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Diffstat (limited to 'vendor/github.com/urfave/cli/generate-flag-types')
| -rwxr-xr-x | vendor/github.com/urfave/cli/generate-flag-types | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/vendor/github.com/urfave/cli/generate-flag-types b/vendor/github.com/urfave/cli/generate-flag-types new file mode 100755 index 00000000..7147381c --- /dev/null +++ b/vendor/github.com/urfave/cli/generate-flag-types @@ -0,0 +1,255 @@ +#!/usr/bin/env python +""" +The flag types that ship with the cli library have many things in common, and +so we can take advantage of the `go generate` command to create much of the +source code from a list of definitions. These definitions attempt to cover +the parts that vary between flag types, and should evolve as needed. + +An example of the minimum definition needed is: + + { + "name": "SomeType", + "type": "sometype", + "context_default": "nil" + } + +In this example, the code generated for the `cli` package will include a type +named `SomeTypeFlag` that is expected to wrap a value of type `sometype`. +Fetching values by name via `*cli.Context` will default to a value of `nil`. + +A more complete, albeit somewhat redundant, example showing all available +definition keys is: + + { + "name": "VeryMuchType", + "type": "*VeryMuchType", + "value": true, + "dest": false, + "doctail": " which really only wraps a []float64, oh well!", + "context_type": "[]float64", + "context_default": "nil", + "parser": "parseVeryMuchType(f.Value.String())", + "parser_cast": "[]float64(parsed)" + } + +The meaning of each field is as follows: + + name (string) - The type "name", which will be suffixed with + `Flag` when generating the type definition + for `cli` and the wrapper type for `altsrc` + type (string) - The type that the generated `Flag` type for `cli` + is expected to "contain" as its `.Value` member + value (bool) - Should the generated `cli` type have a `Value` + member? + dest (bool) - Should the generated `cli` type support a + destination pointer? + doctail (string) - Additional docs for the `cli` flag type comment + context_type (string) - The literal type used in the `*cli.Context` + reader func signature + context_default (string) - The literal value used as the default by the + `*cli.Context` reader funcs when no value is + present + parser (string) - Literal code used to parse the flag `f`, + expected to have a return signature of + (value, error) + parser_cast (string) - Literal code used to cast the `parsed` value + returned from the `parser` code +""" + +from __future__ import print_function, unicode_literals + +import argparse +import json +import os +import subprocess +import sys +import tempfile +import textwrap + + +class _FancyFormatter(argparse.ArgumentDefaultsHelpFormatter, + argparse.RawDescriptionHelpFormatter): + pass + + +def main(sysargs=sys.argv[:]): + parser = argparse.ArgumentParser( + description='Generate flag type code!', + formatter_class=_FancyFormatter) + parser.add_argument( + 'package', + type=str, default='cli', choices=_WRITEFUNCS.keys(), + help='Package for which flag types will be generated' + ) + parser.add_argument( + '-i', '--in-json', + type=argparse.FileType('r'), + default=sys.stdin, + help='Input JSON file which defines each type to be generated' + ) + parser.add_argument( + '-o', '--out-go', + type=argparse.FileType('w'), + default=sys.stdout, + help='Output file/stream to which generated source will be written' + ) + parser.epilog = __doc__ + + args = parser.parse_args(sysargs[1:]) + _generate_flag_types(_WRITEFUNCS[args.package], args.out_go, args.in_json) + return 0 + + +def _generate_flag_types(writefunc, output_go, input_json): + types = json.load(input_json) + + tmp = tempfile.NamedTemporaryFile(suffix='.go', delete=False) + writefunc(tmp, types) + tmp.close() + + new_content = subprocess.check_output( + ['goimports', tmp.name] + ).decode('utf-8') + + print(new_content, file=output_go, end='') + output_go.flush() + os.remove(tmp.name) + + +def _set_typedef_defaults(typedef): + typedef.setdefault('doctail', '') + typedef.setdefault('context_type', typedef['type']) + typedef.setdefault('dest', True) + typedef.setdefault('value', True) + typedef.setdefault('parser', 'f.Value, error(nil)') + typedef.setdefault('parser_cast', 'parsed') + + +def _write_cli_flag_types(outfile, types): + _fwrite(outfile, """\ + package cli + + // WARNING: This file is generated! + + """) + + for typedef in types: + _set_typedef_defaults(typedef) + + _fwrite(outfile, """\ + // {name}Flag is a flag with type {type}{doctail} + type {name}Flag struct {{ + Name string + Usage string + EnvVar string + Hidden bool + """.format(**typedef)) + + if typedef['value']: + _fwrite(outfile, """\ + Value {type} + """.format(**typedef)) + + if typedef['dest']: + _fwrite(outfile, """\ + Destination *{type} + """.format(**typedef)) + + _fwrite(outfile, "\n}\n\n") + + _fwrite(outfile, """\ + // String returns a readable representation of this value + // (for usage defaults) + func (f {name}Flag) String() string {{ + return FlagStringer(f) + }} + + // GetName returns the name of the flag + func (f {name}Flag) GetName() string {{ + return f.Name + }} + + // {name} looks up the value of a local {name}Flag, returns + // {context_default} if not found + func (c *Context) {name}(name string) {context_type} {{ + return lookup{name}(name, c.flagSet) + }} + + // Global{name} looks up the value of a global {name}Flag, returns + // {context_default} if not found + func (c *Context) Global{name}(name string) {context_type} {{ + if fs := lookupGlobalFlagSet(name, c); fs != nil {{ + return lookup{name}(name, fs) + }} + return {context_default} + }} + + func lookup{name}(name string, set *flag.FlagSet) {context_type} {{ + f := set.Lookup(name) + if f != nil {{ + parsed, err := {parser} + if err != nil {{ + return {context_default} + }} + return {parser_cast} + }} + return {context_default} + }} + """.format(**typedef)) + + +def _write_altsrc_flag_types(outfile, types): + _fwrite(outfile, """\ + package altsrc + + import ( + "gopkg.in/urfave/cli.v1" + ) + + // WARNING: This file is generated! + + """) + + for typedef in types: + _set_typedef_defaults(typedef) + + _fwrite(outfile, """\ + // {name}Flag is the flag type that wraps cli.{name}Flag to allow + // for other values to be specified + type {name}Flag struct {{ + cli.{name}Flag + set *flag.FlagSet + }} + + // New{name}Flag creates a new {name}Flag + func New{name}Flag(fl cli.{name}Flag) *{name}Flag {{ + return &{name}Flag{{{name}Flag: fl, set: nil}} + }} + + // Apply saves the flagSet for later usage calls, then calls the + // wrapped {name}Flag.Apply + func (f *{name}Flag) Apply(set *flag.FlagSet) {{ + f.set = set + f.{name}Flag.Apply(set) + }} + + // ApplyWithError saves the flagSet for later usage calls, then calls the + // wrapped {name}Flag.ApplyWithError + func (f *{name}Flag) ApplyWithError(set *flag.FlagSet) error {{ + f.set = set + return f.{name}Flag.ApplyWithError(set) + }} + """.format(**typedef)) + + +def _fwrite(outfile, text): + print(textwrap.dedent(text), end='', file=outfile) + + +_WRITEFUNCS = { + 'cli': _write_cli_flag_types, + 'altsrc': _write_altsrc_flag_types +} + +if __name__ == '__main__': + sys.exit(main()) |