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Added break and return statements. Fixed inner block parsing

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This commit is contained in:
Jonathan Turner 2009-06-09 13:16:11 +00:00
parent dba0f3ed7a
commit 53c3e2ee25
3 changed files with 171 additions and 83 deletions
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8
langkit/main.cpp
View File

@ -95,6 +95,12 @@ void parse(std::vector<TokenPtr> &tokens, const char *filename) {
block = Ign(Str("{")) >> ~return_statement >> Ign(Str("}")); block = Ign(Str("{")) >> ~return_statement >> Ign(Str("}"));
return_statement = Ign(Str("return")) >> expression; return_statement = Ign(Str("return")) >> expression;
*/ */
Rule rule(TokenType::Equation);
rule = Str("break");
std::cout << "Check: " << rule.impl->new_id << std::endl;
/*
Rule rule = *(expression >> *Ign(Id(TokenType::Semicolon))); Rule rule = *(expression >> *Ign(Id(TokenType::Semicolon)));
expression = term >> *((Str("+") >> term) | (Str("-") >> term)); expression = term >> *((Str("+") >> term) | (Str("-") >> term));
term = factor >> *((Str("*") >> factor) | (Str("/") >> factor)); term = factor >> *((Str("*") >> factor) | (Str("/") >> factor));
@ -103,7 +109,7 @@ void parse(std::vector<TokenPtr> &tokens, const char *filename) {
negate = Ign(Str("-")) >> factor; negate = Ign(Str("-")) >> factor;
value = funcall | Id(TokenType::Identifier) | Id(TokenType::Number) | Id(TokenType::Quoted_String) | Id(TokenType::Single_Quoted_String); value = funcall | Id(TokenType::Identifier) | Id(TokenType::Number) | Id(TokenType::Quoted_String) | Id(TokenType::Single_Quoted_String);
*/
/* /*
Rule rule = Str("x") << Id(TokenType::Semicolon); Rule rule = Str("x") << Id(TokenType::Semicolon);
*/ */

20
samples/loop_break.wes Normal file
View File

@ -0,0 +1,20 @@
for (var i = 0; i < 10; ++i) {
print("i: " + i.to_string())
if (i == 5) {
break
}
}
var j = 0
while (true) {
while (true) {
++j;
if (j == 5) {
break
}
}
break
}
print("j: " + j.to_string())

226
wesley/main.cpp
View File

@ -17,14 +17,14 @@ class TokenType { public: enum Type { File, Whitespace, Identifier, Integer, Ope
Square_Open, Square_Close, Curly_Open, Curly_Close, Comma, Quoted_String, Single_Quoted_String, Carriage_Return, Semicolon, Square_Open, Square_Close, Curly_Open, Curly_Close, Comma, Quoted_String, Single_Quoted_String, Carriage_Return, Semicolon,
Function_Def, Scoped_Block, Statement, Equation, Return, Expression, Term, Factor, Negate, Comment, Function_Def, Scoped_Block, Statement, Equation, Return, Expression, Term, Factor, Negate, Comment,
Value, Fun_Call, Method_Call, Comparison, If_Block, While_Block, Boolean, Real_Number, Array_Call, Variable_Decl, Array_Init, Value, Fun_Call, Method_Call, Comparison, If_Block, While_Block, Boolean, Real_Number, Array_Call, Variable_Decl, Array_Init,
For_Block, Prefix }; }; For_Block, Prefix, Break }; };
const char *tokentype_to_string(int tokentype) { const char *tokentype_to_string(int tokentype) {
const char *token_types[] = {"File", "Whitespace", "Identifier", "Integer", "Operator", "Parens_Open", "Parens_Close", const char *token_types[] = {"File", "Whitespace", "Identifier", "Integer", "Operator", "Parens_Open", "Parens_Close",
"Square_Open", "Square_Close", "Curly_Open", "Curly_Close", "Comma", "Quoted_String", "Single_Quoted_String", "Carriage_Return", "Semicolon", "Square_Open", "Square_Close", "Curly_Open", "Curly_Close", "Comma", "Quoted_String", "Single_Quoted_String", "Carriage_Return", "Semicolon",
"Function_Def", "Scoped_Block", "Statement", "Equation", "Return", "Expression", "Term", "Factor", "Negate", "Comment", "Function_Def", "Scoped_Block", "Statement", "Equation", "Return", "Expression", "Term", "Factor", "Negate", "Comment",
