From f9f67c5a18bab8fb075f12f9d46a329429739bbe Mon Sep 17 00:00:00 2001
From: qu1ck <anlutsenko@gmail.com>
Date: Mon, 22 Oct 2018 23:57:17 -0700
Subject: [PATCH] Implement netlist parser

---
 InteractiveHtmlBom/schematic_data/__init__.py |  4 ++-
 .../schematic_data/netlistparser.py           | 36 +++++++++++++++++++
 .../schematic_data/sexpressions.py            | 32 +++++++++++++++++
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 InteractiveHtmlBom/schematic_data/netlistparser.py
 create mode 100644 InteractiveHtmlBom/schematic_data/sexpressions.py

diff --git a/InteractiveHtmlBom/schematic_data/__init__.py b/InteractiveHtmlBom/schematic_data/__init__.py
index 0e4e242d..5601da78 100644
--- a/InteractiveHtmlBom/schematic_data/__init__.py
+++ b/InteractiveHtmlBom/schematic_data/__init__.py
@@ -1,9 +1,11 @@
 import os
 
 from xmlparser import XmlParser
+from netlistparser import NetlistParser
 
 PARSERS = {
-    '.xml': XmlParser
+    '.xml': XmlParser,
+    '.net': NetlistParser
 }
 
 
diff --git a/InteractiveHtmlBom/schematic_data/netlistparser.py b/InteractiveHtmlBom/schematic_data/netlistparser.py
new file mode 100644
index 00000000..b36805a2
--- /dev/null
+++ b/InteractiveHtmlBom/schematic_data/netlistparser.py
@@ -0,0 +1,36 @@
+from parser_base import ParserBase
+from sexpressions import parse_sexpression
+
+
+class NetlistParser(ParserBase):
+    def get_extra_field_data(self):
+        with open(self.file_name, 'r') as f:
+            sexpression = parse_sexpression(f.read())
+        components = None
+        for s in sexpression:
+            if s[0] == 'components':
+                components = s[1:]
+        if components is None:
+            return None
+        field_set = set()
+        comp_dict = {}
+        for c in components:
+            ref = None
+            fields = None
+            for f in c[1:]:
+                if f[0] == 'ref':
+                    ref = f[1]
+                if f[0] == 'fields':
+                    fields = f[1:]
+            if ref is None:
+                return None
+            if fields is None:
+                continue
+            for f in fields:
+                if len(f) > 1:
+                    field_set.add(f[1][1])
+                if len(f) > 2:
+                    ref_fields = comp_dict.setdefault(ref, {})
+                    ref_fields[f[1][1]] = f[2]
+
+        return list(field_set), comp_dict
diff --git a/InteractiveHtmlBom/schematic_data/sexpressions.py b/InteractiveHtmlBom/schematic_data/sexpressions.py
new file mode 100644
index 00000000..54bef57d
--- /dev/null
+++ b/InteractiveHtmlBom/schematic_data/sexpressions.py
@@ -0,0 +1,32 @@
+import re
+
+term_regex = r'''(?mx)
+    \s*(?:
+        (?P<open>\()|
+        (?P<close>\))|
+        (?P<sq>"[^"]*")|
+        (?P<s>[^(^)\s]+)
+       )'''
+pattern = re.compile(term_regex)
+
+
+def parse_sexpression(sexpression):
+    stack = []
+    out = []
+    for terms in pattern.finditer(sexpression):
+        term, value = [(t, v) for t, v in terms.groupdict().items() if v][0]
+        if term == 'open':
+            stack.append(out)
+            out = []
+        elif term == 'close':
+            assert stack, "Trouble with nesting of brackets"
+            tmp, out = out, stack.pop(-1)
+            out.append(tmp)
+        elif term == 'sq':
+            out.append(value[1:-1])
+        elif term == 's':
+            out.append(value)
+        else:
+            raise NotImplementedError("Error: %s, %s" % (term, value))
+    assert not stack, "Trouble with nesting of brackets"
+    return out[0]