function with if; case statement;
I've got two basic questions.
Is there any way to make a function in openScad which isn't a straight
formula? For instance the input parameter is a number and inside the
function I use a series of if statements to check the value and decide what
to return (alternately maybe the input parameter could pick a hardcoded
value out of a list??? But I don't know the proper syntax for that).
Likewise, is there any plan to support a "case" statement type construct,
either in functions or modules?
Use the ternary operator: https://en.wikipedia.org/wiki/%3F:
From: Dan Shriver tabbydan@gmail.com tabbydan@gmail.com
Reply: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Date: November 2, 2016 at 16:11:54
To: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Subject: [OpenSCAD] function with if; case statement;
I've got two basic questions.
Is there any way to make a function in openScad which isn't a straight
formula? For instance the input parameter is a number and inside the
function I use a series of if statements to check the value and decide what
to return (alternately maybe the input parameter could pick a hardcoded
value out of a list??? But I don't know the proper syntax for that).
Likewise, is there any plan to support a "case" statement type construct,
either in functions or modules?
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
terniary operator can only return two possible values so I don't see how
that can help with the current problem, unless the openscad "?" is
different from the one I'm used to
If I need to return one of n different values can I chain "?"
(x == 1) ? 5 : (x == 2) ? 7 : (x == 3) ? 4 ....
On Wed, Nov 2, 2016 at 7:24 PM, Whosawhatsis whosawhatsis@gmail.com wrote:
Use the ternary operator: https://en.wikipedia.org/wiki/%3F:
From: Dan Shriver tabbydan@gmail.com tabbydan@gmail.com
Reply: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Date: November 2, 2016 at 16:11:54
To: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Subject: [OpenSCAD] function with if; case statement;
I've got two basic questions.
Is there any way to make a function in openScad which isn't a straight
formula? For instance the input parameter is a number and inside the
function I use a series of if statements to check the value and decide what
to return (alternately maybe the input parameter could pick a hardcoded
value out of a list??? But I don't know the proper syntax for that).
Likewise, is there any plan to support a "case" statement type construct,
either in functions or modules?
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Functions only consist of expressions so you need to use the ternary
conditional operator. E.g.
function f(x) = x == 1 ? 42
: x == 2 ? 99 : 0;
This returns 42 when x is 1, 99 when x = 2 otherwise 0.
On 2 November 2016 at 23:11, Dan Shriver tabbydan@gmail.com wrote:
I've got two basic questions.
Is there any way to make a function in openScad which isn't a straight
formula? For instance the input parameter is a number and inside the
function I use a series of if statements to check the value and decide what
to return (alternately maybe the input parameter could pick a hardcoded
value out of a list??? But I don't know the proper syntax for that).
Likewise, is there any plan to support a "case" statement type construct,
either in functions or modules?
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
I often chain them but put them in a structural format:
function f(x)=
(
x==1?
x+1
: x==2 ?
let(y=3) x*y // you can use let
: x==3?
let( x=100, y=10 ) // you can even re defined x locally
x+y+y
: x
);
echo(f(1)); // = 2
echo(f(2)); // = 6
echo(f(3)); // = 120
echo(f(30)); // =30
You can come up with very complex content but still easily readable if empty
lines are inserted:
function f(x)=
(
x==1?
let(...)
(
......
......
)
: x==2 ?
let(...)
(
......
......
)
: x==3?
let(...)
(
......
......
)
: x
);
$ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ), runscad.py ( 2 , git ), synwrite ( 2 ); $ tips: hash ( 2 ), matrix ( 2 , 3 ), sweep ( 2 , 3 ), var ( 2 ), lerp , animation ( gif , prodVid , animlib ), precision ( 2 ), xl-control , type , rounded polygon , chfont , tailRecur ( 2, 3 ), isosphere ( 2 ), area , vol/center , RGB , CurvedImg , tests ( 2 ); $ Apps: rollApp , blockscad , openjscad , on AWS ( pdf )
View this message in context: http://forum.openscad.org/function-with-if-case-statement-tp18882p18890.html
Sent from the OpenSCAD mailing list archive at Nabble.com.
thaks whosawhatsis, nophead, runsun....
I tried that with several syntaxes and kept getting parse errors. Do I
need a special version of openScad to get the chained "?"?
