Trac #32650: sage.misc.latex: Replace have_... functions by Features

... or more generally, replacing all uses of
`sage.misc.os_tools.have_program` by `Executable`

URL: https://trac.sagemath.org/32650
Reported by: mkoeppe
Ticket author(s): Sébastien Labbé
Reviewer(s): Matthias Koeppe

build/pkgs/pdf2svg/SPKG.rst

@@ -0,0 +1,19 @@
+pdf2svg - PDF to SVG convertor
+==============================
+
+Description
+-----------
+
+pdf2svg is a tiny command-line utility using Cairo and Poppler to convert PDF
+documents into SVG files. Multi-page PDF can be split up to one SVG per page by
+passing a file naming specification.
+
+License
+-------
+
+GPL
+
+Upstream Contact
+----------------
+
+http://cityinthesky.co.uk/opensource/pdf2svg/

build/pkgs/pdf2svg/distros/alpine.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/arch.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/conda.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/cygwin.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/debian.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/fedora.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/freebsd.txt

@@ -0,0 +1 @@
+graphics/pdf2svg

build/pkgs/pdf2svg/distros/homebrew.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/macports.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/nix.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/opensuse.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/repology.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/distros/void.txt

@@ -0,0 +1 @@
+pdf2svg

build/pkgs/pdf2svg/spkg-configure.m4

@@ -0,0 +1,5 @@
+SAGE_SPKG_CONFIGURE([pdf2svg], [
+   AC_PATH_PROG([PDF2SVG], [pdf2svg])
+   AS_IF([test -z "$ac_cv_path_PDF2SVG"], [sage_spkg_install_pdf2svg=yes])
+])
+

build/pkgs/pdf2svg/type

@@ -0,0 +1 @@
+optional

src/sage/doctest/external.py

@@ -49,7 +49,7 @@ def has_internet():
     EXAMPLES::
 
         sage: from sage.doctest.external import has_internet
-        sage: has_internet()                                 # random, optional -- internet
+        sage: has_internet()  # random, optional -- internet
         FeatureTestResult('internet', True)
     """
     from sage.features.internet import Internet
@@ -62,20 +62,50 @@ def has_latex():
     EXAMPLES::
 
         sage: from sage.doctest.external import has_latex
-        sage: has_latex() # random, optional - latex
-        True
+        sage: has_latex() # optional - latex
+        FeatureTestResult('latex', True)
     """
-    from sage.misc.latex import _run_latex_, _latex_file_
-    from sage.misc.temporary_file import tmp_filename
-    try:
-        f = tmp_filename(ext='.tex')
-        O = open(f, 'w')
-        O.write(_latex_file_('2+3'))
-        O.close()
-        _run_latex_(f)
-        return True
-    except Exception:
-        return False
+    from sage.features.latex import latex
+    return latex().is_present()
+
+def has_xelatex():
+    """
+    Test if xelatex is available.
+
+    EXAMPLES::
+
+        sage: from sage.doctest.external import has_xelatex
+        sage: has_xelatex()   # optional - xelatex
+        FeatureTestResult('xelatex', True)
+    """
+    from sage.features.latex import xelatex
+    return xelatex().is_present()
+
+def has_pdflatex():
+    """
+    Test if pdflatex is available.
+
+    EXAMPLES::
+
+        sage: from sage.doctest.external import has_pdflatex
+        sage: has_pdflatex()   # optional - pdflatex
+        FeatureTestResult('pdflatex', True)
+    """
+    from sage.features.latex import pdflatex
+    return pdflatex().is_present()
+
+def has_lualatex():
+    """
+    Test if lualatex is available.
+
+    EXAMPLES::
+
+        sage: from sage.doctest.external import has_lualatex
+        sage: has_lualatex()   # optional - lualatex
+        FeatureTestResult('lualatex', True)
+    """
+    from sage.features.latex import lualatex
+    return lualatex().is_present()
 
 def has_magma():
     """
@@ -274,6 +304,32 @@ def has_imagemagick():
     from sage.features.imagemagick import ImageMagick
     return ImageMagick().is_present()
 
+def has_dvipng():
+    """
+    Test if dvipng is available.
+
+    EXAMPLES::
+
+        sage: from sage.doctest.external import has_dvipng
+        sage: has_dvipng() # optional -- dvipng
+        FeatureTestResult('dvipng', True)
+    """
+    from sage.features.dvipng import dvipng
+    return dvipng().is_present()
+
+def has_pdf2svg():
+    """
+    Test if pdf2svg is available.
+
+    EXAMPLES::
+
+        sage: from sage.doctest.external import has_pdf2svg
+        sage: has_pdf2svg() # optional -- pdf2svg
+        FeatureTestResult('pdf2svg', True)
+    """
+    from sage.features.pdf2svg import pdf2svg
+    return pdf2svg().is_present()
+
 def has_rubiks():
     """
     Test if the rubiks package (``cu2``, ``cubex``, ``dikcube``,
@@ -345,21 +401,26 @@ class AvailableSoftware(object):
         sage: external_software
         ['4ti2',
          'cplex',
+         'dvipng',
          'ffmpeg',
          'graphviz',
          'gurobi',
          'imagemagick',
          'internet',
          'latex',
+         'lualatex',
          'macaulay2',
          'magma',
          'maple',
          'mathematica',
          'matlab',
          'octave',
          'pandoc',
+         'pdf2svg',
+         'pdflatex',
          'rubiks',
-         'scilab']
+         'scilab',
+         'xelatex']
         sage: 'internet' in available_software # random, optional - internet
         True
         sage: available_software.issuperset(set(['internet','latex'])) # random, optional - internet latex

