The BBC and Master Computer Public Domain Library

ACF8 Extract next field

Submitted by Steve Fewell

Description:

This routine gets the next field from an input (or data) line. The field value is returned as a string in the SWA

First, get the next non-space character and set Y to point to this character.
If the character is a double quote ("), then we have found a String value, so call routine AD19 to extract the String,
place the value of the String (without the surrounding quotes) in the SWA and update BASIC Text Pointer B Offset to
point to after the String value.

Keep getting the next character from BASIC Text Pointer B (Starting at Y) and store the character in the next free
SWA location (starting at &0600 - uses X as an index), until the character is a carriage return <cr>, or a comma ','.

Decrement Y and X (so that they point to the <cr> or ',' character), store X in &36 (the length of the field
excluding the <cr> or ',' character), and store Y in &1B (so that PTR B points to the <cr> or ',' character).

Set A to 00 (as return type is a String), and exit.

Disassembly for the Extract next field routine