A lexer is an object governing the styling of the various elements of the source code. In other words it is the “syntax highlighting” that discover elements in the text and applies styles.
The Lexer classes simply encapsulates various style elements [1] for example:
Take the LexerPython, it has various attributes... it can recognize in the document the “commentline”, “commands”, “number”, and apply styles to them. In the attribute is defined the style.
>>> lp = LexerPython()
>>> lp.comment
< TextStyle ... >
To set a lexer:
>>> s = Scintilla()
>>> s.set_lexer("python")
>>> s.set_lexer(LexerPython()) # alternative
To customize a lexer with styles that you want you have to subclass it in this manner:
class customLexer(LexerPython):
def __init__(self):
super(customLexer,self).__init__()
self.comment = TextStyle(color = "blue", bold = True, italic = True)
self.number = TextStyle(color = "green")
and then you have to apply the lexer:
>>> s.set_lexer(customLexer())
Note
The current implementation has hardcoded lexer definition, in a future release will be introduced config files ( in .ini style or in xml).
To retrieve the possible elements to style you can import the lexer and print the dir() return value... Excluding the “id”,”style_ids”,”keywords” attributes.
For example:
>>> from gtkscintilla.lexer import LexerPython
>>> l = dir(LexerPython)
>>> filter(lambda x: not x[0]=='_',l) # I've filtered the attributes starting with "_"
['bracebad', 'bracelight', 'character', 'classname', 'commentblock',
'commentline', 'decorator', 'default', 'defname', 'id', 'identifier',
'keywords', 'number', 'operator', 'string', 'stringeol', 'style_ids',
'triple', 'tripledouble', 'word', 'word2']
Here the complete list of lexers with the associated language [2] :
| Name | Lexer class |
|---|---|
| abaqus | LexerAbaqus |
| ada | LexerAda |
| asm | LexerAsm |
| asn1 | LexerAsn1 |
| au3 | LexerAu3 |
| baan | LexerBaan |
| bash | LexerBash |
| batch | LexerBatch |
| bullant | LexerBullant |
| caml | LexerCaml |
| cmake | LexerCmake |
| conf | LexerConf |
| cpp | LexerCpp |
| csound | LexerCsound |
| css | LexerCss |
| d | LexerD |
| diff | LexerDiff |
| eiffel | LexerEiffel |
| eiffelkw | LexerEiffelkw |
| erlang | LexerErlang |
| errorlist | LexerErrorlist |
| escript | LexerEscript |
| f77 | LexerF77 |
| flagship | LexerFlagship |
| forth | LexerForth |
| fortran | LexerFortran |
| gap | LexerGap |
| inno | LexerInno |
| kix | LexerKix |
| latex | LexerLatex |
| lisp | LexerLisp |
| lot | LexerLot |
| lout | LexerLout |
| lua | LexerLua |
| makefile | LexerMakefile |
| matlab | LexerMatlab |
| metapost | LexerMetapost |
| mmixal | LexerMmixal |
| nimrod | LexerNimrod |
| nncrontab | LexerNncrontab |
| nsis | LexerNsis |
| octave | LexerOctave |
| opal | LexerOpal |
| pascal | LexerPascal |
| perl | LexerPerl |
| pov | LexerPov |
| powerpro | LexerPowerpro |
| powershell | LexerPowershell |
| ps | LexerPs |
| python | LexerPython |
| r | LexerR |
| rebol | LexerRebol |
| ruby | LexerRuby |
| smalltalk | LexerSmalltalk |
| specman | LexerSpecman |
| spice | LexerSpice |
| sql | LexerSql |
| tcl | LexerTcl |
| tex | LexerTex |
| vb | LexerVb |
| vbscript | LexerVbscript |
| verilog | LexerVerilog |
| vhdl | LexerVhdl |
| xml | LexerXml |
| yaml | LexerYaml |
| [1] | Lexer class is a mere data container, the styles are applied with the set_lexer() method |
| [2] | Note that this list is generated, I haven’t found a good way to retrieve the “human representation” of the language name, please use some fantasy. |