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Defines the public interface for the Semantic Kernel
// Copyright (c) Microsoft. All rights reserved.
package com.microsoft.semantickernel.implementation.templateengine.tokenizer.blocks;
import com.microsoft.semantickernel.Kernel;
import com.microsoft.semantickernel.contextvariables.ContextVariable;
import com.microsoft.semantickernel.contextvariables.ContextVariableType;
import com.microsoft.semantickernel.contextvariables.ContextVariableTypes;
import com.microsoft.semantickernel.exceptions.SKException;
import com.microsoft.semantickernel.orchestration.FunctionResult;
import com.microsoft.semantickernel.orchestration.InvocationContext;
import com.microsoft.semantickernel.semanticfunctions.KernelFunctionArguments;
import com.microsoft.semantickernel.semanticfunctions.KernelFunctionMetadata;
import com.microsoft.semantickernel.templateengine.semantickernel.TemplateException;
import com.microsoft.semantickernel.templateengine.semantickernel.TemplateException.ErrorCodes;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import javax.annotation.Nullable;
import org.apache.commons.text.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import reactor.core.publisher.Mono;
/**
* Represents a code block.
*/
public final class CodeBlock extends Block implements CodeRendering {
private static final Logger LOGGER = LoggerFactory.getLogger(CodeBlock.class);
private final List tokens;
/**
* Initializes a new instance of the {@link CodeBlock} class.
*
* @param tokens The tokens.
* @param content The content.
*/
public CodeBlock(List tokens, String content) {
super(content, BlockTypes.CODE);
this.tokens = Collections.unmodifiableList(tokens);
}
@Override
public boolean isValid() {
Optional invalid = tokens.stream().filter(token -> !token.isValid()).findFirst();
if (invalid.isPresent()) {
LOGGER.error("Invalid block" + invalid.get().getContent());
return false;
}
if (!this.tokens.isEmpty() && this.tokens.get(0).getType() == BlockTypes.NAMED_ARG) {
LOGGER.error("Unexpected named argument found. Expected function name first.");
return false;
}
if (this.tokens.size() > 1 && !this.isValidFunctionCall()) {
return false;
}
return true;
}
private boolean isValidFunctionCall() {
if (this.tokens.get(0).getType() != BlockTypes.FUNCTION_ID) {
LOGGER.error("Unexpected second token found: " + tokens.get(1).getContent());
return false;
}
if (this.tokens.get(1).getType() != BlockTypes.VALUE &&
this.tokens.get(1).getType() != BlockTypes.VARIABLE &&
this.tokens.get(1).getType() != BlockTypes.NAMED_ARG) {
LOGGER.error(
"The first arg of a function must be a quoted string, variable or named argument");
return false;
}
for (int i = 2; i < this.tokens.size(); i++) {
if (this.tokens.get(i).getType() != BlockTypes.NAMED_ARG) {
LOGGER.error(
"Functions only support named arguments after the first argument. Argument " + i
+ " is not named.");
return false;
}
}
return true;
}
@Override
public Mono renderCodeAsync(
Kernel kernel,
@Nullable KernelFunctionArguments arguments,
@Nullable InvocationContext context) {
if (!this.isValid()) {
throw new TemplateException(ErrorCodes.SYNTAX_ERROR);
}
if (context == null) {
context = InvocationContext.builder().build();
}
switch (this.tokens.get(0).getType()) {
case VALUE:
case VARIABLE:
return Mono.just(
((TextRendering) this.tokens.get(0)).render(context.getContextVariableTypes(),
arguments));
case FUNCTION_ID:
return this
.renderFunctionCallAsync(
(FunctionIdBlock) this.tokens.get(0),
kernel,
arguments,
context,
context.getContextVariableTypes().getVariableTypeForClass(String.class))
.map(ContextVariable::getValue)
.map(StringEscapeUtils::escapeXml11);
case UNDEFINED:
case TEXT:
case CODE:
default:
throw new RuntimeException("Unknown type");
}
}
private Mono> renderFunctionCallAsync(
FunctionIdBlock fBlock,
Kernel kernel,
@Nullable KernelFunctionArguments arguments,
InvocationContext context,
ContextVariableType resultType) {
// If the code syntax is {{functionName $varName}} use $varName instead of $input
// If the code syntax is {{functionName 'value'}} use "value" instead of $input
if (this.tokens.size() > 1) {
//Cloning the original arguments to avoid side effects - arguments added to the original arguments collection as a result of rendering template variables.
