fix neg sign

spec/eeeval_spec.cr

@@ -258,4 +258,20 @@ describe EEEval::CalcFuncParser do
       val2.should eq(0.022222222222222223)
     end
   end
+
+  describe "#evaluate", tags: "acos" do
+    it "Calculate expression with acos" do
+      expression = "cos(2) + acos(-1)"
+      val1 = EEEval::CalcFuncParser.evaluate(expression).to_f
+      val1.should eq(2.7254458170426505)
+    end
+  end
+
+  describe "#evaluate", tags: "negative" do
+    it "Calculate expression with negative value" do
+      expression = "-0.4161468365471424+3.141592653589793"
+      val1 = EEEval::CalcFuncParser.evaluate(expression).to_f
+      val1.should eq(2.7254458170426505)
+    end
+  end
 end

src/eeeval.cr

@@ -13,7 +13,9 @@ module EEEval
   end
 
   class CalcParser
+
     def self.clear_expression(expression)
+      Log.trace {"clearing expression #{expression}"}
       expression = expression.delete(" ").gsub("+-", "-").gsub("-+", "-").gsub("--", "+").gsub("++", "+")
       expression = expression.gsub(/(?<=\()\-/, "0-").gsub(/(?<=\()\+/, "0+").gsub(/^\-/, "0-").gsub(/^\+/, "0+")
       raise Exception.new("malformed expression: check parentheeses") if(expression.count('(') != expression.count(')'))
@@ -53,7 +55,7 @@ module EEEval
     def self.evaluate_expr(expression)
       expression = convert_scinot(expression)
       expression = convert_multdiv_sign(expression)
-      expression = expression.gsub("+-", "-").gsub("-+", "-").gsub("--", "+").gsub("++", "+")
+      expression = clear_expression(expression)
       Log.trace { "evaluate_expr: #{expression}" }
       value = ""
       unless (expression.to_f?)
@@ -72,6 +74,7 @@ module EEEval
 
   class CalcFuncParser
     def self.evaluate(expression)
+      Log.trace {" INIT evaluation"}
       expression = CalcParser.clear_expression(expression)
       unless (expression.to_f?)
         MathFuncResolver.evaluate(expression)

src/eval/math_func_resolver.cr

@@ -90,7 +90,7 @@ module EEEval
         replaces = Hash(String, Float64).new
 
         {% for mfunc in funcs %}
-        expression.scan(/(?<={{mfunc.id}})\([\d+\s\)\(\*\-\+\/\^\.]*/) do |md|
+        expression.scan(/(?<=\b{{mfunc.id}}\b)\([\d+\s\)\(\*\-\+\/\^\.]*/) do |md|
           expr = search_expr(md[0])
           expr.try do |expr|
             key = "{{mfunc.id}}(#{expr})"