Add fastcore.style: fast styling for friendly CLIs

.gitignore

@@ -142,3 +142,4 @@ checklink/cookies.txt
 # .gitconfig is now autogenerated
 .gitconfig
 
+_docs

fastcore/_modidx.py

@@ -31,7 +31,7 @@
                 'title': 'fastcore',
                 'tst_flags': '',
                 'user': 'fastai',
-                'version': '1.5.16'},
+                'version': '1.5.17'},
   'syms': { 'fastcore.all': {},
             'fastcore.basics': { 'fastcore.basics.AttrDict': 'https://fastcore.fast.ai/basics.html#attrdict',
                                  'fastcore.basics.AttrDict.copy': 'https://fastcore.fast.ai/basics.html#attrdict.copy',
@@ -361,6 +361,11 @@
                                  'fastcore.shutil.disk_usage': 'https://fastcore.fast.ai/shutil.html#disk_usage',
                                  'fastcore.shutil.move': 'https://fastcore.fast.ai/shutil.html#move',
                                  'fastcore.shutil.rmtree': 'https://fastcore.fast.ai/shutil.html#rmtree'},
+            'fastcore.style': { 'fastcore.style.S': 'https://fastcore.fast.ai/style.html#s',
+                                'fastcore.style.Style': 'https://fastcore.fast.ai/style.html#style',
+                                'fastcore.style.StyleCode': 'https://fastcore.fast.ai/style.html#stylecode',
+                                'fastcore.style.demo': 'https://fastcore.fast.ai/style.html#demo',
+                                'fastcore.style.style_codes': 'https://fastcore.fast.ai/style.html#style_codes'},
             'fastcore.test': { 'fastcore.test.ExceptionExpected': 'https://fastcore.fast.ai/test.html#exceptionexpected',
                                'fastcore.test.TEST_IMAGE': 'https://fastcore.fast.ai/test.html#test_image',
                                'fastcore.test.TEST_IMAGE_BW': 'https://fastcore.fast.ai/test.html#test_image_bw',

fastcore/style.py

@@ -0,0 +1,69 @@
+# AUTOGENERATED! DO NOT EDIT! File to edit: ../nbs/10_style.ipynb.
+
+# %% auto 0
+__all__ = ['style_codes', 'S', 'StyleCode', 'Style', 'demo']
+
+# %% ../nbs/10_style.ipynb 3
+# Source: https://misc.flogisoft.com/bash/tip_colors_and_formatting
+_base = 'red green yellow blue magenta cyan'
+_regular = f'black {_base} light_gray'
+_intense = 'dark_gray ' + ' '.join('light_'+o for o in _base.split()) + ' white'
+_fmt = dict(bold=1,dim=2,underline=4,reverse=7,hidden=8)
+
+# %% ../nbs/10_style.ipynb 4
+class StyleCode:
+    "An escape sequence for styling terminal text."
+    def __init__(self, name, code, typ): self.name,self.code,self.typ = name,code,typ
+    def __str__(self): return f'\033[{self.code}m'
+
+# %% ../nbs/10_style.ipynb 7
+def _mk_codes(s, start, typ, fmt=None, **kwargs):
+    d = {k:i for i,k in enumerate(s.split())} if isinstance(s, str) else s
+    res = {k if fmt is None else fmt.format(k):start+v for k,v in d.items()}
+    res.update(kwargs)
+    return {k:StyleCode(k,v,typ) for k,v in res.items()}
+
+# %% ../nbs/10_style.ipynb 8
+# Hardcode `reset_bold=22` since 21 is not always supported
+# See: https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
+style_codes = {**_mk_codes(_regular, 30,  'fg',                default=39),
+               **_mk_codes(_intense, 90,  'fg'),
+               **_mk_codes(_regular, 40,  'bg',    '{}_bg',    default_bg=49),
+               **_mk_codes(_intense, 100, 'bg',    '{}_bg'),
+               **_mk_codes(_fmt,     0,   'fmt'),
+               **_mk_codes(_fmt,     21,  'reset', 'reset_{}', reset=0, reset_bold=22)}
+
+# %% ../nbs/10_style.ipynb 9
+def _reset_code(s):
+    if s.typ == 'fg':  return style_codes['default']
+    if s.typ == 'bg':  return style_codes['default_bg']
+    if s.typ == 'fmt': return style_codes['reset_'+s.name]
+
+# %% ../nbs/10_style.ipynb 10
+class Style:
+    "A minimal terminal text styler."
+    def __init__(self, codes=None): self.codes = [] if codes is None else codes
+    def __dir__(self): return style_codes.keys()
+    def __getattr__(self, k): return Style(self.codes+[style_codes[k]])
+    def __call__(self, obj):
+        set_ = ''.join(str(o) for o in self.codes)
+        reset = ''.join('' if o is None else str(o) for o in set(_reset_code(o) for o in self.codes))
+        return set_ + str(obj) + reset
+    def __repr__(self):
+        nm = type(self).__name__
+        res = f'<{nm}: '
+        res += ' '.join(o.name for o in self.codes) if self.codes else 'none'
+        return res+'>'
+
+# %% ../nbs/10_style.ipynb 12
+S = Style()
+
+# %% ../nbs/10_style.ipynb 25
+def _demo(name, code):
+    s = getattr(S,name)
+    print(s(f'{code.code:>3}    {name:16}'))
+
+# %% ../nbs/10_style.ipynb 26
+def demo():
+    "Demonstrate all available styles and their codes."
+    for k,v in style_codes.items(): _demo(k,v)