[add] Added the calculate module to calculate Expression.

sjscript/src/sjscript/Expression.d

@@ -1,19 +1,24 @@
 /// License: MIT
+///
+/// Types declared in this file are not considered at copying because of processing speed.
+/// So you should add a const qual when use them after parsing.
+///
 module sjscript.Expression;
 
-import std.variant;
+import std.algorithm,
+       std.meta,
+       std.variant;
 
 ///
 struct Expression {
  public:
   ///
-  Expression opBinary(string op : "+")(Term rhs) {
+  Expression opBinary(string op)(Term rhs) if (op == "+" || op == "-") {
+    static if (op == "-") {
+      rhs = rhs * -1f;
+    }
     return Expression(terms ~ rhs);
   }
-  ///
-  Expression opBinary(string op : "-")(Term rhs) {
-    return Expression(terms ~ rhs*(-1f));
-  }
 
   ///
   Term[] terms;
@@ -26,26 +31,19 @@ struct Term {
   alias Value = Algebraic!(float, string, FunctionCall, Expression);
 
   ///
-  Term opBinary(string op : "*", T)(T rhs) {
+  Term opBinary(string op, T)(T rhs) if ((op == "*" || op == "/")) {
     static if (is(T == Term)) {
-      return Term(
-          numerator   ~ rhs.numerator,
-          denominator ~ rhs.denominator);
+      auto rnumerator   = rhs.numerator;
+      auto rdenominator = rhs.denominator;
+    } else static if (staticIndexOf!(T, Value.AllowedTypes) >= 0) {
+      auto    rnumerator = [Value(rhs)];
+      Value[] rdenominator;
     } else {
-      return Term(
-          numerator ~ Value(rhs), denominator);
-    }
-  }
-  ///
-  Term opBinary(string op : "/", T)(T rhs) {
-    static if (is(T == Term)) {
-      return Term(
-          numerator   ~ rhs.denominator,
-          denominator ~ rhs.numerator);
-    } else {
-      return Term(
-          numerator, denominator ~ Value(rhs));
+      static assert(false);
     }
+    static if (op == "/") swap(rnumerator, rdenominator);
+
+    return Term(numerator ~ rnumerator, denominator ~ rdenominator);
   }
 
   ///
@@ -59,7 +57,6 @@ struct FunctionCall {
  public:
   ///
   string name;
-
   ///
   Expression[] args;
 }

sjscript/src/sjscript/ParametersBlock.d

@@ -24,10 +24,10 @@ struct ParametersBlock {
 struct Period {
  public:
   ///
-  size_t start;
+  float start;
 
   ///
-  size_t end;
+  float end;
 }
 
 ///

sjscript/src/sjscript/calculate.d

@@ -0,0 +1,65 @@
+/// License: MIT
+module sjscript.calculate;
+
+import std.algorithm,
+       std.exception,
+       std.format,
+       std.math,
+       std.traits,
+       std.variant;
+
+import sjscript.Expression;
+
+///
+enum IsVarStore(T) =
+  is(typeof((T vars, string name) => vars[name])) &&
+  is(ReturnType!((T vars, string name) => vars[name]) == float);
+static assert(IsVarStore!(float[string]));
+
+///
+struct NullVarStore {
+ public:
+  static float opIndex(string name) {
+    // TODO: error handling
+    throw new Exception("undefined variable %s".format(name));
+  }
+  static assert(IsVarStore!NullVarStore);
+}
+
+///
+float CalculateExpression(VarStore)(in Expression expr, VarStore vars)
+    if (IsVarStore!VarStore) {
+  return expr.terms.map!(x => x.CalculateTerm(vars)).sum;
+}
+
+///
+float CalculateTerm(VarStore)(in Term term, VarStore vars)
+    if (IsVarStore!VarStore) {
+  auto num = 1f, den = 1f;
+  term.numerator.
+    map!(x => x.CalculateTermValue(vars)).
+    each!(x => num *= x);
+  term.denominator.
+    map!(x => x.CalculateTermValue(vars)).
+    each!(x => den *= x);
+  (!den.approxEqual(0)).enforce();
+  return num / den;
+}
+
+///
+float CalculateTermValue(VarStore)(in Term.Value value, VarStore vars)
+    if (IsVarStore!VarStore) {
+  return value.visit!(
+      (string name)          => vars[name],
+      (float  val)           => val,
+      (in FunctionCall func) => func.CalculateFunction(vars),
+      (in Expression expr)   => expr.CalculateExpression(vars));
+}
+
+///
+float CalculateFunction(VarStore)(in FunctionCall fcall, VarStore vars)
+    if (IsVarStore!VarStore) {
+  const args = fcall.args.map!(x => x.CalculateExpression(vars));
+  // TODO: calling function
+  return 0;
+}

sjscript/src/sjscript/parse.d

@@ -8,7 +8,8 @@ import dast.parse;
 
 import sjscript.Expression,
        sjscript.ParametersBlock,
-       sjscript.Token;
+       sjscript.Token,
+       sjscript.calculate;
 
 ///
 unittest {
@@ -62,12 +63,13 @@ private class RuleSet {
 
   static Period ParsePeriod(
       @(TokenType.OpenBracket) Token,
-      @(TokenType.Number) Token begin,
+      Expression start,
       @(TokenType.DoubleDot) Token,
-      @(TokenType.Number) Token end,
+      Expression end,
       @(TokenType.CloseBracket) Token) {
     return Period(
-        begin.text.to!float.to!int, end.text.to!float.to!int);
+        start.CalculateExpression(NullVarStore()),
+        end  .CalculateExpression(NullVarStore()));
   }
 
   static Parameter[] ParseParameterListFirstItem(Parameter param) {

sjscript/test/test01.sj

@@ -16,7 +16,8 @@ $define shoot {
   translate_y += __dir_y;
 }
 
-A [0..10] {
+$define beat {0}
+A [$beat..$beat+10] {
   $define sinwave_add_x {0.5}
   $define sinwave_add_y {0.5}
   $define sinwave_amp_x {0.5}
@@ -24,11 +25,15 @@ A [0..10] {
   $define sinwave_hz    {2}
   $sinwave
 }
-B [10..20] {
+
+$define beat {10}
+B [$beat..$beat+10/2] {
   $define horming_speed {0.1}
   $horming
 }
-C [20..30] {
+
+$define beat {20}
+C [$beat..$beat+10/2] {
   $define shoot_speed {0.1}
   $shoot
 }