Every time I try it (with and without "(" ");"; with and without readable
whitespace; with and without () around the testing) I get parsing errors.
On Wed, Nov 2, 2016 at 8:17 PM, runsun runsun@gmail.com wrote:
I often chain them but put them in a structural format:
function f(x)=
(
x==1?
x+1
: x==2 ?
let(y=3) x*y // you can use let
: x==3?
let( x=100, y=10 ) // you can even re defined x locally
x+y+y
: x
);
echo(f(1)); // = 2
echo(f(2)); // = 6
echo(f(3)); // = 120
echo(f(30)); // =30
You can come up with very complex content but still easily readable if
empty
lines are inserted:
function f(x)=
(
x==1?
let(...)
(
......
......
)
: x==2 ?
let(...)
(
......
......
)
: x==3?
let(...)
(
......
......
)
: x
);
$ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ),
runscad.py ( 2 , git ), synwrite ( 2 ); $ tips: hash ( 2 ), matrix (
2 , 3 ), sweep ( 2 , 3 ), var ( 2 ), lerp , animation ( gif , prodVid ,
animlib ), precision ( 2 ), xl-control , type , rounded polygon , chfont ,
tailRecur ( 2, 3 ), isosphere ( 2 ), area , vol/center , RGB , CurvedImg ,
tests ( 2 ); $ Apps: rollApp , blockscad , openjscad , on AWS ( pdf )
View this message in context: http://forum.openscad.org/
function-with-if-case-statement-tp18882p18890.html
Sent from the OpenSCAD mailing list archive at Nabble.com.
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Should work in any version. If you post what you tried to write, one of us
will be able to see what's wrong with it.
From: Dan Shriver tabbydan@gmail.com tabbydan@gmail.com
Reply: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Date: November 2, 2016 at 17:49:29
To: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Subject: Re: [OpenSCAD] function with if; case statement;
thaks whosawhatsis, nophead, runsun....
I tried that with several syntaxes and kept getting parse errors. Do I
need a special version of openScad to get the chained "?"?
Every time I try it (with and without "(" ");"; with and without readable
whitespace; with and without () around the testing) I get parsing errors.
On Wed, Nov 2, 2016 at 8:17 PM, runsun runsun@gmail.com wrote:
I often chain them but put them in a structural format:
function f(x)=
(
x==1?
x+1
: x==2 ?
let(y=3) x*y // you can use let
: x==3?
let( x=100, y=10 ) // you can even re defined x locally
x+y+y
: x
);
echo(f(1)); // = 2
echo(f(2)); // = 6
echo(f(3)); // = 120
echo(f(30)); // =30
You can come up with very complex content but still easily readable if
empty
lines are inserted:
function f(x)=
(
x==1?
let(...)
(
......
......
)
: x==2 ?
let(...)
(
......
......
)
: x==3?
let(...)
(
......
......
)
: x
);
$ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ),
runscad.py ( 2 , git ), synwrite ( 2 ); $ tips: hash ( 2 ), matrix (
2 , 3 ), sweep ( 2 , 3 ), var ( 2 ), lerp , animation ( gif , prodVid ,
animlib ), precision ( 2 ), xl-control , type , rounded polygon , chfont ,
tailRecur ( 2, 3 ), isosphere ( 2 ), area , vol/center , RGB , CurvedImg ,
tests ( 2 ); $ Apps: rollApp , blockscad , openjscad , on AWS ( pdf )
View this message in context: http://forum.openscad.org/
function-with-if-case-statement-tp18882p18890.html
Sent from the OpenSCAD mailing list archive at Nabble.com.
OpenSCAD mailing list
Discuss@lists.openscad.org
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whosawhatsis... yeah, digging into it, it is a bug somewhere in my code. I
already ferreted out one but obviously there is some more.
If I post the whole thing (because maybe it is in some line (as in any
line) above the one it flags) I think one or more of you guys will go blind
:(
On Wed, Nov 2, 2016 at 8:57 PM, Whosawhatsis whosawhatsis@gmail.com wrote:
Should work in any version. If you post what you tried to write, one of us
will be able to see what's wrong with it.
From: Dan Shriver tabbydan@gmail.com tabbydan@gmail.com
Reply: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Date: November 2, 2016 at 17:49:29
To: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Subject: Re: [OpenSCAD] function with if; case statement;
thaks whosawhatsis, nophead, runsun....
