generic-library/ChaiScript
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Allow shorter form for loop with missing first param

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This commit is contained in:
Jonathan Turner
2009-06-08 15:30:02 +00:00
parent 5752ef0667
commit 50f60304f0
2 changed files with 28 additions and 8 deletions
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6
samples/for.wes
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@@ -5,3 +5,9 @@ for (var i = 0; i < 10; i += 1) {
for (i = 10; i >= 0; i -= 2) { for (i = 10; i >= 0; i -= 2) {
print(i) print(i)
} }
i = 0
for (; i < 5; i += 1) {
print(i)
}

30
wesley/main.cpp
View File

@@ -339,23 +339,37 @@ Boxed_Value eval_token(BoxedCPP_System &ss, TokenPtr node) {
case(TokenType::For_Block) : { case(TokenType::For_Block) : {
Boxed_Value condition; Boxed_Value condition;
bool cond; bool cond;
try { try {
eval_token(ss, node->children[0]); if (node->children.size() == 4) {
condition = eval_token(ss, node->children[1]); eval_token(ss, node->children[0]);
condition = eval_token(ss, node->children[1]);
}
else if (node->children.size() == 3){
condition = eval_token(ss, node->children[0]);
}
cond = Cast_Helper<bool &>()(condition); cond = Cast_Helper<bool &>()(condition);
} }
catch (std::exception) { catch (std::exception) {
throw EvalError("For condition not boolean", node->children[0]); throw EvalError("For condition not boolean", node);
} }
while (cond) { while (cond) {
eval_token(ss, node->children[3]);
try { try {
eval_token(ss, node->children[2]); if (node->children.size() == 4) {
condition = eval_token(ss, node->children[1]); eval_token(ss, node->children[3]);
eval_token(ss, node->children[2]);
condition = eval_token(ss, node->children[1]);
}
else if (node->children.size() == 3) {
eval_token(ss, node->children[2]);
eval_token(ss, node->children[1]);
condition = eval_token(ss, node->children[0]);
}
cond = Cast_Helper<bool &>()(condition); cond = Cast_Helper<bool &>()(condition);
} }
catch (std::exception) { catch (std::exception) {
throw EvalError("For condition not boolean", node->children[0]); throw EvalError("For condition not boolean", node);
} }
} }
retval = Boxed_Value(); retval = Boxed_Value();
@@ -433,7 +447,7 @@ Rule build_parser_rules() {
if_block = Ign(Str("if")) >> boolean >> block >> *(Str("elseif") >> boolean >> block) >> ~(Str("else") >> block); if_block = Ign(Str("if")) >> boolean >> block >> *(Str("elseif") >> boolean >> block) >> ~(Str("else") >> block);
while_block = Ign(Str("while")) >> boolean >> block; while_block = Ign(Str("while")) >> boolean >> block;
for_block = Ign(Str("for")) >> for_conditions >> 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)); 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))) >> fundef = Ign(Str("def")) >> Id(TokenType::Identifier) >> ~(Ign(Id(TokenType::Parens_Open)) >> ~params >> Ign(Id(TokenType::Parens_Close))) >>
block >> ~Ign(Id(TokenType::Semicolon)); block >> ~Ign(Id(TokenType::Semicolon));