Description
Require whole index in [0,90] and return its symbol in the implementation's ordered basE91 alphabet, beginning uppercase letters, lowercase letters and decimal digits, followed by its punctuation sequence.
A positional encoding separates numeric digit values, alphabet symbols and final-block padding. An alphabet lookup is not a whole-stream codec, and character count can differ from the number of source bytes represented.
Require whole index in [0,90] and return its symbol in the implementation's ordered basE91 alphabet, beginning uppercase letters, lowercase letters and decimal digits, followed by its punctuation sequence.
When to use this tool
Use Base91 Alphabet Index Symbol when checking one alphabet mapping or bounded encoding-padding term.
How to use the tool and how it works
- Enter index. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read symbol. Use the output convention below.
Require whole index in [0,90] and return its symbol in the implementation's ordered basE91 alphabet, beginning uppercase letters, lowercase letters and decimal digits, followed by its punctuation sequence.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| index | Index | Required. Safe integer; minimum 0; maximum 90. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| symbol | Symbol | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"index": 0
},
"output": {
"symbol": "A"
}
}Limitations and assumptions
- This is one specific alphabet lookup, not a complete basE91 codec or a guarantee that another Base91 variant uses the same order.
- 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.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete codec matching the intended alphabet and padding policy for real payloads and interoperability checks.
References
Similar or alternative tools
- Encoding: Base64 Alphabet Value Symbol
Return the indexed symbol from A-Z, a-z, 0-9 followed by +/ for standard or -_ for url.
- Base58 Alphabet Value Symbol
Return the symbol in the Bitcoin-style Base58 alphabet 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz.