ChaiScript/chaiscript/chaiscript_engine.hpp

290 lines
14 KiB
C++

// This file is distributed under the BSD License.
// See LICENSE.TXT for details.
#ifndef CHAISCRIPT_ENGINE_HPP_
#define CHAISCRIPT_ENGINE_HPP_
#include <exception>
namespace chaiscript
{
template <typename Eval_Engine>
class ChaiScript_System {
langkit::Lexer lexer;
langkit::Rule parser;
Eval_Engine engine;
public:
ChaiScript_System() : lexer(build_lexer()), parser(build_parser_rules()), engine(build_eval_system(lexer, parser)) {
}
Eval_Engine &get_eval_engine() {
return engine;
}
const dispatchkit::Boxed_Value eval(const std::vector<dispatchkit::Boxed_Value> &vals) {
std::string val;
try {
val = dispatchkit::boxed_cast<std::string &>(vals[0]);
}
catch (EvalError &ee) {
throw EvalError("Can not evaluate string: " + val + " reason: " + ee.reason, langkit::TokenPtr());
}
catch (std::exception &e) {
throw EvalError("Can not evaluate string: " + val, langkit::TokenPtr());
}
return evaluate_string(val);
}
std::string load_file(const char *filename) {
std::ifstream infile (filename, std::ios::in | std::ios::ate);
if (!infile.is_open()) {
std::string fname = filename;
throw std::runtime_error("Can not open: " + fname);
}
std::streampos size = infile.tellg();
infile.seekg(0, std::ios::beg);
std::vector<char> v(size);
infile.read(&v[0], size);
std::string ret_val (v.empty() ? std::string() : std::string (v.begin(), v.end()).c_str());
return ret_val;
}
void debug_print(langkit::TokenPtr token, std::string prepend) {
using namespace langkit;
std::cout << prepend << "Token: " << token->text << "(" << tokentype_to_string(token->identifier) << ") @ " << token->filename
<< ": (" << token->start.line << ", " << token->start.column << ") to ("
<< token->end.line << ", " << token->end.column << ") " << std::endl;
for (unsigned int i = 0; i < token->children.size(); ++i) {
debug_print(token->children[i], prepend + " ");
}
}
void debug_print(std::vector<langkit::TokenPtr> &tokens) {
using namespace langkit;
for (unsigned int i = 0; i < tokens.size(); ++i) {
debug_print(tokens[i], "");
}
}
langkit::Lexer build_lexer() {
using namespace langkit;
Lexer lexer;
lexer.set_skip(Pattern("[ \\t]+", TokenType::Whitespace));
lexer.set_line_sep(Pattern("\\n|\\r\\n", TokenType::Carriage_Return));
lexer.set_command_sep(Pattern(";|\\r\\n|\\n", TokenType::Semicolon));
lexer.set_multiline_comment(Pattern("/\\*", TokenType::Comment), Pattern("\\*/", TokenType::Comment));
lexer.set_singleline_comment(Pattern("//", TokenType::Comment));
lexer << Pattern("[A-Za-z_][A-Za-z_0-9]*", TokenType::Identifier);
lexer << Pattern("[0-9]+\\.[0-9]+", TokenType::Real_Number);
lexer << Pattern("[0-9]+", TokenType::Integer);
lexer << Pattern("[!@#$%^&*|\\-+=<>.:]+|/[!@#$%^&|\\-+=<>]*", TokenType::Operator);
lexer << Pattern("\\(", TokenType::Parens_Open);
lexer << Pattern("\\)", TokenType::Parens_Close);
lexer << Pattern("\\[", TokenType::Square_Open);
lexer << Pattern("\\]", TokenType::Square_Close);
lexer << Pattern("\\{", TokenType::Curly_Open);
lexer << Pattern("\\}", TokenType::Curly_Close);
lexer << Pattern(",", TokenType::Comma);
lexer << Pattern("\"(?:[^\"\\\\]|\\\\.)*\"", TokenType::Quoted_String);
lexer << Pattern("'(?:[^'\\\\]|\\\\.)*'", TokenType::Single_Quoted_String);
return lexer;
}
langkit::Rule build_parser_rules() {
using namespace langkit;
Rule params;
Rule block(TokenType::Scoped_Block);
Rule fundef(TokenType::Function_Def);
Rule lambda_def(TokenType::Lambda_Def);
Rule statement;
Rule equation(TokenType::Equation);
Rule boolean(TokenType::Boolean);
Rule comparison(TokenType::Comparison);
Rule expression(TokenType::Expression);
Rule term(TokenType::Term);
Rule factor(TokenType::Factor);
Rule negate(TokenType::Negate);
Rule boolean_not(TokenType::Not);
Rule prefix(TokenType::Prefix);
Rule funcall(TokenType::Fun_Call);
Rule methodcall(TokenType::Method_Call);
Rule if_block(TokenType::If_Block);
Rule while_block(TokenType::While_Block);
