Skip to content

Commit

Permalink
Skylark: Implement string.index and string.rindex
Browse files Browse the repository at this point in the history 
--
MOS_MIGRATED_REVID=89294740
  • Loading branch information
@laurentlb @hanwen
laurentlb authored and hanwen committed Mar 24, 2015
1 parent d1c8061 commit 4e116c7
Showing 1 changed file with 77 additions and 32 deletions.
109 changes: 77 additions & 32 deletions src/main/java/com/google/devtools/build/lib/packages/MethodLibrary.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -200,6 +200,26 @@ public Object call(Object[] args, FuncallExpression ast, Environment env)
}
};

// Common implementation for find, rfind, index, rindex.
// forward is true iff we want to return the last matching index.
private static int stringFind(String functionName, boolean forward, Object[] args)
throws ConversionException {
String thiz = Type.STRING.convert(args[0], functionName + " operand");
String sub = Type.STRING.convert(args[1], functionName + " argument");
int start = 0;
if (args[2] != null) {
start = Type.INTEGER.convert(args[2], functionName + " argument");
}
int end = thiz.length();
if (args[3] != null) {
end = Type.INTEGER.convert(args[3], functionName + " argument");
}
String substr = getPythonSubstring(thiz, start, end);
int subpos = forward ? substr.indexOf(sub) : substr.lastIndexOf(sub);
start = getClampedIndex(start, thiz.length());
return subpos < 0 ? subpos : subpos + start;
}

@SkylarkBuiltin(name = "rfind", objectType = StringModule.class, returnType = Integer.class,
doc = "Returns the last index where <code>sub</code> is found, "
+ "or -1 if no such index exists, optionally restricting to "
Expand All @@ -213,21 +233,8 @@ public Object call(Object[] args, FuncallExpression ast, Environment env)
private static Function rfind =
new MixedModeFunction("rfind", ImmutableList.of("this", "sub", "start", "end"), 2, false) {
@Override
public Object call(Object[] args, FuncallExpression ast)
throws ConversionException {
String thiz = Type.STRING.convert(args[0], "'rfind' operand");
String sub = Type.STRING.convert(args[1], "'rfind' argument");
int start = 0;
if (args[2] != null) {
start = Type.INTEGER.convert(args[2], "'rfind' argument");
}
int end = thiz.length();
if (args[3] != null) {
end = Type.INTEGER.convert(args[3], "'rfind' argument");
}
int subpos = getPythonSubstring(thiz, start, end).lastIndexOf(sub);
start = getClampedIndex(start, thiz.length());
return subpos < 0 ? subpos : subpos + start;
public Object call(Object[] args, FuncallExpression ast) throws ConversionException {
return stringFind("rfind", false, args);
}
};

Expand All @@ -246,19 +253,55 @@ public Object call(Object[] args, FuncallExpression ast)
@Override
public Object call(Object[] args, FuncallExpression ast)
throws ConversionException {
String thiz = Type.STRING.convert(args[0], "'find' operand");
String sub = Type.STRING.convert(args[1], "'find' argument");
int start = 0;
if (args[2] != null) {
start = Type.INTEGER.convert(args[2], "'find' argument");
return stringFind("find", true, args);
}
};

@SkylarkBuiltin(name = "rindex", objectType = StringModule.class, returnType = Integer.class,
doc = "Returns the last index where <code>sub</code> is found, "
+ "or throw an error if no such index exists, optionally restricting to "
+ "[<code>start</code>:<code>end</code>], "
+ "<code>start</code> being inclusive and <code>end</code> being exclusive.",
mandatoryParams = {
@Param(name = "sub", type = String.class, doc = "The substring to find.")},
optionalParams = {
@Param(name = "start", type = Integer.class, doc = "Restrict to search from this position."),
@Param(name = "end", type = Integer.class, doc = "Restrict to search before this position.")})
private static Function rindex =
new MixedModeFunction("rindex", ImmutableList.of("this", "sub", "start", "end"), 2, false) {
@Override
public Object call(Object[] args, FuncallExpression ast)
throws EvalException, ConversionException {
int res = stringFind("rindex", false, args);
if (res < 0) {
throw new EvalException(ast.getLocation(),
"substring '" + args[1] + "' not found in '" + args[0] + "'");
}
int end = thiz.length();
if (args[3] != null) {
end = Type.INTEGER.convert(args[3], "'find' argument");
return res;
}
};

