@Override
void validate(final ValidationEnvironment env) throws EvalException {
ValidationEnvironment localEnv = new ValidationEnvironment(env);
FunctionSignature sig = signature.getSignature();
FunctionSignature.Shape shape = sig.getShape();
ImmutableList<String> names = sig.getNames();
List<Expression> defaultExpressions = signature.getDefaultValues();
int positionals = shape.getPositionals();
int mandatoryPositionals = shape.getMandatoryPositionals();
int namedOnly = shape.getNamedOnly();
int mandatoryNamedOnly = shape.getMandatoryNamedOnly();
boolean starArg = shape.hasStarArg();
boolean kwArg = shape.hasKwArg();
int named = positionals + namedOnly;
int args = named + (starArg ? 1 : 0) + (kwArg ? 1 : 0);
int startOptionals = mandatoryPositionals;
int endOptionals = named - mandatoryNamedOnly;
int j = 0; // index for the defaultExpressions
for (int i = 0; i < args; i++) {
String name = names.get(i);
if (startOptionals <= i && i < endOptionals) {
defaultExpressions.get(j++).validate(env);
}
localEnv.declare(name, getLocation());
}
for (Statement stmts : statements) {
stmts.validate(localEnv);
}
}
/** Create a function using a signature with defaults */
public MixedModeFunction(
String name, FunctionSignature.WithValues<Object, SkylarkType> signature, Location location) {
super(name);
// TODO(bazel-team): lift the following limitations, by actually implementing
// the full function call protocol.
FunctionSignature sig = signature.getSignature();
FunctionSignature.Shape shape = sig.getShape();
Preconditions.checkArgument(
!shape.hasKwArg() && !shape.hasStarArg() && shape.getNamedOnly() == 0,
"no star, star-star or named-only parameters (for now)");
this.signature = signature;
this.parameters = ImmutableList.copyOf(sig.getNames());
this.numMandatoryParameters = shape.getMandatoryPositionals();
this.onlyNamedArguments = false;
this.location = location;
}
/**
* Process the caller-provided arguments into an array suitable for the callee (this function).
*/
public Object[] processArguments(
List<Object> args, @Nullable Map<String, Object> kwargs, @Nullable Location loc)
throws EvalException {
Object[] arguments = new Object[getArgArraySize()];
// extract function signature
FunctionSignature sig = signature.getSignature();
FunctionSignature.Shape shape = sig.getShape();
ImmutableList<String> names = sig.getNames();
List<Object> defaultValues = signature.getDefaultValues();
// Note that this variable will be adjusted down if there are extra positionals,
// after these extra positionals are dumped into starParam.
int numPositionalArgs = args.size();
int numMandatoryPositionalParams = shape.getMandatoryPositionals();
int numOptionalPositionalParams = shape.getOptionalPositionals();
int numMandatoryNamedOnlyParams = shape.getMandatoryNamedOnly();
int numOptionalNamedOnlyParams = shape.getOptionalNamedOnly();
boolean hasStarParam = shape.hasStarArg();
boolean hasKwParam = shape.hasKwArg();
int numPositionalParams = numMandatoryPositionalParams + numOptionalPositionalParams;
int numNamedOnlyParams = numMandatoryNamedOnlyParams + numOptionalNamedOnlyParams;
int numNamedParams = numPositionalParams + numNamedOnlyParams;
int kwParamIndex = names.size() - 1; // only valid if hasKwParam
// (1) handle positional arguments
if (hasStarParam) {
// Nota Bene: we collect extra positional arguments in a (tuple,) rather than a [list],
// and this is actually the same as in Python.
int starParamIndex = numNamedParams;
if (numPositionalArgs > numPositionalParams) {
arguments[starParamIndex] =
Tuple.copyOf(args.subList(numPositionalParams, numPositionalArgs));
numPositionalArgs = numPositionalParams; // clip numPositionalArgs
} else {
arguments[starParamIndex] = Tuple.EMPTY;
}
} else if (numPositionalArgs > numPositionalParams) {
throw new EvalException(
loc,
numPositionalParams > 0
? "too many (" + numPositionalArgs + ") positional arguments in call to " + this
: this + " does not accept positional arguments, but got " + numPositionalArgs);
}
for (int i = 0; i < numPositionalArgs; i++) {
arguments[i] = args.get(i);
}
// (2) handle keyword arguments
if (kwargs == null || kwargs.isEmpty()) {
// Easy case (2a): there are no keyword arguments.
