Artifact Content
Not logged in

Artifact cc1b586b87325960250b91c2fa6e49d2c6ec86c4


     1  /**
     2   * Authors: k.inaba
     3   * License: NYSL 0.9982 http://www.kmonos.net/nysl/
     4   *
     5   * Common tricks and utilities for programming in D.
     6   */
     7  module tricks.tricks;
     8  import tricks.test;
     9  import core.exception;
    10  import std.array  : appender;
    11  import std.format : formattedWrite;
    12  import std.traits;
    13  import std.typetuple;
    14  
    15  /// Simple Wrapper for std.format.doFormat
    16  
    17  string sprintf(string fmt, T...)(T params)
    18  {
    19  	auto writer = appender!string();
    20  	formattedWrite(writer, fmt, params);
    21  	return writer.data;
    22  }
    23  
    24  unittest
    25  {
    26  	assert_eq( sprintf!"%s == %04d"("1+2", 3), "1+2 == 0003" );
    27  	assert_eq( sprintf!"%2$s == %1$s"("1+2", 5, 8), "5 == 1+2" );
    28  	assert_throw!Error( sprintf!"%s%s"(1) );
    29  }
    30  
    31  /// Create an exception with automatically completed filename and lineno information
    32  
    33  ExceptionType genex(ExceptionType, string fn=__FILE__, int ln=__LINE__, T...)(T params)
    34  {
    35  	static if( T.length > 0 && is(T[$-1] : Throwable) )
    36  		return new ExceptionType(params[0..$-1], fn, ln, params[$-1]);
    37  	else
    38  		return new ExceptionType(params, fn, ln);
    39  }
    40  
    41  unittest
    42  {
    43  	assert_ne( genex!Exception("msg").file, "" );
    44  	assert_ne( genex!Exception("msg").line, 0 );
    45  	assert_ne( genex!Exception("msg",new Exception("bar")).next, Exception.init );
    46  }
    47  
    48  /// Mixing-in the bean constructor for a class
    49  
    50  /*mixin*/
    51  template SimpleConstructor()
    52  {
    53  	/// member-by-member constructor
    54  	static if( is(typeof(super) == Object) || super.tupleof.length==0 )
    55  		this( typeof(this.tupleof) params )
    56  		{
    57  			static if(this.tupleof.length>0)
    58  				this.tupleof = params;
    59  		}
    60  	else
    61  		this( typeof(super.tupleof) ps, typeof(this.tupleof) params )
    62  		{
    63  			// including (only) the direct super class members
    64  			// may not always be a desirable choice, but should work for many cases
    65  			super(ps);
    66  			static if(this.tupleof.length>0)
    67  				this.tupleof = params;
    68  		}
    69  }
    70  
    71  unittest
    72  {
    73  	class Temp
    74  	{
    75  		int x;
    76  		string y;
    77  		mixin SimpleConstructor;
    78  	}
    79  	assert_eq( (new Temp(1,"foo")).x, 1 );
    80  	assert_eq( (new Temp(1,"foo")).y, "foo" );
    81  	assert( !__traits(compiles, new Temp) );
    82  	assert( !__traits(compiles, new Temp(1)) );
    83  	assert( !__traits(compiles, new Temp("foo",1)) );
    84  
    85  	class Tomp : Temp
    86  	{
    87  		real z;
    88  		mixin SimpleConstructor;
    89  	}
    90  	assert_eq( (new Tomp(1,"foo",2.5)).x, 1 );
    91  	assert_eq( (new Tomp(1,"foo",2.5)).y, "foo" );
    92  	assert_eq( (new Tomp(1,"foo",2.5)).z, 2.5 );
    93  	assert( !__traits(compiles, new Tomp(3.14)) );
    94  
    95  	// shiyo- desu. Don't use in this way.
    96  	//   Tamp tries to call new Tomp(real) (because it only sees Tomp's members),
    97  	//   but it fails because Tomp takes (int,string,real).
