thirdparty/google_appengine/lib/yaml/examples/yaml-highlight/yaml_hl.py
author Daniel Hans <Daniel.M.Hans@gmail.com>
Fri, 07 Aug 2009 01:27:24 +0200
changeset 2736 8f3935f0f4ba
parent 109 620f9b141567
permissions -rwxr-xr-x
Argument store added to updateEntityProperties. This argument determines if an entity should be stored in the data model after its properties are updated. It may be useful, for example, along with tasks (Task Queue API). One may want to make some modifications to an entity during execution of a task, but the developer is sure that at least one new task, which also wants to modify the entity, will be queued, so he or she can just update the entity without saving the changes to the data model, set the entity in memcache and the following task (which is to be executed very shortly) is to retrive the current entity from the memcache (without any expensive calls to the actual data model).

#!/usr/bin/python

import yaml, codecs, sys, os.path, optparse

class Style:

    def __init__(self, header=None, footer=None,
            tokens=None, events=None, replaces=None):
        self.header = header
        self.footer = footer
        self.replaces = replaces
        self.substitutions = {}
        for domain, Class in [(tokens, 'Token'), (events, 'Event')]:
            if not domain:
                continue
            for key in domain:
                name = ''.join([part.capitalize() for part in key.split('-')])
                cls = getattr(yaml, '%s%s' % (name, Class))
                value = domain[key]
                if not value:
                    continue
                start = value.get('start')
                end = value.get('end')
                if start:
                    self.substitutions[cls, -1] = start
                if end:
                    self.substitutions[cls, +1] = end

    def __setstate__(self, state):
        self.__init__(**state)

yaml.add_path_resolver(u'tag:yaml.org,2002:python/object:__main__.Style',
        [None], dict)
yaml.add_path_resolver(u'tag:yaml.org,2002:pairs',
        [None, u'replaces'], list)

class YAMLHighlight:

    def __init__(self, options):
        config = yaml.load(file(options.config, 'rb').read())
        self.style = config[options.style]
        if options.input:
            self.input = file(options.input, 'rb')
        else:
            self.input = sys.stdin
        if options.output:
            self.output = file(options.output, 'wb')
        else:
            self.output = sys.stdout

    def highlight(self):
        input = self.input.read()
        if input.startswith(codecs.BOM_UTF16_LE):
            input = unicode(input, 'utf-16-le')
        elif input.startswith(codecs.BOM_UTF16_BE):
            input = unicode(input, 'utf-16-be')
        else:
            input = unicode(input, 'utf-8')
        substitutions = self.style.substitutions
        tokens = yaml.scan(input)
        events = yaml.parse(input)
        markers = []
        number = 0
        for token in tokens:
            number += 1
            if token.start_mark.index != token.end_mark.index:
                cls = token.__class__
                if (cls, -1) in substitutions:
                    markers.append([token.start_mark.index, +2, number, substitutions[cls, -1]])
                if (cls, +1) in substitutions:
                    markers.append([token.end_mark.index, -2, number, substitutions[cls, +1]])
        number = 0
        for event in events:
            number += 1
            cls = event.__class__
            if (cls, -1) in substitutions:
                markers.append([event.start_mark.index, +1, number, substitutions[cls, -1]])
            if (cls, +1) in substitutions:
                markers.append([event.end_mark.index, -1, number, substitutions[cls, +1]])
        markers.sort()
        markers.reverse()
        chunks = []
        position = len(input)
        for index, weight1, weight2, substitution in markers:
            if index < position:
                chunk = input[index:position]
                for substring, replacement in self.style.replaces:
                    chunk = chunk.replace(substring, replacement)
                chunks.append(chunk)
                position = index
            chunks.append(substitution)
        chunks.reverse()
        result = u''.join(chunks)
        if self.style.header:
            self.output.write(self.style.header)
        self.output.write(result.encode('utf-8'))
        if self.style.footer:
            self.output.write(self.style.footer)

if __name__ == '__main__':
    parser = optparse.OptionParser()
    parser.add_option('-s', '--style', dest='style', default='ascii',
            help="specify the highlighting style", metavar='STYLE')
    parser.add_option('-c', '--config', dest='config',
            default=os.path.join(os.path.dirname(sys.argv[0]), 'yaml_hl.cfg'),
            help="set an alternative configuration file", metavar='CONFIG')
    parser.add_option('-i', '--input', dest='input', default=None,
            help="set the input file (default: stdin)", metavar='FILE')
    parser.add_option('-o', '--output', dest='output', default=None,
            help="set the output file (default: stdout)", metavar='FILE')
    (options, args) = parser.parse_args()
    hl = YAMLHighlight(options)
    hl.highlight()