kyleandClaude Opus 5.5
cfde35397a
docs/plans/p5a: 01 kind+fetch limits, 02 pdftext child + runner, 03 dcache PDF tables, 04 pdfpool, 05 pdfdoc render (map/pages/grep), 06 api, 07 digest citations, metrics, CLI, skill, unit, README. Given tests compile against a panic-only skeleton and fail there for the intended reasons; PDFs for tests are built by internal/pdftest (given), plus two qpdf-encrypted fixtures. Owner changes for the run: vendor go-pdfkit/extract v0.3.0 + reader v0.6.0 (pinned via tools.go until task 02); AGENTS.md, tools/run-plan.sh (enforces a Co-Authored-By trailer for the model), docs/implementer-log.md, `make gate`; gofmt (whitespace) on clean.go and guard; TestUnsupportedType uses a zip now that PDFs are supported; requestDeadline 90→210 s and writeTimeout 120→240 s for the PDF path's worst case. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
76 lines
3.6 KiB
Markdown
76 lines
3.6 KiB
Markdown
# pdffont
|
|
|
|
[](https://github.com/go-pdfkit/pdffont/actions/workflows/ci.yml)
|
|
[](https://pkg.go.dev/github.com/go-pdfkit/pdffont)
|
|
[](LICENSE)
|
|
[](#how-it-is-checked)
|
|
|
|
The PDF side of a font: not the outlines, which are the font program's
|
|
business, but everything the document itself says about how a string of
|
|
bytes is to be read.
|
|
|
|
Which codes a string holds, how wide each one is, what each is called, and
|
|
what text each stands for. It is what a renderer needs before it can ask a
|
|
font program for a glyph, and all an extractor needs to read a page back as
|
|
words — so neither has to say it twice.
|
|
|
|
Pure Go, no C, nothing outside [`reader`](https://github.com/go-pdfkit/reader)
|
|
and the standard library.
|
|
|
|
## What it reads
|
|
|
|
Simple fonts, addressed one byte at a time through a base encoding and
|
|
whatever differences the document names on top of it. Composite fonts,
|
|
addressed by character identifier, with their widths and their map from
|
|
identifier to glyph. Type 3 fonts, whose glyphs are little drawings and
|
|
whose widths are in a space of their own.
|
|
|
|
And `/ToUnicode`, which is the one thing in a PDF that says what its text
|
|
actually **says**. Without it a page can be drawn but not read.
|
|
|
|
## What it refuses to guess
|
|
|
|
A font that says it is **symbolic** is addressed through its own character
|
|
map, and a base encoding is a guess at it — a bad one. A mathematical font
|
|
puts a capital gamma where the standard encoding puts an inverted
|
|
exclamation mark, so reading the name gives the wrong letter with nothing
|
|
to say so.
|
|
|
|
Such a code is left unread unless the document named it itself, or unless a
|
|
caller installs [`Font.SetFallback`](https://pkg.go.dev/github.com/go-pdfkit/pdffont#Font.SetFallback)
|
|
to say what the embedded program calls it. Reading the program is another
|
|
package's work; `extract` does it with
|
|
[`go-opentype`](https://github.com/go-opentype/opentype).
|
|
|
|
## How it is checked
|
|
|
|
100% of statements, including every branch that handles a dictionary saying
|
|
something it should not.
|
|
|
|
And the glyph-name table — which is the one piece of data here, and where a
|
|
single wrong entry would silently give the wrong letter — is held up
|
|
against the documents themselves. A font that both names a code and carries
|
|
a `/ToUnicode` entry for it states the same fact twice, so the two can be
|
|
compared. Over 12 000 corpus files: **63 515 names checked, 63 074 agreed —
|
|
99.31%**. The disagreements are producers whose own maps are wrong
|
|
(`alpha` → `↵`, `ff` → `!`), plus `Delta` and `Omega`, which Adobe's list
|
|
gives as the increment and ohm signs; the Greek letters written here are
|
|
the same characters by Unicode's own equivalence, and the ones a person
|
|
searching would type.
|
|
|
|
## The rest of the family
|
|
|
|
[**reader**](https://github.com/go-pdfkit/reader) reads and writes the format ·
|
|
[**ops**](https://github.com/go-pdfkit/ops) is the verbs and the `pdfops` command ·
|
|
[**render**](https://github.com/go-pdfkit/render) turns a page into pixels ·
|
|
[**pdffont**](https://github.com/go-pdfkit/pdffont) is what a document says about a font ·
|
|
[**extract**](https://github.com/go-pdfkit/extract) reads a page back ·
|
|
[**coedit**](https://github.com/go-pdfkit/coedit) is a PDF several people edit at once ·
|
|
[**app**](https://github.com/go-pdfkit/app) is the browser workbench.
|
|
|
|
Documentation for all of it: <https://go-pdfkit.github.io/docs/>
|
|
|
|
## Licence
|
|
|
|
BSD-3-Clause.
|