Mel

Basic

• Single line comment with //.
• Multi line comment /**/
• End every statement with a ;.

Commands

• Commands are like command-line utilities in a UNIX shell.
• Run a command with command [-flag value]. Each command has it's own number of flags (or commandline parameters).
• To get help about a command use the help command. Ex help sphere will print information on the command sphere.
• The same command is often able to both create, edit and query information.
  • The default is create mode. Ex sphere DaSphere
  • Use flag -query to get values. ex sphere -query -radius DaSphere
  • Use flag -edit to edit values. ex sphere -edit -radius 3 DaSphere
• To get the return value of a command enclose it in backquotes. Ex $pos = `sphere -q -s DaSphere`

Variables

• Define a variable with a $ and a name. ex float $earthsize = 100
• Supported types are int, float, string, vector and matrix
• If no value is assigned it get the default one for the type.
• A bool is stored in a int. 0 is false (no and off) , other values true (yes or on).
• Logical operators is: || (or), && (and), ! (not).
• Compare operators is: <, <=, >, >=, == and !=.

Text

• Merge strings with the + symbol.
• Get the length of a string with size. ex size($saymyname).
• Escape special characters with \.

Vector

• A vector is variable that contain three floating point numbers called x,y and z.
• Assign a vector with values in <<>>. ex vector $p = <<10,20,30>>
• Access each element as x,y,z inside a (). ex move -absolute ($p.x) ($p.y) ($p.z)
• To assign a vector element create a new one and assign. ex $p = <<($p.x), ($p.y), 40>>
• * operator acts as dot product for vectors.
• ^ operator is cross product operator for vectors. Use pow command for exponent of numbers.

Matrix

• A matrix is a table of floating point numbers.
• To create a matrix use the matrix type follow by the number of rows and columns. Ex matrix $m[3][4];
• Assign a matrix by using <<>> separated by commas in each row. matrix $m[2][2] = <<1,2;3,4>>
• Assign a element in the matrix with $m[1][2] = 5;

Statements

if ($a == $b) {

...

}

else if(($a == $c) {

...

}

else {

...

}

switch ($form) {

case "circle":

...

break;

case "cone":

...

break;

default:

...

break

}

while ($a < size($array)) {

...

}

do {

} while($a < 100)

for($i = 0; $i < 10; $i++) {

if ($i == 5) continue;

    ...

}

string $array[3] = {"circle","sphere", "cone"};

for ($k in $array) {

...

}

Reference

Mel Command Reference - 2017