// All arguments were positional, so check we had enough to fill all mandatory positionals.
if (numPositionalArgs < numMandatoryPositionalParams) {
throw new EvalException(
loc,
String.format(
"insufficient arguments received by %s (got %s, expected at least %s)",
this, numPositionalArgs, numMandatoryPositionalParams));
}
// We had no named argument, so fail if there were mandatory named-only parameters
if (numMandatoryNamedOnlyParams > 0) {
throw new EvalException(
loc, String.format("missing mandatory keyword arguments in call to %s", this));
}
// Fill in defaults for missing optional parameters, that were conveniently grouped together,
// thanks to the absence of mandatory named-only parameters as checked above.
if (defaultValues != null) {
int j = numPositionalArgs - numMandatoryPositionalParams;
int endOptionalParams = numPositionalParams + numOptionalNamedOnlyParams;
for (int i = numPositionalArgs; i < endOptionalParams; i++) {
arguments[i] = defaultValues.get(j++);
}
}
// If there's a kwParam, it's empty.
if (hasKwParam) {
// TODO(bazel-team): create a fresh mutable dict, like Python does
arguments[kwParamIndex] = ImmutableMap.<String, Object>of();
}
} else if (hasKwParam && numNamedParams == 0) {
// Easy case (2b): there are no named parameters, but there is a **kwParam.
// Therefore all keyword arguments go directly to the kwParam.
// Note that *starParam and **kwParam themselves don't count as named.
// Also note that no named parameters means no mandatory parameters that weren't passed,
// and no missing optional parameters for which to use a default. Thus, no loops.
// TODO(bazel-team): create a fresh mutable dict, like Python does
arguments[kwParamIndex] = kwargs; // NB: not 2a means kwarg isn't null
} else {
// Hard general case (2c): some keyword arguments may correspond to named parameters
HashMap<String, Object> kwArg = hasKwParam ? new HashMap<String, Object>() : null;
// For nicer stabler error messages, start by checking against
// an argument being provided both as positional argument and as keyword argument.
ArrayList<String> bothPosKey = new ArrayList<>();
for (int i = 0; i < numPositionalArgs; i++) {
String name = names.get(i);
if (kwargs.containsKey(name)) {
bothPosKey.add(name);
}
}
if (!bothPosKey.isEmpty()) {
throw new EvalException(
loc,
String.format(
"argument%s '%s' passed both by position and by name in call to %s",
(bothPosKey.size() > 1 ? "s" : ""), Joiner.on("', '").join(bothPosKey), this));
}
// Accept the arguments that were passed.
for (Map.Entry<String, Object> entry : kwargs.entrySet()) {
String keyword = entry.getKey();
Object value = entry.getValue();
int pos = names.indexOf(keyword); // the list should be short, so linear scan is OK.
if (0 <= pos && pos < numNamedParams) {
arguments[pos] = value;
} else {
if (!hasKwParam) {
List<String> unexpected =
Ordering.natural()
.sortedCopy(
Sets.difference(
kwargs.keySet(),
ImmutableSet.copyOf(names.subList(0, numNamedParams))));
throw new EvalException(
loc,
String.format(
"unexpected keyword%s '%s' in call to %s",
unexpected.size() > 1 ? "s" : "", Joiner.on("', '").join(unexpected), this));
}
if (kwArg.containsKey(keyword)) {
throw new EvalException(
loc,
String.format("%s got multiple values for keyword argument '%s'", this, keyword));
}
kwArg.put(keyword, value);
}
}
if (hasKwParam) {
// TODO(bazel-team): create a fresh mutable dict, like Python does
arguments[kwParamIndex] = ImmutableMap.copyOf(kwArg);
}
// Check that all mandatory parameters were filled in general case 2c.
// Note: it's possible that numPositionalArgs > numMandatoryPositionalParams but that's OK.
for (int i = numPositionalArgs; i < numMandatoryPositionalParams; i++) {
if (arguments[i] == null) {
throw new EvalException(
loc,
String.format(
"missing mandatory positional argument '%s' while calling %s",
names.get(i), this));
}
}
int endMandatoryNamedOnlyParams = numPositionalParams + numMandatoryNamedOnlyParams;
for (int i = numPositionalParams; i < endMandatoryNamedOnlyParams; i++) {
if (arguments[i] == null) {
throw new EvalException(
loc,
String.format(
"missing mandatory named-only argument '%s' while calling %s",
names.get(i), this));
}
}
// Get defaults for those parameters that weren't passed.
if (defaultValues != null) {
for (int i = Math.max(numPositionalArgs, numMandatoryPositionalParams);
i < numPositionalParams;
i++) {
if (arguments[i] == null) {
arguments[i] = defaultValues.get(i - numMandatoryPositionalParams);
}
}
int numMandatoryParams = numMandatoryPositionalParams + numMandatoryNamedOnlyParams;
for (int i = numMandatoryParams + numOptionalPositionalParams; i < numNamedParams; i++) {
if (arguments[i] == null) {
arguments[i] = defaultValues.get(i - numMandatoryParams);
}
}
}
} // End of general case 2c for argument passing.
return arguments;
}
