Expressions

src/gboml/ast/__init__.py

@@ -6,7 +6,8 @@ __all__ = [
     "StdConstraint", "SOSConstraint", "Objective", "VariableDefinition", "Node",
     "HyperEdge", "NodeDefinition", "NodeImport", "HyperEdgeDefinition", "HyperEdgeImport",
     "ExpressionOp", "GBOMLGraph", "ImplicitLoop", "RValue", "RValueWithGen", "GeneratedRValue",
-    "Range", "MultiLoop", "DictEntry", "Dictionary", "NodeGenerator", "HyperEdgeGenerator"
+    "Range", "MultiLoop", "DictEntry", "Dictionary", "NodeGenerator", "HyperEdgeGenerator",
+    "DefinitionType"
 ]
 
 from gboml.ast.arrays import *

src/gboml/ast/variables.py

@@ -18,9 +18,14 @@ class VarType(Enum):
     binary = "binary"
 
 
+class DefinitionType(Enum):
+    constant = "="
+    expression = "<-"
+
 @dataclass
 class Definition(GBOMLObject):
     name: str
+    type: DefinitionType
     value: RValue
     tags: list[str] = field(default_factory=list)
 

src/gboml/gboml.lark

@@ -91,7 +91,8 @@ bool_expression_comparison: expression (COMPARISON_OPERATOR | CTR_OPERATOR) expr
 COMPARISON_OPERATOR:  "<" | ">" | "!="
 
 // DEFINITIONS
-definition: ID "=" rvalue tags ";"
+definition: ID DEF_TYPE rvalue tags ";"
+DEF_TYPE: "=" | "<-"
 
 // ARRAYS
 array_or_dict: "{" separated_maybe_empty_list{_array_or_dict_entry, ","} "}"

src/gboml/parsing.py

@@ -114,6 +114,7 @@ def _lark_to_gboml(tree: Tree, filename: Optional[str] = None) -> GBOMLGraph:
         def COMPARISON_OPERATOR(self, token): return Operator(token.value)
         def STRING(self, token): return token.value[1:-1].replace('\\"', '"')
         def VTYPE(self, token): return VarType(token.value)
+        def DEF_TYPE(self, token): return DefinitionType(token.value)
 
         NodesAndHyperEdges = namedtuple("NodesAndHyperEdges", ["nodes", "hyperedges"])
 

tests/instances/ok/complex_parsing.txt

@@ -5,7 +5,7 @@
     b = 2.2;
     c = 2e2;
     d = -1;
-    e = 2e-2;
+    e <- 2e-2;
     f = [0:2];
     g = [0:10:2];
 #NODE nodeI  = import nodeA from "hello.gboml";