arguments = this.enrichFunctionArguments(kernel, fBlock,
KernelFunctionArguments.builder().withVariables(arguments).build(),
context);
}
return kernel
.invokeAsync(
fBlock.getPluginName(),
fBlock.getFunctionName())
.withArguments(arguments)
.withResultType(resultType)
.map(FunctionResult::getResultVariable);
}
///
/// Adds function arguments. If the first argument is not a named argument, it is added to the arguments collection as the 'input' argument.
/// Additionally, for the prompt expression - {{MyPlugin.MyFunction p1=$v1}}, the value of the v1 variable will be resolved from the original arguments collection.
/// Then, the new argument, p1, will be added to the arguments.
///
/// Kernel instance.
/// Function block.
/// The prompt rendering arguments.
/// The function arguments.
/// Occurs when any argument other than the first is not a named argument.
private KernelFunctionArguments enrichFunctionArguments(
Kernel kernel,
FunctionIdBlock fBlock,
KernelFunctionArguments arguments,
@Nullable InvocationContext context) {
Block firstArg = this.tokens.get(1);
ContextVariableTypes types = context == null ? new ContextVariableTypes()
: context.getContextVariableTypes();
// Get the function metadata
KernelFunctionMetadata functionMetadata = kernel
.getFunction(fBlock.getPluginName(), fBlock.getFunctionName()).getMetadata();
// Check if the function has parameters to be set
if (functionMetadata.getParameters().isEmpty()) {
throw new SKException(
"Function " + fBlock.getPluginName() + "." + fBlock.getFunctionName()
+ " does not take any arguments but it is being called in the template with {this._tokens.Count - 1} arguments.");
}
String firstPositionalParameterName = null;
Object firstPositionalInputValue = null;
int namedArgsStartIndex = 1;
if (firstArg.getType() != BlockTypes.NAMED_ARG) {
// Gets the function first parameter name
firstPositionalParameterName = functionMetadata.getParameters().get(0).getName();
String contextVariableName = firstPositionalParameterName;
if (firstArg instanceof VarBlock) {
contextVariableName = ((VarBlock) firstArg).getName();
}
ContextVariable arg = arguments.get(contextVariableName);
Class desiredType = functionMetadata.getParameters().get(0).getTypeClass();
if (arg != null) {
try {
firstPositionalInputValue = ContextVariable.convert(arg, desiredType, types);
} catch (Exception e) {
// ignore
}
}
if (firstPositionalInputValue == null) {
firstPositionalInputValue = ((TextRendering) tokens.get(1)).render(types,
arguments);
firstPositionalInputValue = ContextVariable
.convert(
firstPositionalInputValue,
functionMetadata.getParameters().get(0).getTypeClass(),
types);
}
// Type check is avoided and marshalling is done by the function itself
if (firstPositionalInputValue == null) {
throw new SKException(
"Unexpected null value for first positional argument: " + tokens.get(1)
.getContent());
}
// Keep previous trust information when updating the input
arguments.put(
firstPositionalParameterName,
types.contextVariableOf(firstPositionalInputValue));
namedArgsStartIndex++;
}
for (int i = namedArgsStartIndex; i < this.tokens.size(); i++) {
// When casting fails because the block isn't a NamedArg, arg is null
if (!(this.tokens.get(i) instanceof NamedArgBlock)) {
throw new SKException("Unexpected first token type: {this._tokens[i].Type:G}");
}
NamedArgBlock arg = (NamedArgBlock) this.tokens.get(i);
// Check if the positional parameter clashes with a named parameter
if (firstPositionalParameterName != null &&
firstPositionalParameterName.equalsIgnoreCase(arg.getName())) {
throw new SKException(
"Ambiguity found as a named parameter '{arg.Name}' cannot be set for the first parameter when there is also a positional value: '{firstPositionalInputValue}' provided. Function: {fBlock.PluginName}.{fBlock.FunctionName}");
}
arguments.put(arg.getName(), types.contextVariableOf(arg.getValue(types, arguments)));
}
return arguments;
}
}