Bracket Depth Prefix Balance Tool

Description

Inspect literal bracket prefix counts without handling strings, comments or escapes.

Parsing depends on the chosen grammar, character encoding, offset unit, and treatment of escapes and delimiters. UTF-16 code-unit positions, Unicode code points, and UTF-8 byte offsets are not interchangeable. A boundary or token check supplies one part of a parser rather than validating an entire file.

Inspect literal bracket prefix counts without handling strings, comments or escapes.

When to use this tool

Use Bracket Depth Prefix Balance when you need the stated token boundary, offset, prefix, delimiter, or count component inside a larger parsing workflow.

How to use the tool and how it works

Enter prefix, opening, closing. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read balance, minimumBalance, prematureClose. Inspect prematureClose before interpreting the associated values.

Require opening and closing to be distinct strings containing exactly one Unicode code point. Scan prefix by code point, increment on opening and decrement on closing; return balance, minimumBalance, and prematureClose when any prefix balance is negative.^[1]

Input field	Meaning and units	Accepted input
prefix	Supplied text prefix; no full document context is inferred.	Required. Text; maximum UTF-16 length 8192.
opening	Exactly one Unicode code point, distinct from closing.	Required. Text; maximum UTF-16 length 8192.
closing	Exactly one Unicode code point, distinct from opening.	Required. Text; maximum UTF-16 length 8192.

Output field	Interpretation	Returned shape
balance	Balance	Required. Safe integer.
minimumBalance	Minimum Balance	Required. Safe integer.
prematureClose	Premature Close	Required. Boolean.

json

{
  "input": {
    "prefix": "(()",
    "opening": "(",
    "closing": ")"
  },
  "output": {
    "balance": 1,
    "minimumBalance": 0,
    "prematureClose": false
  }
}

Limitations and assumptions

Other characters are ignored and quote/escape context is not parsed. Final balance alone is insufficient, and this checks one bracket type rather than a full nested delimiter grammar.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.

Alternative or Complementary methods

Choose a parser for the intended complete grammar when context, nesting, encodings, or semantic validation matters. Keep byte, code-unit, and code-point coordinates explicit when combining results.

References

Calculation and input contract: parse/bracket-depth-prefix-balance — tool.io

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