PARSE: TO and THRU multiple
A84 provides a first draft implementation of the TO and THRU commands that will match multiple targets.
For example, to match CR, LF, or END in a string, you can write:
to [cr | lf | end]
Main rules:
- For blocks, you can match a single input value. Use QUOTE for special literals.
- For strings, the match can be made with a string, char, or integer char value. The match is case-insensitive unless the /case refinement is used.
- For binary, the match can be made with binary!, integer byte value (lowest 8 bits of the integer), or char value (less than 256.)
- Each target can be followed with a paren for taking action on the match. (Allows you to set a variable if you need to know which target you hit.)
A few special notes:
- Do not forget the or-bar to separate the targets.
- Only singular match rules are supported at this time. Do not use complex rules.
- Can be very CPU intensive. Don't use string targets where char targets are wanted (e.g. use #"a" not "a" when possible.) Also be aware that using variables for targets will slow it down. (No target caching as of yet.)
- You cannot mix string and binary types. Remember that strings are Unicode-oriented and binary is encoded data (such as UTF-8 or anything else.)
Example:
This code removes all CRs and LFs from the string:
parse str [any [to [cr | lf] remove skip]]
Count the number of CR and LF chars in a string and display them:
cr's: lf's: 0
parse str [any [thru [cr (++ cr's) | lf (++ lf's)]]]
?? [cr's lf's]
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