@SkylarkBuiltin(name = "index", objectType = StringModule.class, returnType = Integer.class,
doc = "Returns the first index where <code>sub</code> is found, "
+ "or throw an error if no such index exists, optionally restricting to "
+ "[<code>start</code>:<code>end]</code>, "
+ "<code>start</code> being inclusive and <code>end</code> being exclusive.",
mandatoryParams = {
@Param(name = "sub", type = String.class, doc = "The substring to find.")},
optionalParams = {
@Param(name = "start", type = Integer.class, doc = "Restrict to search from this position."),
@Param(name = "end", type = Integer.class, doc = "Restrict to search before this position.")})
private static Function index =
new MixedModeFunction("index", ImmutableList.of("this", "sub", "start", "end"), 2, false) {
@Override
public Object call(Object[] args, FuncallExpression ast)
throws EvalException, ConversionException {
int res = stringFind("index", true, args);
if (res < 0) {
throw new EvalException(ast.getLocation(),
"substring '" + args[1] + "' not found in '" + args[0] + "'");
}
int subpos = getPythonSubstring(thiz, start, end).indexOf(sub);
start = getClampedIndex(start, thiz.length());
return subpos < 0 ? subpos : subpos + start;
return res;
}
};

Expand Down Expand Up @@ -432,7 +475,7 @@ public Object call(Object[] args, FuncallExpression ast) throws EvalException,
@SkylarkBuiltin(name = "$index", hidden = true,
doc = "Returns the nth element of a list or string, "
+ "or looks up a value in a dictionary.")
private static Function index = new MixedModeFunction("$index",
private static Function indexOperator = new MixedModeFunction("$index",
ImmutableList.of("this", "index"), 2, false) {
@Override
public Object call(Object[] args, FuncallExpression ast) throws EvalException,
Expand Down Expand Up @@ -960,6 +1003,8 @@ public static final class DictModule {}
.put(split, SkylarkType.of(List.class, String.class))
.put(rfind, SkylarkType.INT)
.put(find, SkylarkType.INT)
.put(rindex, SkylarkType.INT)
.put(index, SkylarkType.INT)
.put(endswith, SkylarkType.BOOL)
.put(startswith, SkylarkType.BOOL)
.put(strip, SkylarkType.STRING)
Expand Down Expand Up @@ -1013,18 +1058,18 @@ public static final class DictModule {}
* Set up a given environment for supported class methods.
*/
public static void setupMethodEnvironment(Environment env) {
env.registerFunction(Map.class, index.getName(), index);
env.registerFunction(Map.class, indexOperator.getName(), indexOperator);
setupMethodEnvironment(env, Map.class, dictFunctions.keySet());
env.registerFunction(String.class, index.getName(), index);
env.registerFunction(String.class, indexOperator.getName(), indexOperator);
setupMethodEnvironment(env, String.class, stringFunctions.keySet());
setupMethodEnvironment(env, List.class, listPureFunctions.keySet());
setupMethodEnvironment(env, SkylarkList.class, listPureFunctions.keySet());
if (env.isSkylarkEnabled()) {
env.registerFunction(SkylarkList.class, index.getName(), index);
env.registerFunction(SkylarkList.class, indexOperator.getName(), indexOperator);
setupMethodEnvironment(env, skylarkGlobalFunctions.keySet());
} else {
env.registerFunction(List.class, index.getName(), index);
env.registerFunction(ImmutableList.class, index.getName(), index);
env.registerFunction(List.class, indexOperator.getName(), indexOperator);
env.registerFunction(ImmutableList.class, indexOperator.getName(), indexOperator);
// TODO(bazel-team): listFunctions are not allowed in Skylark extensions (use += instead).
// It is allowed in BUILD files only for backward-compatibility.
setupMethodEnvironment(env, List.class, listFunctions);
Expand Down

0 comments on commit 4e116c7

Please sign in to comment.