Rule for_block(TokenType::For_Block);
Rule arraycall(TokenType::Array_Call);
Rule vardecl(TokenType::Variable_Decl);
Rule arrayinit(TokenType::Array_Init);
Rule mapinit(TokenType::Map_Init);
Rule mappair(TokenType::Map_Pair);
Rule return_statement(TokenType::Return);
Rule break_statement(TokenType::Break);
Rule value;
Rule statements;
Rule for_conditions;
Rule source_elem;
Rule source_elems;
Rule statement_list;
Rule paren_block;
Rule rule = *(Ign(Id(TokenType::Semicolon))) >> source_elems >> *(Ign(Id(TokenType::Semicolon)));
source_elems = source_elem >> *(+Ign(Id(TokenType::Semicolon)) >> source_elem);
source_elem = fundef | statement;
statement_list = statement >> *(+Ign(Id(TokenType::Semicolon)) >> statement);
statement = if_block | while_block | for_block | equation;
if_block = Ign(Str("if")) >> boolean >> block >> *(*Ign(Id(TokenType::Semicolon)) >> Str("elseif") >> boolean >> block) >> ~(*Ign(Id(TokenType::Semicolon)) >> Str("else") >> block);
while_block = Ign(Str("while")) >> boolean >> block;
for_block = Ign(Str("for")) >> for_conditions >> block;
for_conditions = Ign(Id(TokenType::Parens_Open)) >> ~equation >> Ign(Str(";")) >> boolean >> Ign(Str(";")) >> equation >> Ign(Id(TokenType::Parens_Close));
fundef = Ign(Str("def")) >> Id(TokenType::Identifier) >> ~(Ign(Id(TokenType::Parens_Open)) >> ~params >> Ign(Id(TokenType::Parens_Close))) >>
block;
params = Id(TokenType::Identifier) >> *(Ign(Str(",")) >> Id(TokenType::Identifier));
block = *(Ign(Id(TokenType::Semicolon))) >> Ign(Id(TokenType::Curly_Open)) >> *(Ign(Id(TokenType::Semicolon))) >> ~statement_list >> *(Ign(Id(TokenType::Semicolon))) >> Ign(Id(TokenType::Curly_Close));
equation = *(((vardecl | arraycall | funcall | methodcall | Id(TokenType::Identifier)) >> Str("=")) |
((vardecl | arraycall | funcall | methodcall | Id(TokenType::Identifier)) >> Str("+=")) |
((vardecl | arraycall | funcall | methodcall | Id(TokenType::Identifier)) >> Str("-=")) |
((vardecl | arraycall | funcall | methodcall | Id(TokenType::Identifier)) >> Str("*=")) |
((vardecl | arraycall | funcall | methodcall | Id(TokenType::Identifier)) >> Str("/="))) >> boolean;
boolean = comparison >> *((Str("&&") >> comparison) | (Str("||") >> comparison));
comparison = expression >> *((Str("==") >> expression) | (Str("!=") >> expression) | (Str("<") >> expression) |
(Str("<=") >> expression) |(Str(">") >> expression) | (Str(">=") >> expression));
expression = term >> *((Str("+") >> term) | (Str("-") >> term));
term = factor >> *((Str("*") >> factor) | (Str("/") >> factor));
factor = methodcall | arraycall | value | negate | boolean_not | prefix | (Ign(Str("+")) >> value);
value = vardecl | mapinit | arrayinit | block | lambda_def | paren_block | return_statement | break_statement |
funcall | Id(TokenType::Identifier) | Id(TokenType::Real_Number) | Id(TokenType::Integer) | Id(TokenType::Quoted_String) |
Id(TokenType::Single_Quoted_String) ;
funcall = Id(TokenType::Identifier) >> Ign(Id(TokenType::Parens_Open)) >> ~(boolean >> *(Ign(Str("," )) >> boolean)) >> Ign(Id(TokenType::Parens_Close));
methodcall = value >> +(Ign(Str(".")) >> (funcall | Id(TokenType::Identifier)));
negate = (Str("-") >> (boolean | arraycall));
boolean_not = (Str("!") >> (boolean | arraycall));
prefix = (Str("++") >> (boolean | arraycall)) | (Str("--") >> (boolean | arraycall));
arraycall = value >> +((Ign(Id(TokenType::Square_Open)) >> boolean >> Ign(Id(TokenType::Square_Close))));
arrayinit = Ign(Id(TokenType::Square_Open)) >> ~(boolean >> *(Ign(Str(",")) >> boolean)) >> Ign(Id(TokenType::Square_Close));
mapinit = Ign(Id(TokenType::Square_Open)) >> ~(mappair >> *(Ign(Str(",")) >> mappair)) >> Ign(Id(TokenType::Square_Close));
mappair = Id(TokenType::Quoted_String) >> Ign(Str(":")) >> boolean;
vardecl = Ign(Str("var")) >> Id(TokenType::Identifier);
return_statement = Ign(Str("return")) >> ~boolean;
break_statement = Wrap(Ign(Str("break")));