"Value", "Fun_Call", "Method_Call", "Comparison", "If_Block", "While_Block", "Boolean", "Real Number", "Array_Call", "Variable_Decl", "Array_Init" "Value", "Fun_Call", "Method_Call", "Comparison", "If_Block", "While_Block", "Boolean", "Real Number", "Array_Call", "Variable_Decl", "Array_Init",
"For_Block", "Prefix" }; "For_Block", "Prefix", "Break" };
return token_types[tokentype]; return token_types[tokentype];
} }
@ -43,6 +43,19 @@ struct EvalError {
EvalError(const std::string &why, const TokenPtr where) : reason(why), location(where) { } EvalError(const std::string &why, const TokenPtr where) : reason(why), location(where) { }
}; };
struct ReturnValue {
Boxed_Value retval;
TokenPtr location;
ReturnValue(const Boxed_Value &return_value, const TokenPtr where) : retval(return_value), location(where) { }
};
struct BreakLoop {
TokenPtr location;
BreakLoop(const TokenPtr where) : location(where) { }
};
Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node); Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node);
Boxed_Value evaluate_string(Lexer &lexer, Rule &parser, BoxedCPP_System &ss, const std::string &input, const char *filename); Boxed_Value evaluate_string(Lexer &lexer, Rule &parser, BoxedCPP_System &ss, const std::string &input, const char *filename);
@ -129,73 +142,6 @@ const Boxed_Value eval_function (BoxedCPP_System &ss, TokenPtr node, const std::
return eval_token(ss, node); return eval_token(ss, node);
} }
Rule build_parser_rules() {
Rule params;
Rule block(TokenType::Scoped_Block);
Rule fundef(TokenType::Function_Def);
Rule statement;
Rule return_statement(TokenType::Return);
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 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 value;
Rule statements;
Rule for_conditions;
Rule rule = *((fundef | statements) >> *(Ign(Id(TokenType::Semicolon))));
statements = (statement >> *(Ign(Id(TokenType::Semicolon)) >> statement) >> *(Ign(Id(TokenType::Semicolon))));
statement = if_block | while_block | for_block | equation;
if_block = Ign(Str("if")) >> boolean >> block >> *(Str("elseif") >> boolean >> block) >> ~(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 >> ~Ign(Id(TokenType::Semicolon));
params = Id(TokenType::Identifier) >> *(Ign(Str(",")) >> Id(TokenType::Identifier));
block = *(Ign(Id(TokenType::Semicolon))) >> Ign(Id(TokenType::Curly_Open)) >> *(Ign(Id(TokenType::Semicolon))) >> ~statements >> Ign(Id(TokenType::Curly_Close)) >> *(Ign(Id(TokenType::Semicolon)));
equation = *(((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("+=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("-=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("*=")) |
((vardecl | arraycall | 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 | prefix | (Ign(Str("+")) >> value);
funcall = Id(TokenType::Identifier) >> Ign(Id(TokenType::Parens_Open)) >> ~(boolean >> *(Ign(Str("," )) >> boolean)) >> Ign(Id(TokenType::Parens_Close));
methodcall = value >> +(Ign(Str(".")) >> funcall);
negate = Ign(Str("-")) >> boolean;
prefix = (Str("++") >> (boolean | arraycall)) | (Str("--") >> (boolean | arraycall));
return_statement = Ign(Str("return")) >> boolean;
arraycall = value >> +((Ign(Id(TokenType::Square_Open)) >> boolean >> Ign(Id(TokenType::Square_Close))));
value = vardecl | arrayinit | block | (Ign(Id(TokenType::Parens_Open)) >> boolean >> Ign(Id(TokenType::Parens_Close))) | return_statement |
funcall | Id(TokenType::Identifier) | Id(TokenType::Real_Number) | Id(TokenType::Integer) | Id(TokenType::Quoted_String) |
Id(TokenType::Single_Quoted_String) ;
arrayinit = Ign(Id(TokenType::Square_Open)) >> ~(boolean >> *(Ign(Str(",")) >> boolean)) >> Ign(Id(TokenType::Square_Close));
vardecl = Ign(Str("var")) >> Id(TokenType::Identifier);
return rule;
}
Lexer build_lexer() { Lexer build_lexer() {
Lexer lexer; Lexer lexer;
lexer.set_skip(Pattern("[ \\t]+", TokenType::Whitespace)); lexer.set_skip(Pattern("[ \\t]+", TokenType::Whitespace));
@ -221,6 +167,77 @@ Lexer build_lexer() {
return lexer; return lexer;
