Issue 30

[Mingun]

Sorry fo my english, I hope, that it is not so bad...

I realize issue #30 -- feature for specify exact count an min-max range of repetitions of rule, optionally delimited by delimiter rule/expression. Delimiter not included in result. Syntax (, delimiter may be omitted):

expression |exact, delimiter|
expression |min.., delimiter|
expression |..max, delimiter|
expression |min..max, delimiter|
expression |.., delimiter|

Now all constraints -- a int in grammar, but bytecode not limited by this.

I add 2 opcodes to abstract VM: IF_ARRLEN_MIN and IF_ARRLEN_MAX.

New IF... opcodes use stack to get constraint and array and compiled to:

min = stack.pop();
if (typeof(min) !== "undefined" && stack.top().length < min) {
  <then code>
} else {
  <else code>
}

max = stack.pop();
if (typeof(max) !== "undefined" && stack.top().length >= max) {
  <then code>
} else {
  <else code>
}

[lavelle]

What's blocking this? Would be great to see it merged.

[Mingun]

@dmajda , what you think about this? Now also included testcases and, I think, it may be merged...

[dmajda]

What's blocking this? Would be great to see it merged.

@lavelle This is a pull request for a feature I clearly labeled as post-1.0.0, so it wasn't a high priority for me.

Now also included testcases and, I think, it may be merged...

@Mingun Sorry, I won't merge this, for several reasons:

• Syntax discussion in Ability to specify repetition count (like in regexps) #30 hasn't been concluded yet. There is no way I'm merging code for a feature before finishing its design.
• The implemented syntax deviates from proposals in Ability to specify repetition count (like in regexps) #30, in particular the ones I was considering. There is no obvious reason for this.
• The pull request does something else beside fixing Ability to specify repetition count (like in regexps) #30, namely it adds a delimiter handing. This is entirely separate topic and discussion (which already happens elsewhere).
• The pull request is a mess. Commits fixing things in previous commits, rebases/updates, etc. I want PEG.js Git history to be clean.