Simplify parameterList().

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This commit is contained in:
Bob Nystrom 2015-02-27 06:51:37 -08:00
parent 96ceaa528b
commit 5d116153dd
1 changed files with 31 additions and 37 deletions
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68
src/wren_compiler.c
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@ -1512,10 +1512,9 @@ static void validateNumParameters(Compiler* compiler, int numArgs)
}
}
// Parses the rest of a parameter list after the opening delimeter, and closed
// by [endToken]. Updates `arity` in [signature] with the number of parameters.
static void finishParameterList(Compiler* compiler, Signature* signature,
TokenType endToken)
// Parses the rest of a comma-separated parameter list after the opening
// delimeter. Updates `arity` in [signature] with the number of parameters.
static void finishParameterList(Compiler* compiler, Signature* signature)
{
do
{
@ -1526,35 +1525,6 @@ static void finishParameterList(Compiler* compiler, Signature* signature,
declareNamedVariable(compiler);
}
while (match(compiler, TOKEN_COMMA));
const char* message;
switch (endToken)
{
case TOKEN_RIGHT_PAREN: message = "Expect ')' after parameters."; break;
case TOKEN_RIGHT_BRACKET: message = "Expect ']' after parameters."; break;
case TOKEN_PIPE: message = "Expect '|' after parameters."; break;
default:
message = NULL;
UNREACHABLE();
}
consume(compiler, endToken, message);
}
// Parses an optional delimited parameter list. Updates `type` and `arity` in
// [signature] to match what was parsed.
static void parameterList(Compiler* compiler, Signature* signature,
TokenType startToken, TokenType endToken)
{
// The parameter list is optional.
if (!match(compiler, startToken)) return;
signature->type = SIG_METHOD;
// Allow empty parameter lists for methods.
if (endToken == TOKEN_RIGHT_PAREN && match(compiler, endToken)) return;
finishParameterList(compiler, signature, endToken);
}
// Gets the symbol for a method [name]. If [length] is 0, it will be calculated
@ -1705,7 +1675,14 @@ static void methodCall(Compiler* compiler, Code instruction,
// Make a dummy signature to track the arity.
Signature fnSignature;
fnSignature.arity = 0;
parameterList(&fnCompiler, &fnSignature, TOKEN_PIPE, TOKEN_PIPE);
// Parse the parameter list, if any.
if (match(compiler, TOKEN_PIPE))
{
finishParameterList(&fnCompiler, &fnSignature);
consume(compiler, TOKEN_PIPE, "Expect '|' after function parameters.");
}
fnCompiler.numParams = fnSignature.arity;
finishBody(&fnCompiler, false);
@ -2369,11 +2346,28 @@ void subscriptSignature(Compiler* compiler, Signature* signature)
signature->length = 0;
// Parse the parameters inside the subscript.
finishParameterList(compiler, signature, TOKEN_RIGHT_BRACKET);
finishParameterList(compiler, signature);
consume(compiler, TOKEN_RIGHT_BRACKET, "Expect ']' after parameters.");
maybeSetter(compiler, signature);
}
// Parses an optional parenthesized parameter list. Updates `type` and `arity`
// in [signature] to match what was parsed.
static void parameterList(Compiler* compiler, Signature* signature)
{
// The parameter list is optional.
if (!match(compiler, TOKEN_LEFT_PAREN)) return;
signature->type = SIG_METHOD;
// Allow an empty parameter list.
if (match(compiler, TOKEN_RIGHT_PAREN)) return;
finishParameterList(compiler, signature);
consume(compiler, TOKEN_RIGHT_PAREN, "Expect ')' after parameters.");
}
// Compiles a method signature for a named method or setter.
void namedSignature(Compiler* compiler, Signature* signature)
{
@ -2383,7 +2377,7 @@ void namedSignature(Compiler* compiler, Signature* signature)
if (maybeSetter(compiler, signature)) return;
// Regular named method with an optional parameter list.
parameterList(compiler, signature, TOKEN_LEFT_PAREN, TOKEN_RIGHT_PAREN);
parameterList(compiler, signature);
}
// Compiles a method signature for a constructor.
@ -2393,7 +2387,7 @@ void constructorSignature(Compiler* compiler, Signature* signature)
signature->type = SIG_GETTER;
// Add the parameters, if there are any.
parameterList(compiler, signature, TOKEN_LEFT_PAREN, TOKEN_RIGHT_PAREN);
parameterList(compiler, signature);
}
// This table defines all of the parsing rules for the prefix and infix