/*
* Copyright (c) 2007 BUSINESS OBJECTS SOFTWARE LIMITED
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Business Objects nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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*/
/*
* LanguageInfo.java
* Creation date (Aug 21, 2002).
* By: Bo Ilic
*/
package org.openquark.cal.compiler;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
/**
* LanguageInfo is intended to contain helpful static methods describing the
* CAL language in general, independent of a particular run of the compiler
* on a particular project.
*
* Creation date (Aug 21, 2002).
* @author Bo Ilic
*/
public final class LanguageInfo {
/**
* Set<String> keywords in the CAL language.
* We duplicate this data from CALLexer so that standalone CAL jars do not need to
* load ANTLR.
*/
static final private Set<String> calKeywords = initializeCALKeywords();
/** Should be non-instantiable */
private LanguageInfo() {}
/**
* Returns true if the identifier is a lexically valid CAL module name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL module name.
*
* @see ModuleName#maybeMake(String)
*/
public static boolean isValidModuleName(String identifier) {
// if there are no dots in the identifier, then we can just validate it as a module name component
if (identifier.indexOf('.') < 0) {
return isValidModuleNameComponent(identifier);
} else {
// validate each component
String[] components = identifier.split("\\.");
for (int i = 0, n = components.length; i < n; i++) {
if (!isValidModuleNameComponent(components[i])) {
return false;
}
}
return true;
}
}
/**
* Returns an array of the components of the given module name after verifying that each one is
* a valid module name component.
* @param moduleName a module name.
* @return an array of the components of the given module name.
* @throws IllegalArgumentException if one or more of the components is not valid.
*/
public static String[] getVerifiedModuleNameComponents(String moduleName) {
if (moduleName == null) {
throw new NullPointerException();
}
if (moduleName.length() == 0) {
throw new IllegalArgumentException("The module name cannot be empty.");
}
String[] components = moduleName.split("\\.");
final int nComponents = components.length;
for (int i = 0; i < nComponents; i++) {
if (!isValidModuleNameComponent(components[i])) {
throw new IllegalArgumentException("'" + components[i] + "', occurring in the module name '" + moduleName + "' is not a valid module name component.");
}
}
return components;
}
/**
* Returns true if the identifier is a lexically valid CAL module name component.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL module name component.
*/
public static boolean isValidModuleNameComponent(String identifier) {
return isValidCons(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL function name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL function name.
*/
public static boolean isValidFunctionName(String identifier) {
return isValidVar(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL type constructor name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL type constructor name.
*/
public static boolean isValidTypeConstructorName(String identifier) {
return isValidCons(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL type variable name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL type variable name.
*/
public static boolean isValidTypeVariableName(String identifier) {
return isValidVar(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL data constructor name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL data constructor name.
*/
public static boolean isValidDataConstructorName (String identifier) {
return isValidCons(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL type class name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL type class name.
*/
public static boolean isValidTypeClassName(String identifier) {
return isValidCons(identifier);
}
/**
* Returns true if the identifier is a lexically valid CAL class method name.
* @param identifier
* @return boolean true if the identifier is a lexically valid CAL class method name.
*/
public static boolean isValidClassMethodName(String identifier) {
return isValidVar(identifier);
}
/**
* Returns True if the identifier is a lexically valid CAL field name i.e. the field names uses in
* records types or record values. For example, "#2", "orderDate" etc.
* @param identifier
* @return boolean
*/
public static boolean isValidFieldName(String identifier) {
return FieldName.isValidCalSourceForm(identifier);
}
/**
* Returns true if the identifier is a valid CAL CONS lexer token.
* This means that the identifier start with an ANSI upper case letter, and is
* followed by any number of ANSI alphabetic characters, digits, or the underscore,
* and is also not a built-in keyword.
* @param identifier
* @return boolean true if the identifier is a valid CAL CONS lexer token.
*/
private static boolean isValidCons(final String identifier) {
if (identifier == null) {
return false;
}
int len = identifier.length();
// if there are no characters, it's not valid!
if (len < 1) {
return false;
}
// check that the first letter is an upper-case letter
if (!isCALConsStart(identifier.charAt(0))) {
return false;
}
// only letters, digits and underscores are allowed in the rest of the name
for (int i = 1; i < len; i++) {
if (!isCALConsPart(identifier.charAt(i))) {
return false;
}
}
//we use the fact that all keywords in CAL start with a lowercase letter to skip this test.
