polynomial_interpreter.rb in congruence_solver-0.3.2

- old
+ new
@@ -1,116 +1,113 @@
-class PolynomialInterpreter
-  module Errors
-    POLYNOMIAL_INVALID = ArgumentError.new "polynomial invalid"
-    CONGRUENCE_INVALID = ArgumentError.new "congruence invalid"
-    LHS_POLYNOMIAL_INVALID = ArgumentError.new "lhs polynomial invalid"
-    RHS_POLYNOMIAL_INVALID = ArgumentError.new "rhs polynomial invalid"
-    MOD_INVALID = ArgumentError.new "mod invalid"
-  end
-
-
-  def self.read_congruence(input_congruence)
-    match_data = input_congruence.match(/^(.*)=(.*) +(?:mod +(.*)|\(mod +(.*)\))$/)
-
-    if match_data.nil? 
-      raise Errors::CONGRUENCE_INVALID 
-    end
-
-    lhs = match_data[1]
-    rhs = match_data[2]
-    mod = match_data[3] || match_data[4]
-
-    begin
-      lh_coeffs = read_coeffs(lhs.gsub(" ", ""))
-    rescue ArgumentError => e
-      if(e == Errors::POLYNOMIAL_INVALID)
-        raise "#{lhs}:#{Errors::RHS_POLYNOMIAL_INVALID}"
-      else
-        raise e
-      end
-    end
-
-    begin
-      rh_coeffs = read_coeffs(rhs.gsub(" ", ""))
-    rescue ArgumentError => e
-      if e == Errors::POLYNOMIAL_INVALID
-        raise "#{rhs}:#{Errors::RHS_POLYNOMIAL_INVALID}"
-      else
-        raise e
-      end
-    end
-
-    if mod !~ /\d+/ or mod.to_i < 2
-      raise Errors::MOD_INVALID
-    end
-
-    0.upto rh_coeffs.length-1 do |idx|
-      unless rh_coeffs[idx].nil?
-        lh_coeffs[idx] ||= 0
-        lh_coeffs[idx] -= rh_coeffs[idx]
-      end
-    end
-
-    [lh_coeffs, mod.to_i]
-  end
-
-  def self.read_coeffs(input_polynomial)
-    if input_polynomial == ""
-      raise Errors::POLYNOMIAL_INVALID
-    end
-
-    last_var = nil
-    coeffs = Array.new
-
-    loop do
-      input_polynomial.slice!(/^(\d+)\*?/)
-      match_data_coe = Regexp.last_match
-
-      input_polynomial.slice!(/^([a-zA-Z])(?:\^(\d+))?/)
-      match_data_exp = Regexp.last_match
-
-      if match_data_coe.nil? and match_data_exp.nil? 
-        raise Errors::POLYNOMIAL_INVALID 
-      else 
-        if match_data_exp.nil?
-          coe = match_data_coe[1].to_i
-          exp = 0
-        else
-          unless last_var.nil? or last_var == match_data_exp[1]
-              raise Errors::POLYNOMIAL_INVALID
-          end
-
-          last_var = match_data_exp[1]
-
-          if match_data_coe.nil?
-            coe = 1
-          else
-            coe = match_data_coe[1].to_i
-          end
-            
-          if match_data_exp[2].nil?
-              exp = 1
-          else
-            exp = match_data_exp[2].to_i
-          end
-        end
-      end
-
-      coeffs[exp] ||= 0
-      coeffs[exp] += coe.to_i
-
-      break if input_polynomial.length == 0
-
-      op = input_polynomial.slice!(0)
-
-      unless op.match /[-+]/
-        raise Errors::POLYNOMIAL_INVALID
-      end
-    end
-
-    0.upto(coeffs.length-1) do |idx|
-      coeffs[idx] ||= 0
-    end
-
-    coeffs
-  end
-end
\ No newline at end of file
+class PolynomialInterpreter
+  module Errors
+    POLYNOMIAL_INVALID = ArgumentError.new "polynomial invalid"
+    CONGRUENCE_INVALID = ArgumentError.new "congruence invalid"
+    LHS_POLYNOMIAL_INVALID = ArgumentError.new "lhs polynomial invalid"
+    RHS_POLYNOMIAL_INVALID = ArgumentError.new "rhs polynomial invalid"
+    MOD_INVALID = ArgumentError.new "mod invalid"
+  end
+
+
+  def self.read_congruence(input_congruence)
+    match_data = input_congruence.match(/^(.*)=(.*) +(?:mod +(.*)|\(mod +(.*)\))$/)
+
+    if match_data.nil?
+      raise Errors::CONGRUENCE_INVALID
+    end
+
+    lhs = match_data[1]
+    rhs = match_data[2]
+    mod = match_data[3] || match_data[4]
+
+    begin
+      lh_coeffs = read_coeffs(lhs.gsub(" ", ""))
+    rescue ArgumentError
+        raise Errors::LHS_POLYNOMIAL_INVALID
+    end
+
+    begin
+      rh_coeffs = read_coeffs(rhs.gsub(" ", ""))
+    rescue ArgumentError
+        raise Errors::RHS_POLYNOMIAL_INVALID
+    end
+
+    if mod !~ /\d+/ or mod.to_i < 2
+      raise Errors::MOD_INVALID
+    end
+
+    0.upto rh_coeffs.length-1 do |idx|
+      unless rh_coeffs[idx].nil?
+        lh_coeffs[idx] ||= 0
+        lh_coeffs[idx] -= rh_coeffs[idx]
+      end
+    end
+
+    [lh_coeffs, mod.to_i]
+  end
+
+  def self.read_coeffs(input_polynomial)
+    if input_polynomial == ""
+      raise Errors::POLYNOMIAL_INVALID
+    end
+
+    last_var = nil
+    coeffs = Array.new
+
+    unless input_polynomial[0].match /[-+]/
+      input_polynomial = "+" + input_polynomial
+    end
+
+    while input_polynomial.length > 0 do
+      op = input_polynomial.slice!(0)
+      unless op =~ /[-+]/
+        raise Errors::POLYNOMIAL_INVALID
+      end
+
+      input_polynomial.slice!(/^(\d+)\*?/)
+      match_data_coe = Regexp.last_match
+
+      input_polynomial.slice!(/^([a-zA-Z])(?:\^(\d+))?/)
+      match_data_exp = Regexp.last_match
+
+      if match_data_coe.nil? and match_data_exp.nil?
+        raise Errors::POLYNOMIAL_INVALID
+      else
+        if match_data_exp.nil?
+          coe = match_data_coe[1].to_i
+          exp = 0
+        else
+          unless last_var.nil? or last_var == match_data_exp[1]
+              raise Errors::POLYNOMIAL_INVALID
+          end
+
+          last_var = match_data_exp[1]
+
+          if match_data_coe.nil?
+            coe = 1
+          else
+            coe = match_data_coe[1].to_i
+          end
+
+          if match_data_exp[2].nil?
+              exp = 1
+          else
+            exp = match_data_exp[2].to_i
+          end
+        end
+      end
+
+      coeffs[exp] ||= 0
+      if op == "-"
+        coeffs[exp] -= coe.to_i
+      else
+        coeffs[exp] += coe.to_i
+      end
+    end
+
+    0.upto(coeffs.length-1) do |idx|
+      coeffs[idx] ||= 0
+    end
+
+    coeffs
+  end
+end