b1scad add support for $fn identifier and negative numbers

src/b1scad/scad/model14.scad

@@ -0,0 +1 @@
+sphere($fn = 16, r = 10);

src/b1scad/scad2ast.py

@@ -16,7 +16,7 @@ class OpenSCADLexer(Lexer):
         TRANSLATE, ROTATE, SCALE, UNION, DIFFERENCE, HULL,
         LBRACE, RBRACE, LPAREN, RPAREN, LSQUARE, RSQUARE, COMMA, SEMICOLON,
         NUMBER,
-        IDENTIFIER, EQU,
+        IDENTIFIER, SFN, EQU,
     )
     ignore = ' \t\n'
 
@@ -31,8 +31,9 @@ class OpenSCADLexer(Lexer):
     SCALE = r'scale'
     HULL = r'hull'
 
-    IDENTIFIER = r'[\$a-zA-Z_][a-zA-Z0-9_]*'
-    NUMBER = r'\d+(\.\d+)?'
+    IDENTIFIER = r'[a-zA-Z_][a-zA-Z0-9_]*'
+    SFN = r'\$fn'
+    NUMBER = r'[+-]?\d+(\.\d+)?'
 
     LBRACE = r'\{'
     RBRACE = r'\}'

src/b1scad/scad2py.py

@@ -94,13 +94,20 @@ def shape(self, p):
             # probably still needs fixing
             return f"self.api.cylinder_z({p.args})"
 
+    @_('SFN EQU NUMBER')
+    def args(self, p):
+        return ""
+
     @_('IDENTIFIER EQU NUMBER')
     def args(self, p):
-        id = p.IDENTIFIER.replace('$','_')
-        return f"{id} = {str(p.NUMBER)}"
+        return f"{p.IDENTIFIER} = {str(p.NUMBER)}"
 
     @_('args COMMA args')
     def args(self, p):
+        if p.args0 == "":
+            return f"{p.args1}"
+        if p.args1 == "":
+            return f"{p.args0}"
         return f"{p.args0}, {p.args1}"
 
     @_('NUMBER')

src/b1scad/test.py

@@ -27,7 +27,7 @@ class B1scadTestMethods(unittest.TestCase):
     """Pylele Test Class"""
     def test_all_scad(self):
         scaddir = os.path.join(os.path.abspath(os.path.dirname(__file__)),"scad")
-        for idx in range(14):
+        for idx in range(15):
             fname = f"model{idx:02}"
             scadfname = f"{fname}.scad"
             fullscadfile = os.path.join(scaddir,scadfname)