The parser works on raw byte sequences read from source files. If parsing
succeeds the raw byte sequences are converted to proper Unicode characters
in a later phase. But the parser calls the function buildAnyTree, which can
fail and generate error messages containing source code fragments, which might
then containing raw byte sequences. To render these error messages correctly,
they need to be converted in accordance with the coding flag in the source
file. This is now done for UTF-8-encoded source files, but should ideally also
be done for other character encodings. (Latin-1-encoded files never suffered
from this problem, since raw bytes are proper Unicode characters in this case.)
+ Instead of "Internal error in ...", you now get a proper error message with
a source location and a function name.
+ Also added some missing error value propagation in the partial evaluator.
+ Also some other minor cleanup and error handling fixes.
Also a bug fix when switching to editor, although this still messes up
when using the letters grammar.
Also updated readme with options, and some style improvements.
This makes it possible to download PGF files from servers where the PGF service
is installed.
I am also considering making commmand=download the default instead of
command=grammar.
It failed to delay table selection when the selector contains a run-time
variable, causing "gf: Prelude.(!!): index too large" instead.
Also:
+ Show better source locations on unexpected errors, to aid bug hunting.
+ Removed unused SourceGrammar argument to value2term.
The work done by the partial evaluator is now divied in two stages:
- A static "term traversal" stage that happens only once per term and uses
only statically known information. In particular, the values of lambda bound
variables are unknown during this stage. Some tables are transformed to
reduce the cost of pattern matching.
- A dynamic "function application" stage, where function bodies can be
evaluated repeatedly with different arguments, without the term traversal
overhead and without recomputing statically known information.
Also the treatment of predefined functions has been reworked to take advantage
of the staging and better handle partial applications.
