Description
Find a literal common space/tab prefix without expanding tabs or excluding blank lines.
Text positions can be measured in UTF-16 code units, Unicode code points, grapheme clusters, or modeled display columns. These coordinates are not interchangeable. Invisible markers and delimiter policies can also affect interpretation even when a string looks unchanged, so the chosen representation needs to stay explicit.
Find a literal common space/tab prefix without expanding tabs or excluding blank lines.
When to use this tool
Use Line Prefix Common Indent when you need the stated marker, coordinate, delimiter, or normalization operation under an explicit text representation.
How to use the tool and how it works
- Enter lines. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read commonIndent, units. Use the output convention below.
Extract leading ASCII spaces and tabs from each line in a nonempty list, then return their longest identical literal prefix and its UTF-16 length as units.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| lines | Lines | Required. Array of text; maximum UTF-16 length 8192; maximum items 256. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| commonIndent | Common Indent | Required. Text; maximum UTF-16 length 8192. |
| units | Literal common indentation length, not equivalent display columns. | Required. Safe integer. |
{
"input": {
"lines": [
" a",
" b"
]
},
"output": {
"commonIndent": " ",
"units": 2
}
}Limitations and assumptions
- Tabs and spaces are distinct characters rather than equivalent display columns. Empty or unindented lines can reduce the common prefix to empty; no lines are dedented.
- The field tables state structural bounds; the mechanics also specify cross-field constraints. Malformed inputs and unsupported domains cause errors. A successful false flag, empty branch value, or zero placeholder has the meaning stated above and is distinct from an input error.
Alternative or Complementary methods
Choose the coordinate system required by the consumer. Use a full parser, renderer, or segmentation method when a local marker or delimiter rule cannot determine the complete text behavior.
References
Similar or alternative tools
- Line Break CRLF Byte Budget
Count CRLF pairs and remaining lone LF characters, returning bytesAdded equal to lone LF count under a conversion to CRLF.
- String Prefix Collision Sentinel Choice
Start sentinel at a nonempty prefix and append underscores until no values entry starts with it.