| 1 | # Pretty printing "documents". A `doc` encodes printing instructions, including
|
| 2 | # choices between multiple possible layouts.
|
| 3 |
|
| 4 | module pretty
|
| 5 | {
|
| 6 | # A pretty printing document, together with a measure of its size.
|
| 7 | MeasuredDoc = (doc doc, Measure measure)
|
| 8 |
|
| 9 | # The "size" of a document:
|
| 10 | # - `flat` gives the width of the doc if printed flat (on one line).
|
| 11 | # - `nonflat` gives the width until the doc's first possible newline,
|
| 12 | # or -1 if no layout of the doc contains a newline.
|
| 13 | Measure = (int flat, int nonflat)
|
| 14 |
|
| 15 | # Leaf Value optimization
|
| 16 | # This affects:
|
| 17 | # the GC mask for any struct that contains it
|
| 18 | # C++ uses parent.measure instead of parent->measure
|
| 19 | #Measure_v = (int flat, int nonflat)
|
| 20 |
|
| 21 | List_Measured < List[MeasuredDoc]
|
| 22 |
|
| 23 | # A pretty printing "document", which encodes a set of possible layouts.
|
| 24 | # The pretty printer will pick the "best" layout from among this set.
|
| 25 | # See the docs on the constructors in `pretty.py` for details.
|
| 26 | doc =
|
| 27 | Break(str string)
|
| 28 | | Text(str string)
|
| 29 | | Indent(int indent, MeasuredDoc mdoc)
|
| 30 | | Group %MeasuredDoc
|
| 31 | | Flat(MeasuredDoc mdoc)
|
| 32 | | IfFlat(MeasuredDoc flat_mdoc, MeasuredDoc nonflat_mdoc)
|
| 33 | | Concat %List_Measured
|
| 34 |
|
| 35 | # Optimizing allocations
|
| 36 | # - Concat can be a List subtype
|
| 37 | # - One of Break or Text can be %Str, when we add it
|
| 38 | # - All these objects are immutable, so there can be a lot of sharing / hash consing, etc.
|
| 39 | # - especially for ( : , ) '' etc. and ANSI styles
|
| 40 |
|
| 41 | # Used internally while pretty printing.
|
| 42 | # See comments in PrettyPrinter._PrintDoc.
|
| 43 | DocFragment = (MeasuredDoc mdoc, int indent, bool is_flat, Measure measure)
|
| 44 | }
|