} }
Rule build_parser_rules() {
Rule params;
Rule block(TokenType::Scoped_Block);
Rule fundef(TokenType::Function_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 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 return_statement(TokenType::Return);
Rule break_statement(TokenType::Break);
Rule value;
Rule statements;
Rule for_conditions;
Rule rule = *((fundef | statements) >> *(Ign(Id(TokenType::Semicolon))));
statements = *(statement >> *(Ign(Id(TokenType::Semicolon))));
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 >> ~Ign(Id(TokenType::Semicolon));
params = Id(TokenType::Identifier) >> *(Ign(Str(",")) >> Id(TokenType::Identifier));
block = *(Ign(Id(TokenType::Semicolon))) >> Ign(Id(TokenType::Curly_Open)) >> *(Ign(Id(TokenType::Semicolon))) >> ~statements >> Ign(Id(TokenType::Curly_Close));
equation = *(((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("+=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("-=")) |
((vardecl | arraycall | Id(TokenType::Identifier)) >> Str("*=")) |
((vardecl | arraycall | 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 | prefix | (Ign(Str("+")) >> value);
funcall = Id(TokenType::Identifier) >> Ign(Id(TokenType::Parens_Open)) >> ~(boolean >> *(Ign(Str("," )) >> boolean)) >> Ign(Id(TokenType::Parens_Close));
methodcall = value >> +(Ign(Str(".")) >> funcall);
negate = Ign(Str("-")) >> boolean;
prefix = (Str("++") >> (boolean | arraycall)) | (Str("--") >> (boolean | arraycall));
arraycall = value >> +((Ign(Id(TokenType::Square_Open)) >> boolean >> Ign(Id(TokenType::Square_Close))));
value = vardecl | arrayinit | block | (Ign(Id(TokenType::Parens_Open)) >> boolean >> Ign(Id(TokenType::Parens_Close))) | return_statement |
funcall | Id(TokenType::Identifier) | Id(TokenType::Real_Number) | Id(TokenType::Integer) | Id(TokenType::Quoted_String) |
Id(TokenType::Single_Quoted_String) ;
arrayinit = Ign(Id(TokenType::Square_Open)) >> ~(boolean >> *(Ign(Str(",")) >> boolean)) >> Ign(Id(TokenType::Square_Close));
vardecl = Ign(Str("var")) >> Id(TokenType::Identifier);
return_statement = Ign(Str("return")) >> ~boolean;
//break_statement = Ign(Str("break")) >> ~Ign(Id(TokenType::Semicolon));
return rule;
}
BoxedCPP_System build_eval_system(Lexer &lexer, Rule &parser) { BoxedCPP_System build_eval_system(Lexer &lexer, Rule &parser) {
BoxedCPP_System ss; BoxedCPP_System ss;
bootstrap(ss); bootstrap(ss);
@ -270,8 +287,17 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
else if (node->text == "false") { else if (node->text == "false") {
retval = Boxed_Value(false); retval = Boxed_Value(false);
} }
else if (node->text == "break") {
//todo: this is a WORKAROUND for parser combinator limitations
throw BreakLoop(node);
}
else { else {
retval = ss.get_object(node->text); try {
retval = ss.get_object(node->text);
}
catch (std::exception &e) {
throw EvalError("Can not find object: " + node->text, node);
}
} }
break; break;
case (TokenType::Real_Number) : case (TokenType::Real_Number) :
@ -408,6 +434,9 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
catch(std::exception &e){ catch(std::exception &e){
throw EvalError("Can not find appropriate '" + node->children[0]->text + "'", node->children[0]); throw EvalError("Can not find appropriate '" + node->children[0]->text + "'", node->children[0]);
} }
catch(ReturnValue &rv) {
retval = rv.retval;
}
} }
break; break;
case (TokenType::Method_Call) : { case (TokenType::Method_Call) : {
@ -424,9 +453,15 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
try { try {
retval = dispatch(ss.get_function(node->children[i]->children[0]->text), plb); retval = dispatch(ss.get_function(node->children[i]->children[0]->text), plb);
} }
catch(EvalError &ee) {
throw EvalError(ee.reason, node->children[0]);
}
catch(std::exception &e){ catch(std::exception &e){