I tried that with several syntaxes and kept getting parse errors. Do I
need a special version of openScad to get the chained "?"?
Every time I try it (with and without "(" ");"; with and without readable
whitespace; with and without () around the testing) I get parsing errors.
On Wed, Nov 2, 2016 at 8:17 PM, runsun runsun@gmail.com wrote:
I often chain them but put them in a structural format:
function f(x)=
(
x==1?
x+1
: x==2 ?
let(y=3) x*y // you can use let
: x==3?
let( x=100, y=10 ) // you can even re defined x locally
x+y+y
: x
);
echo(f(1)); // = 2
echo(f(2)); // = 6
echo(f(3)); // = 120
echo(f(30)); // =30
You can come up with very complex content but still easily readable if
empty
lines are inserted:
function f(x)=
(
x==1?
let(...)
(
......
......
)
: x==2 ?
let(...)
(
......
......
)
: x==3?
let(...)
(
......
......
)
: x
);
$ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ),
runscad.py ( 2 , git ), synwrite ( 2 ); $ tips: hash ( 2 ), matrix (
2 , 3 ), sweep ( 2 , 3 ), var ( 2 ), lerp , animation ( gif , prodVid ,
animlib ), precision ( 2 ), xl-control , type , rounded polygon , chfont ,
tailRecur ( 2, 3 ), isosphere ( 2 ), area , vol/center , RGB , CurvedImg ,
tests ( 2 ); $ Apps: rollApp , blockscad , openjscad , on AWS ( pdf )
View this message in context: http://forum.openscad.org/func
tion-with-if-case-statement-tp18882p18890.html
Sent from the OpenSCAD mailing list archive at Nabble.com.
OpenSCAD mailing list
Discuss@lists.openscad.org
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[image: Inline image 1]
thanks guys!
On Wed, Nov 2, 2016 at 8:57 PM, Whosawhatsis whosawhatsis@gmail.com wrote:
Should work in any version. If you post what you tried to write, one of us
will be able to see what's wrong with it.
From: Dan Shriver tabbydan@gmail.com tabbydan@gmail.com
Reply: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Date: November 2, 2016 at 17:49:29
To: OpenSCAD general discussion discuss@lists.openscad.org
discuss@lists.openscad.org
Subject: Re: [OpenSCAD] function with if; case statement;
thaks whosawhatsis, nophead, runsun....
I tried that with several syntaxes and kept getting parse errors. Do I
need a special version of openScad to get the chained "?"?
Every time I try it (with and without "(" ");"; with and without readable
whitespace; with and without () around the testing) I get parsing errors.
On Wed, Nov 2, 2016 at 8:17 PM, runsun runsun@gmail.com wrote:
I often chain them but put them in a structural format:
function f(x)=
(
x==1?
x+1
: x==2 ?
let(y=3) x*y // you can use let
: x==3?
let( x=100, y=10 ) // you can even re defined x locally
x+y+y
: x
);
echo(f(1)); // = 2
echo(f(2)); // = 6
echo(f(3)); // = 120
echo(f(30)); // =30
You can come up with very complex content but still easily readable if
empty
lines are inserted:
function f(x)=
(
x==1?
let(...)
(
......
......
)
: x==2 ?
let(...)
(
......
......
)
: x==3?
let(...)
(
......
......
)
: x
);
$ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ),
runscad.py ( 2 , git ), synwrite ( 2 ); $ tips: hash ( 2 ), matrix (
2 , 3 ), sweep ( 2 , 3 ), var ( 2 ), lerp , animation ( gif , prodVid ,
animlib ), precision ( 2 ), xl-control , type , rounded polygon , chfont ,
tailRecur ( 2, 3 ), isosphere ( 2 ), area , vol/center , RGB , CurvedImg ,
tests ( 2 ); $ Apps: rollApp , blockscad , openjscad , on AWS ( pdf )
View this message in context: http://forum.openscad.org/func
tion-with-if-case-statement-tp18882p18890.html
Sent from the OpenSCAD mailing list archive at Nabble.com.
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
This is how I lay them out for clarity, with tabs aligning the test, '?' &':'
function x(p) =
(test)
? true_expression
: false_expression;
function many(p) =
(test1)
? (test1-t)
? t_expr
: f_expr
: (test1-f)
? t_expr
: f_expr; // etc
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