1 files changed, 183 insertions, 0 deletions
diff --git a/gerberex/am_expression.py b/gerberex/am_expression.py
new file mode 100644
index 0000000..7aa95c8
--- /dev/null
+++ b/gerberex/am_expression.py
@@ -0,0 +1,183 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
+
+from gerber.utils import *
+from gerber.am_eval import OpCode
+from gerber.am_statements import *
+
+class AMExpression(object):
+    CONSTANT = 1
+    VARIABLE = 2
+    OPERATOR = 3
+
+    def __init__(self, kind):
+        self.kind = kind
+
+    @property
+    def value(self):
+        return self
+
+    def optimize(self):
+        pass
+    
+    def to_inch(self):
+        return AMOperatorExpression(AMOperatorExpression.DIV, self, 
+                                    AMConstantExpression(MILLIMETERS_PER_INCH))
+
+    def to_metric(self):
+        return AMOperatorExpression(AMOperatorExpression.MUL, self,
+                                    AMConstantExpression(MILLIMETERS_PER_INCH))
+
+    def to_gerber(self, settings=None):
+        pass
+
+    def to_instructions(self):
+        pass
+    
+class AMConstantExpression(AMExpression):
+    def __init__(self, value):
+        super(AMConstantExpression, self).__init__(AMExpression.CONSTANT)
+        self._value = value
+
+    @property
+    def value(self):
+        return self._value
+
+    def optimize(self):
+        return self
+    
+    def to_gerber(self, settings=None):
+        return str(self._value)
+
+    def to_instructions(self):
+        return [(OpCode.PUSH, self._value)]
+    
+class AMVariableExpression(AMExpression):
+    def __init__(self, number):
+        super(AMVariableExpression, self).__init__(AMExpression.VARIABLE)
+        self.number = number
+
+    def optimize(self):
+        return self
+    
+    def to_gerber(self, settings=None):
+        return '$%d' % self.number
+    
+    def to_instructions(self):
+        return (OpCode.LOAD, self.number)
+
+class AMOperatorExpression(AMExpression):
+    ADD = '+'
+    SUB = '-'
+    MUL = 'X'
+    DIV = '/'
+
+    def __init__(self, op, lvalue, rvalue):
+        super(AMOperatorExpression, self).__init__(AMExpression.OPERATOR)
+        self.op = op
+        self.lvalue = lvalue
+        self.rvalue = rvalue
+    
+    def optimize(self):
+        self.lvalue = self.lvalue.optimize()
+        self.rvalue = self.rvalue.optimize()
+
+        if isinstance(self.lvalue, AMConstantExpression) and isinstance(self.rvalue, AMConstantExpression):
+            lvalue = float(self.lvalue.value)
+            rvalue = float(self.rvalue.value)
+            value = lvalue + rvalue if self.op == self.ADD else \
+                lvalue - rvalue if self.op == self.SUB else \
+                lvalue * rvalue if self.op == self.MUL else \
+                lvalue / rvalue if self.op == self.DIV else None
+            return AMConstantExpression(value)
+        elif self.op == self.ADD:
+            if self.rvalue.value == 0:
+                return self.lvalue
+            elif self.lvalue.value == 0:
+                return self.rvalue
+        elif self.op == self.SUB:
+            if self.rvalue.value == 0:
+                return self.lvalue
+            elif self.lvalue.value == 0 and isinstance(self.rvalue, AMConstantExpression):
+                return AMConstantExpression(-self.rvalue.value)
+        elif self.op == self.MUL:
+            if self.rvalue.value == 1:
+                return self.lvalue
+            elif self.lvalue.value == 1:
+                return self.rvalue
+            elif self.lvalue == 0 or self.rvalue == 0:
+                return AMConstantExpression(0)
+        elif self.op == self.DIV:
+            if self.rvalue.value == 1:
+                return self.lvalue
+            elif self.lvalue.value == 0:
+                return AMConstantExpression(0)
+        
+        return self
+        
+    def to_gerber(self, settings=None):
+        return '(%s)%s(%s)' % (self.lvalue.to_gerber(settings), self.op, self.rvalue.to_gerber(settings))
+
+    def to_instructions(self):
+        for i in self.lvalue.to_instructions():
+            yield i
+        for i in self.rvalue.to_instructions():
+            yield i
+        op = OpCode.ADD if self.op == self.ADD else\
+             OpCode.SUB if self.op == self.SUB else\
+             OpCode.MUL if self.op == self.MUL else\
+             OpCode.DIV
+        yield (op, None)
+
+def eval_macro(instructions):
+    stack = []
+
+    def pop():
+        return stack.pop()
+
+    def push(op):
+        stack.append(op)
+
+    def top():
+        return stack[-1]
+
+    def empty():
+        return len(stack) == 0
+
+    for opcode, argument in instructions:
+        if opcode == OpCode.PUSH:
+            push(AMConstantExpression(argument))
+
+        elif opcode == OpCode.LOAD:
+            push(AMVariableExpression(argument))
+
+        elif opcode == OpCode.STORE:
+            yield (-argument, [pop()])
+
+        elif opcode == OpCode.ADD:
+            op1 = pop()
+            op2 = pop()
+            push(AMOperatorExpression(AMOperatorExpression.ADD, op2, op1))
+
+        elif opcode == OpCode.SUB:
+            op1 = pop()
+            op2 = pop()
+            push(AMOperatorExpression(AMOperatorExpression.SUB, op2, op1))
+
+        elif opcode == OpCode.MUL:
+            op1 = pop()
+            op2 = pop()
+            push(AMOperatorExpression(AMOperatorExpression.MUL, op2, op1))
+
+        elif opcode == OpCode.DIV:
+            op1 = pop()
+            op2 = pop()
+            push(AMOperatorExpression(AMOperatorExpression.DIV, op2, op1))
+
+        elif opcode == OpCode.PRIM:
+            yield (argument, stack)
+            stack = []
+
+