paren_block = (Ign(Id(TokenType::Parens_Open)) >> equation >> Ign(Id(TokenType::Parens_Close)));
lambda_def = (Ign(Str("function")) >> ~(Ign(Id(TokenType::Parens_Open)) >> ~params >> Ign(Id(TokenType::Parens_Close))) >> block) |
(Ign(Id(TokenType::Parens_Open)) >> ~params >> Ign(Id(TokenType::Parens_Close)) >> Ign(Str(":")) >> block);
return rule;
}
Eval_Engine build_eval_system(langkit::Lexer &lexer, langkit::Rule &parser) {
using namespace langkit;
Eval_Engine ss;
dispatchkit::Bootstrap::bootstrap(ss);
dispatchkit::bootstrap_vector<std::vector<dispatchkit::Boxed_Value> >(ss, "Vector");
dispatchkit::bootstrap_map<std::map<std::string, dispatchkit::Boxed_Value> >(ss, "Map");
dispatchkit::bootstrap_pair<std::pair<dispatchkit::Boxed_Value, dispatchkit::Boxed_Value > >(ss, "Pair");
ss.register_function(boost::shared_ptr<dispatchkit::Proxy_Function>(
new dispatchkit::Dynamic_Proxy_Function(boost::bind(&ChaiScript_System<Eval_Engine>::eval, boost::ref(*this), _1), 1)), "eval");
evaluate_string("def print(x) { print_string(x.to_string()) }; "
"def for_each(container, func) { var range = range(container); while (!range.empty()) { func(range.front()); range.popFront();} }; "
"def map(container, func) { var retval = Vector(); var range = range(container); while (!range.empty()) { retval.push_back(func(range.front())); range.popFront();}; return retval;}; "
"def reduce(container, func, initial) { var retval = initial; var range = range(container); while (!range.empty()) { retval = (func(range.front(), retval)); range.popFront();}; return retval;}");
return ss;
}
langkit::TokenPtr parse(langkit::Rule &rule, std::vector<langkit::TokenPtr> &tokens, const char *filename) {
using namespace langkit;
Token_Iterator iter = tokens.begin(), end = tokens.end();
TokenPtr parent(new Token("Root", TokenType::File, filename));
std::pair<Token_Iterator, bool> results = rule(iter, end, parent);
if ((results.second) && (results.first == end)) {
//debug_print(parent, "");
return parent;
}
else {
throw ParserError("Parse failed to complete", *(results.first));
//throw ParserError("Parse failed to complete at: " + (*(results.first))->text , *(results.first));
}
}
dispatchkit::Boxed_Value evaluate_string(const std::string &input, const char *filename = "__EVAL__") {
using namespace langkit;
std::vector<TokenPtr> tokens = lexer.lex(input, filename);
dispatchkit::Boxed_Value value;
for (unsigned int i = 0; i < tokens.size(); ++i) {
if ((tokens[i]->identifier == TokenType::Quoted_String) || (tokens[i]->identifier == TokenType::Single_Quoted_String)) {
tokens[i]->text = tokens[i]->text.substr(1, tokens[i]->text.size()-2);
for (unsigned int j = 0; j < tokens[i]->text.size(); ++j) {
if (tokens[i]->text[j] == '\\') {
tokens[i]->text.erase(tokens[i]->text.begin() + j, tokens[i]->text.begin() + j + 1);
}
}
}
}
//debug_print(tokens);
try {
TokenPtr parent = parse(parser, tokens, filename);
value = eval_token<Eval_Engine>(engine, parent);
}
catch (const ReturnValue &rv) {
value = rv.retval;
}
catch (ParserError &pe) {
if (filename != std::string("__EVAL__")) {
std::cout << "Parsing error: \"" << pe.reason << "\" in '" << pe.location->filename << "' line: " << pe.location->start.line+1 << std::endl;
}
else {
std::cout << "Parsing error: \"" << pe.reason << "\"" << std::endl;
}
}
catch (EvalError &ee) {
if (filename != std::string("__EVAL__")) {
std::cout << "Eval error: \"" << ee.reason << "\" in '" << ee.location->filename << "' line: " << ee.location->start.line+1 << std::endl;
}
else {
std::cout << "Eval error: \"" << ee.reason << "\"" << std::endl;
}
}
catch (std::exception &e) {
std::cout << "Exception: " << e.what() << std::endl;
}
return value;
}
dispatchkit::Boxed_Value evaluate_file(const char *filename) {
return evaluate_string(load_file(filename), filename);
}
};
typedef ChaiScript_System<dispatchkit::Dispatch_Engine> ChaiScript_Engine;
}
#endif /* CHAISCRIPT_ENGINE_HPP_ */