src/sage/features/dvipng.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+r"""
+Check for dvipng
+"""
+# ****************************************************************************
+#       Copyright (C) 2021 Sebastien Labbe <slabqc@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
+
+from . import Executable
+
+class dvipng(Executable):
+    r"""
+    A :class:`sage.features.Feature` describing the presence of ``dvipng``
+
+    EXAMPLES::
+
+        sage: from sage.features.dvipng import dvipng
+        sage: dvipng().is_present()             # optional: dvipng
+        FeatureTestResult('dvipng', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.dvipng import dvipng
+            sage: isinstance(dvipng(), dvipng)
+            True
+        """
+        Executable.__init__(self, "dvipng", executable="dvipng",
+                            url="https://savannah.nongnu.org/projects/dvipng/")

src/sage/features/latex.py

@@ -0,0 +1,138 @@
+# -*- coding: utf-8 -*-
+r"""
+Check for pdflatex and equivalent programs
+"""
+# ****************************************************************************
+#       Copyright (C) 2021 Sebastien Labbe <slabqc@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
+
+from . import Executable, FeatureTestResult
+
+class latex(Executable):
+    r"""
+    A :class:`sage.features.Feature` describing the presence of ``latex``
+
+    EXAMPLES::
+
+        sage: from sage.features.latex import latex
+        sage: latex().is_present()             # optional: latex
+        FeatureTestResult('latex', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.latex import latex
+            sage: isinstance(latex(), latex)
+            True
+        """
+        Executable.__init__(self, "latex", executable="latex",
+                            url="https://www.latex-project.org/")
+
+    def is_functional(self):
+        r"""
+        Return whether `latex` in the path is functional.
+
+        EXAMPLES:
+
+            sage: from sage.features.latex import latex
+            sage: latex().is_functional()             # optional: latex
+            FeatureTestResult('latex', True)
+        """
+        lines = []
+        lines.append(r"\documentclass{article}")
+        lines.append(r"\begin{document}")
+        lines.append(r"$\alpha+2$")
+        lines.append(r"\end{document}")
+        content = '\n'.join(lines)
+
+        # create a simple tex file with the content
+        from sage.misc.temporary_file import tmp_filename
+        base_filename_tex = tmp_filename(ext='.tex')
+        with open(base_filename_tex, 'w') as f:
+            f.write(content)
+        import os
+        base, filename_tex = os.path.split(base_filename_tex)
+
+        # running latex
+        from subprocess import run
+        cmd = ['latex', '-interaction=nonstopmode', filename_tex]
+        cmd = ' '.join(cmd)
+        result = run(cmd, shell=True, cwd=base, capture_output=True, text=True)
+
+        # return
+        if result.returncode == 0:
+            return FeatureTestResult(self, True)
+        else:
+            return FeatureTestResult(self, False, reason="Running latex on "
+                        "a sample file returned non-zero "
+                        "exit status {}".format(result.returncode))
+
+class pdflatex(Executable):
+    r"""
+    A :class:`sage.features.Feature` describing the presence of ``pdflatex``
+
+    EXAMPLES::
+
+        sage: from sage.features.latex import pdflatex
+        sage: pdflatex().is_present()             # optional: pdflatex
+        FeatureTestResult('pdflatex', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.latex import pdflatex
+            sage: isinstance(pdflatex(), pdflatex)
+            True
+        """
+        Executable.__init__(self, "pdflatex", executable="pdflatex",
+                            url="https://www.latex-project.org/")
+
+class xelatex(Executable):
+    r"""
+    A :class:`sage.features.Feature` describing the presence of ``xelatex``
+
+    EXAMPLES::
+
+        sage: from sage.features.latex import xelatex
+        sage: xelatex().is_present()             # optional: xelatex
+        FeatureTestResult('xelatex', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.latex import xelatex
+            sage: isinstance(xelatex(), xelatex)
+            True
+        """
+        Executable.__init__(self, "xelatex", executable="xelatex",
+                            url="https://www.latex-project.org/")
+
+class lualatex(Executable):
+    r"""
+    A :class:`sage.features.Feature` describing the presence of ``lualatex``
+
+    EXAMPLES::
+
+        sage: from sage.features.latex import lualatex
+        sage: lualatex().is_present()             # optional: lualatex
+        FeatureTestResult('lualatex', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.latex import lualatex
+            sage: isinstance(lualatex(), lualatex)
+            True
+        """
+        Executable.__init__(self, "lualatex", executable="lualatex",
+                            url="https://www.latex-project.org/")