    98  	assert( !__traits(compiles, {
    99  		class Tamp : Tomp { mixin SimpleConstructor; }
   100  	}) );
   101  }
   102  
   103  /// Mixing-in the MOST-DERIVED-member-wise comparator for a class
   104  
   105  template SimpleToHash()
   106  {
   107  	override hash_t toHash() const /// member-by-member hash
   108  	{
   109  		hash_t h = 0;
   110  		foreach(mem; this.tupleof)
   111  			h += typeid(mem).getHash(&mem);
   112  		return h;
   113  	}
   114  }
   115  
   116  /// Mixing-in the MOST-DERIVED-member-wise comparator for a class
   117  
   118  /*mixin*/
   119  template SimpleCompare()
   120  {
   121  	override bool opEquals(Object rhs_) const /// member-by-member equality
   122  	{
   123  		if( auto rhs = cast(typeof(this))rhs_ )
   124  		{
   125  			foreach(i,_; this.tupleof)
   126  				if( this.tupleof[i] != (cast(const)rhs).tupleof[i] )
   127  					return false;
   128  			return true;
   129  		}
   130  		assert(false, sprintf!"Cannot compare %s with %s"(typeid(this), typeid(rhs_)));
   131  	}
   132  
   133  	mixin SimpleToHash;
   134  
   135  	override int opCmp(Object rhs_) const /// member-by-member compare
   136  	{
   137  		if( auto rhs = cast(typeof(this))rhs_ )
   138  		{
   139  			foreach(i,_; this.tupleof)
   140  				if( this.tupleof[i] != (cast(const)rhs).tupleof[i] ) {
   141  					auto a = (cast(SC_Unqual!(typeof(this)))this).tupleof[i];
   142  					auto b =  rhs.tupleof[i];
   143  					return a < b ? -1 : +1;
   144  				}
   145  // not work well for structures???????
   146  //				if(auto c = typeid(_).compare(&this.tupleof[i],&rhs.tupleof[i]))
   147  //					return c;
   148  			return 0;
   149  		}
   150  		assert(false, sprintf!"Cannot compare %s with %s"(typeid(this), typeid(rhs_)));
   151  	}
   152  }
   153  
   154  alias std.traits.Unqual SC_Unqual;
   155  
   156  unittest
   157  {
   158  	class Temp
   159  	{
   160  		int x;
   161  		string y;
   162  		mixin SimpleConstructor;
   163  		mixin SimpleCompare;
   164  	}
   165  	assert_eq( new Temp(1,"foo"), new Temp(1,"foo") );
   166  	assert_eq( (new Temp(1,"foo")).toHash, (new Temp(1,"foo")).toHash );
   167  	assert_ne( new Temp(1,"foo"), new Temp(2,"foo") );
   168  	assert_ne( new Temp(1,"foo"), new Temp(1,"bar") );
   169  	assert_gt( new Temp(1,"foo"), new Temp(1,"bar") );
   170  	assert_lt( new Temp(1,"foo"), new Temp(2,"bar") );
   171  	assert_ge( new Temp(1,"foo"), new Temp(1,"foo") );
   172  
   173  	class TempDummy
   174  	{
   175  		int x;
   176  		string y;
   177  		mixin SimpleConstructor;
   178  		mixin SimpleCompare;
   179  	}
   180  	assert_throw!AssertError( new Temp(1,"foo") == new TempDummy(1,"foo") );
   181  	assert_throw!AssertError( new Temp(1,"foo") <= new TempDummy(1,"foo") );
   182  }
   183  
   184  /// Mixing-in a simple toString method
   185  
   186  /*mixin*/
   187  template SimpleToString()
   188  {
   189  	/// member-by-member toString
   190  	override string toString()
   191  	{
   192  		string str = sprintf!"%s("(typeof(this).stringof);
   193  		foreach(i,mem; this.tupleof)
   194  		{
   195  			if(i) str ~= ",";
   196  			static if( is(typeof(mem) == std.bigint.BigInt) )
   197  				str ~= std.bigint.toDecimalString(mem);
   198  			else
   199  				str ~= sprintf!"%s"(mem);
   200  		}
   201  		return str ~ ")";
   202  	}
   203  }
   204  
   205  version(unittest) import std.bigint;
   206  unittest
   207  {
   208  	class Temp
   209  	{
   210  		int x;
   211  		string y;
   212  		BigInt z;
   213  		mixin SimpleConstructor;
   214  		mixin SimpleToString;
   215  	}
   216  	assert_eq( (new Temp(1,"foo",BigInt(42))).toString(), "Temp(1,foo,42)" );
   217  }
   218  
   219  /// Everything is in
   220  
   221  /*mixin*/
   222  template SimpleClass()
   223  {
   224  	mixin SimpleConstructor;
   225  	mixin SimpleCompare;
   226  	mixin SimpleToString;
   227  }
   228  
   229  /// Will be used for dynamic overload resolution pattern
   230  
   231  template firstParam(T)
   232  {
   233  	alias ParameterTypeTuple!(T)[0] firstParam;
   234  }