Improve visual representation of SQL statements

This commit changes the lexer for tokenizing the user input from the
generic SqlLexer to the more specific PostgresLexer.

Additionally the color scheme has been changed from a custom on to
"terminal style", meaning that it will pick up the colors of the
terminal emulator (http://pygments.org/docs/styles/#ansiterminalstyle).

crate/crash/repl.py

@@ -23,15 +23,15 @@
 import os
 import re
 
-from pygments.lexers.sql import SqlLexer
+from pygments.lexers.sql import PostgresLexer
 from pygments.style import Style
 from prompt_toolkit.output.defaults import get_default_output
 from prompt_toolkit.styles.pygments import style_from_pygments_cls
 from pygments.token import (Keyword,
                             Comment,
                             Operator,
+                            Name,
                             Number,
-                            Literal,
                             String,
                             Error,
                             Token)
@@ -74,16 +74,17 @@ def _get_editing_mode():
 
 
 class CrateStyle(Style):
-    default_style = "noinherit"
+    default_style = ""
     styles = {
-        Keyword: 'bold #4b95a3',
-        Comment: '#757265',
-        Operator: '#e83131',
-        Number: '#be61ff',
-        Literal: '#ae81ff',
-        String: '#f4a33d',
-        Error: '#ff3300',
-        Token.Toolbar.Status.Key: '#4b95a3',
+        Keyword: 'bold ansibrightblue',
+        Comment: 'ansigray',
+        Operator: 'ansibrightred',
+        Name.Builtin: 'ansiblue',
+        Number: 'ansimagenta',
+        String: 'ansiyellow',
+        String.Single: 'ansibrightgreen',
+        Error: 'bold ansired',
+        Token.Toolbar.Status.Key: 'ansiblue',
     }
 
 
@@ -316,7 +317,7 @@ def loop(cmd, history_file):
     layout = create_layout(
         buffer=buf,
         multiline=True,
-        lexer=SqlLexer,
+        lexer=PostgresLexer,
         extra_input_processors=[
             ConditionalProcessor(
                 processor=HighlightMatchingBracketProcessor(chars='[](){}'),

setup.py

@@ -27,7 +27,7 @@
 
 requirements = [
     'colorama',
-    'Pygments>=2.0',
+    'Pygments>=2.4',
     'crate>=0.22.0',
     'appdirs>=1.2,<2.0',
     'prompt-toolkit>=2.0,<3.0'