/editor/shell.s

@@ -148,24 +148,22 @@ shell_add_delete_line:
 
 	// First, clear all variables, so that we only have to shove BASIC text around
 	jsr basic_do_clr
-.break
+
-	// Delete line if present
+	// Check if line already present
 	jsr find_line
-
-// XXX
-
 	bcs !+
 
-	// Delete the line, whether we are deleting or
+	// Line already present - delete it
-	// replacing the line
+.break
-	jsr basic_delete_line
+	jsr delete_line
+
 !:
 	// Insert new line if non-zero length, i.e., that
 	// we are not just deleting the line.
 	lda __tokenise_work1
 	cmp __tokenise_work2
 	beq !+
-	jsr basic_insert_line
+	jsr insert_line
 !:
 	// No READY message after entering or deleting a line of BASIC
 	jmp shell_read_next_line