# `KinoIsabelle.Positions`
[🔗](https://github.com/jcschuster/kino_isabelle/blob/v0.1.0-alpha.1/lib/kino_isabelle/positions.ex#L1)

Maps Isabelle positions to offsets in the cell text.

Isabelle reports `offset` and `end_offset` as 1-based symbol indices into the
whole theory file, `end_offset` exclusive. Symbols are delimited as by
Isabelle's `Symbol.Matcher`: `\<name>` (also when malformed, e.g. `\<abc`),
`\r\n`, or a single code point. Cell offsets are UTF-16 code units, as used by
CodeMirror. Positions inside the prepended header map to 0, positions past
the cell text (the appended `end`) map to the end of the text.

# `new`

Builds the table for `text`, preceded by `header_symbols` symbols on disk.

# `range`

Converts an Isabelle position map to `{from, to}`.

A missing or empty `end_offset` extends the range to one symbol; a missing
position yields `{0, 0}`.

# `symbol_count`

Number of Isabelle symbols in `text`.

# `utf16_offset`

Converts a byte offset in `text` to a UTF-16 offset.

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*Consult [api-reference.md](api-reference.md) for complete listing*