Package SCons :: Module Environment :: Class SubstitutionEnvironment

Class SubstitutionEnvironment

Known Subclasses:

Base

Base class for different flavors of construction environments.

This class contains a minimal set of methods that handle contruction variable expansion and conversion of strings to Nodes, which may or may not be actually useful as a stand-alone class. Which methods ended up in this class is pretty arbitrary right now. They're basically the ones which we've empirically determined are common to the different construction environment subclasses, and most of the others that use or touch the underlying dictionary of construction variables.

Eventually, this class should contain all the methods that we determine are necessary for a "minimal" interface to the build engine. A full "native Python" SCons environment has gotten pretty heavyweight with all of the methods and Tools and construction variables we've jammed in there, so it would be nice to have a lighter weight alternative for interfaces that don't need all of the bells and whistles. (At some point, we'll also probably rename this class "Base," since that more reflects what we want this class to become, but because we've released comments that tell people to subclass Environment.Base to create their own flavors of construction environment, we'll save that for a future refactoring when this class actually becomes useful.)

Instance Methods

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__init__(self, **kw)
Initialization of an underlying SubstitutionEnvironment class.

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_init_special(self)
Initial the dispatch tables for special handling of special construction variables.

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__cmp__(self, other)

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__delitem__(self, key)

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__getitem__(self, key)

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__setitem__(self, key, value)

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get(self, key, default=None)
Emulates the get() method of dictionaries.

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has_key(self, key)

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__contains__(self, key)

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items(self)

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arg2nodes(self, args, node_factory=<class SCons.Environment._Null at 0x25f0770>, lookup_list=<class SCons.Environment._Null at 0x25f0770>, **kw)

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gvars(self)

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lvars(self)

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subst(self, string, raw=0, target=None, source=None, conv=None, executor=None)
Recursively interpolates construction variables from the Environment into the specified string, returning the expanded result.

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subst_kw(self, kw, raw=0, target=None, source=None)

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subst_list(self, string, raw=0, target=None, source=None, conv=None, executor=None)
Calls through to SCons.Subst.scons_subst_list().

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subst_path(self, path, target=None, source=None)
Substitute a path list, turning EntryProxies into Nodes and leaving Nodes (and other objects) as-is.

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subst_target_source(self, string, raw=0, target=None, source=None, conv=None, executor=None)
Recursively interpolates construction variables from the Environment into the specified string, returning the expanded result.

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backtick(self, command)

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AddMethod(self, function, name=None)
Adds the specified function as a method of this construction environment with the specified name.

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RemoveMethod(self, function)
Removes the specified function's MethodWrapper from the added_methods list, so we don't re-bind it when making a clone.

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Override(self, overrides)
Produce a modified environment whose variables are overriden by the overrides dictionaries.

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ParseFlags(self, *flags)
Parse the set of flags and return a dict with the flags placed in the appropriate entry.

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MergeFlags(self, args, unique=1, dict=None)
Merge the dict in args into the construction variables of this env, or the passed-in dict.

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Class Variables

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__metaclass__ = SCons.Memoize.Memoized_Metaclass

Method Details

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subst(self, string, raw=0, target=None, source=None, conv=None, executor=None)

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Recursively interpolates construction variables from the Environment into the specified string, returning the expanded result. Construction variables are specified by a $ prefix in the string and begin with an initial underscore or alphabetic character followed by any number of underscores or alphanumeric characters. The construction variable names may be surrounded by curly braces to separate the name from trailing characters.

subst_list(self, string, raw=0, target=None, source=None, conv=None, executor=None)

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Calls through to SCons.Subst.scons_subst_list(). See the documentation for that function.

subst_target_source(self, string, raw=0, target=None, source=None, conv=None, executor=None)

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AddMethod(self, function, name=None)

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Adds the specified function as a method of this construction environment with the specified name. If the name is omitted, the default name is the name of the function itself.

Override(self, overrides)

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Produce a modified environment whose variables are overriden by the overrides dictionaries. "overrides" is a dictionary that will override the variables of this environment.

This function is much more efficient than Clone() or creating a new Environment because it doesn't copy the construction environment dictionary, it just wraps the underlying construction environment, and doesn't even create a wrapper object if there are no overrides.

ParseFlags(self, *flags)

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Parse the set of flags and return a dict with the flags placed in the appropriate entry. The flags are treated as a typical set of command-line flags for a GNU-like toolchain and used to populate the entries in the dict immediately below. If one of the flag strings begins with a bang (exclamation mark), it is assumed to be a command and the rest of the string is executed; the result of that evaluation is then added to the dict.

MergeFlags(self, args, unique=1, dict=None)

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Merge the dict in args into the construction variables of this env, or the passed-in dict. If args is not a dict, it is converted into a dict using ParseFlags. If unique is not set, the flags are appended rather than merged.