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CodeGeneration

 Java
 translate Maple code to Java code

 Calling Sequence Java(x, cgopts)

Parameters

 x - expression, list, rtable, procedure, or module cgopts - (optional) one or more CodeGeneration options

Description

 • The Java(x, cgopts) calling sequence translates Maple code to Java code.
 - If the parameter x is an algebraic expression, then a Java statement assigning the expression to a variable is generated.
 - If x is a list, Maple Array, or rtable of algebraic expressions, then a sequence of Java statements assigning the elements to a Java array is produced.  Only the initialized elements of the rtable or Maple Array are translated.
 - If x is a list of equations $\mathrm{nm}=\mathrm{expr}$ where $\mathrm{nm}$ is a name and $\mathrm{expr}$ is an algebraic expression, this is understood as a sequence of assignment statements.  In this case, the equivalent sequence of Java assignment statements is generated.
 - If x is a procedure, then a Java class is generated containing a function equivalent to the procedure, along with any necessary import statements.
 - If x is a module, then a Java class is generated, as described on the JavaDetails help page.
 • The parameter cgopts may include one or more CodeGeneration options, as described in CodeGenerationOptions.

Examples

For a description of the options used in the following examples, see CodeGenerationOptions.

 > $\mathrm{with}\left(\mathrm{CodeGeneration}\right):$

Translate a simple expression and assign to the name $w$ in the target code.

 > $\mathrm{Java}\left(x+yz-2xz,\mathrm{resultname}="w"\right)$
 w = -2 * x * z + y * z + x;

Translate a list and assign to an array with name $w$ in the target code.

 > $\mathrm{Java}\left(\left[\left[x,2y\right],\left[5,z\right]\right],\mathrm{resultname}="w"\right)$
 w[0][0] = x; w[0][1] = 2 * y; w[1][0] = 5; w[1][1] = z;

Translate a computation sequence.  Optimize the input first.

 > $\mathrm{cs}≔\left[s=1.0+x,t=\mathrm{ln}\left(s\right){ⅇ}^{-x},r={ⅇ}^{-x}+xt\right]:$
 > $\mathrm{Java}\left(\mathrm{cs},\mathrm{optimize}\right)$
 s = 0.10e1 + x; t1 = Math.log(s); t2 = Math.exp(-x); t = t1 * t2; r = x * t + t2;

Declare that $x$ is a float and $y$ is an integer. Return the result in a string.

 > $s≔\mathrm{Java}\left(x+y+1,\mathrm{declare}=\left[x::\mathrm{float},y::\mathrm{integer}\right],\mathrm{output}=\mathrm{string}\right)$
 ${s}{:=}{"cg = x + \left(double\right) y + 0.1e1;"}$ (1)

Translate a procedure.  Assume that all untyped variables have type integer.

 > f := proc(x, y, z) return x*y-y*z+x*z; end proc:
 > $\mathrm{Java}\left(f,\mathrm{defaulttype}=\mathrm{integer}\right)$
 class CodeGenerationClass {   public static int f (int x, int y, int z)   {     return(x * y - y * z + x * z);   } }

Translate a procedure containing an implicit return.  A new variable is created to hold the return value.

 > f := proc(n)   local x, i;   x := 0.0;   for i to n do     x := x + i;   end do; end proc:
 > $\mathrm{Java}\left(f\right)$
 class CodeGenerationClass {   public static double f (int n)   {     double x;     int i;     double cgret;     x = 0.0e0;     for (i = 1; i <= n; i++)     {       x = x + (double) i;       cgret = x;     }     return(cgret);   } }

Translate a procedure accepting an Array as a parameter.  Note that the indices are renumbered so that the Java array starts at index 0.

 > f := proc(x::Array(numeric, 5..7))   return x[5]+x[6]+x[7]; end proc:
 > $\mathrm{Java}\left(f\right)$
 class CodeGenerationClass {   public static double f (double[] x)   {     return(x[0] + x[1] + x[2]);   } }

Translate a module.

 > m := module() export p; local q;     p := proc(x,y) if y>0 then trunc(x); else ceil(x); end if; end proc:     q := proc(x) sin(x)^2; end proc: end module:
 > $\mathrm{Java}\left(m,\mathrm{resultname}=\mathrm{t0}\right)$
 import java.lang.Math; class m {   public static int p (double x, int y)   {     if (0 < y)       return((int)(x));     else       return((int)Math.ceil(x));   }   private static double q (double x)   {     return(Math.pow(Math.sin(x), 0.2e1));   } }

Translate a linear combination of hyperbolic trigonometric functions.

 > $\mathrm{Java}\left(2\mathrm{cosh}\left(x\right)-7\mathrm{tanh}\left(x\right)\right)$
 cg0 = 0.2e1 * (Math.exp(x) + Math.exp((-0.1e1) * x)) / 0.2e1 - 0.7e1 * (Math.exp(0.2e1 * x) - 0.1e1) / (Math.exp(0.2e1 * x) + 0.1e1);

Translate a procedure with no return value containing a printf statement.

 > f := proc(a::integer, p::integer)   printf("The integer remainder of %d divided by %d is: %d\n", a, p, irem(a, p)); end proc:
 > $\mathrm{Java}\left(f\right)$
 class CodeGenerationClass {   public static void f (int a, int p)   {     System.out.println("The integer remainder of " + a + " divided by " + p + " is: " + a % p);   } }