@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);
}
}
protected boolean hasSelfArgument() {
Class<?> clazz = getObjectType();
if (clazz == null) {
return false;
}
List<SkylarkType> types = signature.getTypes();
ImmutableList<String> names = signature.getSignature().getNames();
return (!types.isEmpty() && types.get(0).canBeCastTo(clazz))
|| (!names.isEmpty() && names.get(0).equals("self"));
}
/** check types and convert as required */
protected void canonicalizeArguments(Object[] arguments, Location loc) throws EvalException {
// TODO(bazel-team): maybe link syntax.SkylarkType and package.Type,
// so we can simultaneously typecheck and convert?
// Note that a BuiltinFunction already does typechecking of simple types.
List<SkylarkType> types = getEnforcedArgumentTypes();
// Check types, if supplied
if (types == null) {
return;
}
List<String> names = signature.getSignature().getNames();
int length = types.size();
for (int i = 0; i < length; i++) {
Object value = arguments[i];
SkylarkType type = types.get(i);
if (value != null && type != null && !type.contains(value)) {
throw new EvalException(
loc,
String.format(
"expected %s for '%s' while calling %s but got %s instead: %s",
type, names.get(i), getName(), EvalUtils.getDataTypeName(value, true), value));
}
}
}
/**
* Returns the signature as "[className.]methodName(name1: paramType1, name2: paramType2, ...)" or
* "[className.]methodName(paramType1, paramType2, ...)", depending on the value of showNames.
*/
public String getShortSignature(boolean showNames) {
StringBuilder builder = new StringBuilder();
boolean hasSelf = hasSelfArgument();
builder.append(getFullName()).append("(");
signature.toStringBuilder(builder, showNames, false, false, hasSelf);
builder.append(")");
return builder.toString();
}
/** Render this object in the form of an equivalent Python function signature. */
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(getName());
if (signature != null) {
sb.append('(');
signature.toStringBuilder(sb);
sb.append(')');
} // if unconfigured, don't even output parentheses
return sb.toString();
}
@Override
void exec(Environment env) throws EvalException, InterruptedException {
List<Expression> defaultExpressions = signature.getDefaultValues();
ArrayList<Object> defaultValues = null;
ArrayList<SkylarkType> types = null;
if (defaultExpressions != null) {
defaultValues = new ArrayList<>(defaultExpressions.size());
for (Expression expr : defaultExpressions) {
defaultValues.add(expr.eval(env));
}
}
env.update(
ident.getName(),
new UserDefinedFunction(
ident,
FunctionSignature.WithValues.<Object, SkylarkType>create(
signature.getSignature(), defaultValues, types),
statements,
(SkylarkEnvironment) env));
}
protected MixedModeFunction(
String name,
Iterable<String> parameters,
int numMandatoryParameters,
boolean onlyNamedArguments,
Location location) {
super(name);
this.parameters = ImmutableList.copyOf(parameters);
this.numMandatoryParameters = numMandatoryParameters;
this.onlyNamedArguments = onlyNamedArguments;
this.location = location;
// Fake a signature from the above
this.signature =
FunctionSignature.WithValues.<Object, SkylarkType>create(
FunctionSignature.of(numMandatoryParameters, this.parameters.toArray(new String[0])));
}
/** 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;
}
@Override
public Object call(
List<Object> args, Map<String, Object> kwargs, FuncallExpression ast, Environment env)
throws EvalException, InterruptedException {
// ast is null when called from Java (as there's no Skylark call site).
Location loc = ast == null ? location : ast.getLocation();
if (onlyNamedArguments && !args.isEmpty()) {
throw new EvalException(loc, getSignature() + " does not accept positional arguments");
}
if (kwargs == null) {
kwargs = ImmutableMap.<String, Object>of();
}
int numParams = parameters.size();
int numArgs = args.size();
Object[] namedArguments = new Object[numParams];
// first, positional arguments:
if (numArgs > numParams) {
throw new EvalException(loc, "too many positional arguments in call to " + getSignature());
}
for (int ii = 0; ii < numArgs; ++ii) {
namedArguments[ii] = args.get(ii);
}
// TODO(bazel-team): here, support *varargs splicing
// second, keyword arguments:
for (Map.Entry<String, Object> entry : kwargs.entrySet()) {
String keyword = entry.getKey();
int pos = parameters.indexOf(keyword);
if (pos == -1) {
List<String> unexpected = listDifference(new ArrayList<>(kwargs.keySet()), parameters);
Collections.sort(unexpected); // issue stable error messages.
throw new EvalException(
loc,
"unexpected keyword"
+ (unexpected.size() > 1 ? "s" : "")
+ " '"
+ Joiner.on("', '").join(unexpected)
+ "' in call to "
+ getSignature());
} else {
if (namedArguments[pos] != null) {
throw new EvalException(
loc, getSignature() + " got multiple values for keyword argument '" + keyword + "'");
}
namedArguments[pos] = kwargs.get(keyword);
}
}
// third, check mandatory parameters:
for (int ii = 0; ii < numMandatoryParameters; ++ii) {
if (namedArguments[ii] == null) {
throw new EvalException(loc, getSignature() + " received insufficient arguments");
}
}
// fourth, fill in defaults from the signature, if any
List<Object> defaults = signature.getDefaultValues();
if (defaults != null) {
int jj = 0;
for (int ii = numMandatoryParameters; ii < numParams; ++ii) {
if (namedArguments[ii] == null) {
namedArguments[ii] = defaults.get(jj);
}
jj++;
}
}
try {
return call(namedArguments, ast, env);
} catch (ConversionException
| IllegalArgumentException
| IllegalStateException
| ClassCastException e) {
throw new EvalException(loc, e.getMessage());
}
}
/** Create a function using a signature without defaults */
public MixedModeFunction(String name, FunctionSignature signature) {
this(name, FunctionSignature.WithValues.<Object, SkylarkType>create(signature), null);
}
/** Configure a function based on its signature */
protected void configure() {
// this function is called after the signature was initialized
Preconditions.checkState(signature != null);
enforcedArgumentTypes = signature.getTypes();
}
/**
* 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;
}
/** The size of the array required by the callee. */
protected int getArgArraySize() {
return signature.getSignature().getShape().getArguments();
}