throw EvalError("Can not find appropriate '" + node->children[i]->children[0]->text + "'", node->children[0]); throw EvalError("Can not find appropriate '" + node->children[i]->children[0]->text + "'", node->children[0]);
} }
catch(ReturnValue &rv) {
retval = rv.retval;
}
} }
} }
} }
@ -437,7 +472,7 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
try { try {
cond = Cast_Helper<bool &>()(retval); cond = Cast_Helper<bool &>()(retval);
} }
catch (std::exception) { catch (std::exception &e) {
throw EvalError("If condition not boolean", node->children[0]); throw EvalError("If condition not boolean", node->children[0]);
} }
if (cond) { if (cond) {
@ -456,7 +491,7 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
try { try {
cond = Cast_Helper<bool &>()(retval); cond = Cast_Helper<bool &>()(retval);
} }
catch (std::exception) { catch (std::exception &e) {
throw EvalError("Elseif condition not boolean", node->children[i+1]); throw EvalError("Elseif condition not boolean", node->children[i+1]);
} }
if (cond) { if (cond) {
@ -479,13 +514,18 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
throw EvalError("While condition not boolean", node->children[0]); throw EvalError("While condition not boolean", node->children[0]);
} }
while (cond) { while (cond) {
eval_token(ss, node->children[1]);
retval = eval_token(ss, node->children[0]);
try { try {
cond = Cast_Helper<bool &>()(retval); eval_token(ss, node->children[1]);
retval = eval_token(ss, node->children[0]);
try {
cond = Cast_Helper<bool &>()(retval);
}
catch (std::exception) {
throw EvalError("While condition not boolean", node->children[0]);
}
} }
catch (std::exception) { catch (BreakLoop &bl) {
throw EvalError("While condition not boolean", node->children[0]); cond = false;
} }
} }
retval = Boxed_Value(); retval = Boxed_Value();
@ -505,7 +545,7 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
} }
cond = Cast_Helper<bool &>()(condition); cond = Cast_Helper<bool &>()(condition);
} }
catch (std::exception) { catch (std::exception &e) {
throw EvalError("For condition not boolean", node); throw EvalError("For condition not boolean", node);
} }
while (cond) { while (cond) {
@ -523,9 +563,12 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
cond = Cast_Helper<bool &>()(condition); cond = Cast_Helper<bool &>()(condition);
} }
catch (std::exception) { catch (std::exception &e) {
throw EvalError("For condition not boolean", node); throw EvalError("For condition not boolean", node);
} }
catch (BreakLoop &bl) {
cond = false;
}
} }
retval = Boxed_Value(); retval = Boxed_Value();
} }
@ -549,8 +592,21 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
ss.pop_scope(); ss.pop_scope();
} }
break; break;
case (TokenType::Return) : {
if (node->children.size() > 0) {
retval = eval_token(ss, node->children[0]);
}
else {
retval = Boxed_Value();
}
throw ReturnValue(retval, node);
}
break;
case (TokenType::Break) : {
throw BreakLoop(node);
}
break;
case (TokenType::Statement) : case (TokenType::Statement) :
case (TokenType::Return) :
case (TokenType::Carriage_Return) : case (TokenType::Carriage_Return) :
case (TokenType::Semicolon) : case (TokenType::Semicolon) :
case (TokenType::Comment) : case (TokenType::Comment) :
@ -635,7 +691,13 @@ int main(int argc, char *argv[]) {
std::cout << "eval> "; std::cout << "eval> ";
std::getline(std::cin, input); std::getline(std::cin, input);
while (input != "quit") { while (input != "quit") {
Boxed_Value val = evaluate_string(lexer, parser, ss, input, "__EVAL__"); Boxed_Value val;
try {
val = evaluate_string(lexer, parser, ss, input, "__EVAL__");
}
catch (const ReturnValue &rv) {
val = rv.retval;
}
if (*(val.get_type_info().m_bare_type_info) != typeid(void)) { if (*(val.get_type_info().m_bare_type_info) != typeid(void)) {
try { try {
Boxed_Value printeval = dispatch(ss.get_function("to_string"), Param_List_Builder() << val); Boxed_Value printeval = dispatch(ss.get_function("to_string"), Param_List_Builder() << val);