Haskell diagrams-builder 解析错误

Question

我正在尝试将 diagrams-builder 包与 LaTeX 一起使用，以便在线生成图表。按照教程 here，我有一个名为 test.tex 的文件，其中包含以下内容：

\documentclass[10pt]{article}

\usepackage[backend=ps, extension=eps, outputdir=diagrams]{diagrams-latex}
\usepackage{graphicx}

\begin{document}
\begin{diagram}[width=300,height=200]
{-# LANGUAGE FlexibleContexts #-}
dia = circle 1 
\end{diagram}

\end{document}

我创建了一个名为 diagrams 的空目录并尝试编译，结果却被告知 diagrams-builder-ps.[=22 自动生成的文件看起来存在解析错误=]

$ pdflatex --enable-write18 --shell-escape test.tex
This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016) (preloaded format=pdflatex)
 \write18 enabled.
entering extended mode
(./test.tex
LaTeX2e <2016/03/31>
Babel <3.9r> and hyphenation patterns for 83 language(s) loaded.
(/usr/local/texlive/2016/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/local/texlive/2016/texmf-dist/tex/latex/base/size10.clo))
(/Users/nhalford/Library/texmf/tex/diagrams-latex.sty
(/usr/local/texlive/2016/texmf-dist/tex/latex/moreverb/moreverb.sty
(/usr/local/texlive/2016/texmf-dist/tex/latex/tools/verbatim.sty))
(/usr/local/texlive/2016/texmf-dist/tex/latex/xkeyval/xkeyval.sty
(/usr/local/texlive/2016/texmf-dist/tex/generic/xkeyval/xkeyval.tex
(/usr/local/texlive/2016/texmf-dist/tex/generic/xkeyval/xkvutils.tex
(/usr/local/texlive/2016/texmf-dist/tex/generic/xkeyval/keyval.tex))))
(/usr/local/texlive/2016/texmf-dist/tex/latex/base/ifthen.sty))
(/usr/local/texlive/2016/texmf-dist/tex/latex/graphics/graphicx.sty
(/usr/local/texlive/2016/texmf-dist/tex/latex/graphics/graphics.sty
(/usr/local/texlive/2016/texmf-dist/tex/latex/graphics/trig.sty)
(/usr/local/texlive/2016/texmf-dist/tex/latex/graphics-cfg/graphics.cfg)
(/usr/local/texlive/2016/texmf-dist/tex/latex/pdftex-def/pdftex.def
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/infwarerr.sty)
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/ltxcmds.sty))))
No file test.aux.
(/usr/local/texlive/2016/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
[Loading MPS to PDF converter (version 2006.09.02).]
) (/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/pdftexcmds.sty
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/ifluatex.sty)
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/ifpdf.sty))
(/usr/local/texlive/2016/texmf-dist/tex/latex/oberdiek/epstopdf-base.sty
(/usr/local/texlive/2016/texmf-dist/tex/latex/oberdiek/grfext.sty
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/kvdefinekeys.sty))
(/usr/local/texlive/2016/texmf-dist/tex/latex/oberdiek/kvoptions.sty
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/kvsetkeys.sty
(/usr/local/texlive/2016/texmf-dist/tex/generic/oberdiek/etexcmds.sty)))
(/usr/local/texlive/2016/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg))
Opening diagrams-latex stream diagrams/test-diagrams-latex-fig1.hs Error while compiling diagrams/test-diagrams-latex-fig1.hs
/var/folders/2g/_6mplpfn4fl338wr3cj949440000gn/T/Diagram58258-0.hs:3:20: error:
    parse error on input ‘-’



Package diagrams-latex Warning: Conversion of diagrams/test-diagrams-latex-fig1
.hs failed.


Package diagrams-latex Warning: Please convert diagrams/test-diagrams-latex-fig
1.hs manually.

(./test.aux) )
No pages of output.
Transcript written on test.log.

我在尝试直接在 .hs 文件上运行 diagrams-builder-ps 或 diagrams-builder-cairo 时也遇到此错误：

$ cd diagrams
$ ls
test-diagrams-latex-fig1.hs
$ diagrams-builder-ps -w 300 -h 200 test-diagrams-latex-fig1.hs
Error while compiling test-diagrams-latex-fig1.hs
/var/folders/2g/_6mplpfn4fl338wr3cj949440000gn/T/Diagram58289-0.hs:3:20: error:
    parse error on input ‘-’

$ diagrams-builder-cairo -w 300 -h 200 test-diagrams-latex-fig1.hs
Error while compiling test-diagrams-latex-fig1.hs
/var/folders/2g/_6mplpfn4fl338wr3cj949440000gn/T/Diagram58294-0.hs:3:20: error:
    parse error on input ‘-’

$ cat test-diagrams-latex-fig1.hs
{-# LANGUAGE FlexibleContexts #-}
dia = circle 1
$

不幸的是，系统立即删除了带有解析错误的临时 .hs 文件，因此我无法检查该文件以查看究竟是什么导致了此问题。

感谢您的帮助！

Answer 1

哦，我想我只是想出了一定是错的，虽然我不确定修复它的最佳方法。关键是这一行：

/var/folders/2g/_6mplpfn4fl338wr3cj949440000gn/T/Diagram58289-0.hs:3:20: error:

注意临时文件的名称是Diagram58289-0.hs。 diagrams-builder 调用 openTempFile (see here) 然后使用结果文件的基本名称作为模块的名称。所以 Diagram58289-0.hs 的内容必须是这样的：

{-# LANGUAGE FlexibleContexts #-}

module Diagram58289-0 where

dia = circle 1

问题是连字符在模块名称中无效，因此出现解析错误（果然，它在第 3 行的第 20 列中）。

虽然documentation for openTempFile says the created file will have a name of the form "fooXXX.ext where XXX is some random number", obviously that is not what is happening here. And indeed, it looks like the behavior of openTempFile changed recently；现在它将始终包含一个连字符。我猜这种行为在 base-4.10 中发生了变化，因此它会显示给使用 GHC 8.2 的任何人。

我有 created an issue on the diagrams-builder issue tracker 来跟踪这个问题。目前，一种解决方案是降级到 GHC 8.0，但这可能不是一个非常有吸引力的选择。

Haskell diagrams-builder 解析错误

Parse error with Haskell diagrams-builder

haskell

latex

haskell-diagrams