//return !isKeyword(identifier);
return true;
}
/**
* Returns true if the identifier is a valid CAL VAR lexer token.
* This means that the identifier start with an ANSI lower case letter or an underscore, and is
* followed by any number of ANSI alphabetic characters, digits, or the underscore,
* and is also not a built-in keyword.
* @param identifier
* @return boolean true if the identifier is a valid CAL VAR lexer token.
*/
private static boolean isValidVar(final String identifier) {
//it would be nicer to delegate to the lexer, but it is a pain to
//trap skipped lexical tokens such as whitespace and comments.
if (identifier == null) {
return false;
}
int len = identifier.length();
// if there are no characters, it's not valid!
if (len < 1) {
return false;
}
// check that the first letter is a lower-case letter
if (!isCALVarStart(identifier.charAt(0))) {
return false;
}
// only letters, digits and underscores are allowed in the rest of the name
for (int i = 1; i < len; i++) {
if (!isCALVarPart(identifier.charAt(i))) {
return false;
}
}
return !isKeyword(identifier);
}
/**
* Method isCALConsStart.
* @param c character to test.
* @return boolean true if c is a valid first character in a CONS CAL lexer token.
*/
public static boolean isCALConsStart(char c) {
return c >= 'A' && c <= 'Z';
}
/**
* Method isCALConsPart.
* @param c character to test.
* @return boolean true if c is a valid character, beyond the first character, in a CONS CAL lexer token.
*/
public static boolean isCALConsPart(char c) {
return isCALVarPart(c);
}
/**
* Method isCALVarStart.
* @param c character to test.
* @return boolean true if c is a valid first character in a VAR CAL lexer token.
*/
public static boolean isCALVarStart(char c) {
return c >= 'a' && c <= 'z';
}
/**
* Method isCALVarPart.
* @param c character to test.
* @return boolean true if c is a valid character, beyond the first character, in a VAR CAL lexer token.
*/
public static boolean isCALVarPart(char c) {
return c >= 'a' && c <= 'z' ||
c >= 'A' && c <= 'Z' ||
c >= '0' && c <= '9' ||
c == '_';
}
/**
* Returns whether the character is lexically considered a whitespace character by CAL.
* @param ch the character to check.
* @return true if the character is lexically considered a whitespace character by CAL; false otherwise.
*/
public static boolean isCALWhitespace(char ch) {
switch (ch) {
case ' ':
case '\t':
case '\f':
case '\r':
case '\n':
return true;
default:
return false;
}
}
/**
* Tests if an identifier is a CAL keyword.
* @param identifier
* @return true if the identifier is a CAL keyword such as "data" or "if".
*/
public static boolean isKeyword(final String identifier) {
return calKeywords.contains(identifier);
}
/**
* @return String Set of keywords in the CAL language. The set is unmodifiable.
*/
public static Set<String> getCALKeywords() {
return calKeywords;
}
/**
* Initializes the CAL keywords.
* We duplicate this data from CALLexer so that standalone CAL jars do not need to
* load ANTLR.
* @return Set<String> keywords in CAL. An unmodifiable set.
*/
private static Set<String> initializeCALKeywords() {
Set<String> keywords = new HashSet<String>();
keywords.add("public");
keywords.add("case");
keywords.add("dataConstructor");
keywords.add("where");
keywords.add("then");
keywords.add("module");
keywords.add("using");
keywords.add("unsafe");
keywords.add("protected");
keywords.add("class");
keywords.add("friend");
keywords.add("jvm");
keywords.add("function");
keywords.add("foreign");
keywords.add("of");
keywords.add("if");
keywords.add("typeConstructor");
keywords.add("data");
keywords.add("private");
keywords.add("default");
keywords.add("primitive");
keywords.add("instance");
keywords.add("deriving");
keywords.add("typeClass");
keywords.add("else");
keywords.add("import");
keywords.add("in");
keywords.add("let");
return Collections.unmodifiableSet(keywords);
}
}