[go-nuts] Notes about forgetting commas in function arguments, and error messages

On Thursday, 14 February 2013 02:36:28 UTC, Brendan Tracey wrote:

I recently had some syntax erros in my code that were hard to track down
due (from a go perspective). I figured I would write the comments here so
they are potentially googleable.

The built-in types are not keywords, so you can define a variable called
"string" or "float64". This can be useful, but it can also lead to
confusing errors when you've forgotten commas in your function arguments.
For example, declaring the function:

func Foo(float64 float64) (float64){
var b float64 = 5.0
return b
}

returns the error " float64 is not a type ". This is because in the
declaration of the function, float64 is the name of a float64; to the
compiler it is like the function was declared as Foo(num float64).

Similarly, if you forget a comma in a function type, it may seem like
arguments are disappearing as in the first error of
http://play.golang.org/p/XOayR2L1ay , but it's just that the compiler
drops the identifiers in the function type when returning the error.


(to help googling)
int is not a type
string is not a type

On Wed, Feb 13, 2013 at 6:36 PM, Brendan Tracey wrote:

I recently had some syntax erros in my code that were hard to track down
due (from a go perspective). I figured I would write the comments here so
they are potentially googleable.

The built-in types are not keywords, so you can define a variable called
"string" or "float64". This can be useful, but it can also lead to
confusing errors when you've forgotten commas in your function arguments.
For example, declaring the function:

func Foo(float64 float64) (float64){
var b float64 = 5.0
return b
}

returns the error " float64 is not a type ". This is because in the
declaration of the function, float64 is the name of a float64; to the
compiler it is like the function was declared as Foo(num float64).

Similarly, if you forget a comma in a function type, it may seem like
arguments are disappearing as in the first error of
http://play.golang.org/p/XOayR2L1ay , but it's just that the compiler
drops the identifiers in the function type when returning the error.


(to help googling)
int is not a type
string is not a type

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On Thursday, February 14, 2013 at 4:36:28 AM UTC+2, Brendan Tracey wrote:

I recently had some syntax erros in my code that were hard to track down
due (from a go perspective). I figured I would write the comments here so
they are potentially googleable.

The built-in types are not keywords, so you can define a variable called
"string" or "float64". This can be useful, but it can also lead to
confusing errors when you've forgotten commas in your function arguments.
For example, declaring the function:

func Foo(float64 float64) (float64){
var b float64 = 5.0
return b
}

returns the error " float64 is not a type ". This is because in the
declaration of the function, float64 is the name of a float64; to the
compiler it is like the function was declared as Foo(num float64).

Similarly, if you forget a comma in a function type, it may seem like
arguments are disappearing as in the first error of
http://play.golang.org/p/XOayR2L1ay , but it's just that the compiler
drops the identifiers in the function type when returning the error.


(to help googling)
int is not a type
string is not a type