🐐 String interpolation

centvrion/ast_nodes.py

@@ -275,6 +275,7 @@ class DataRangeArray(Node):
 class String(Node):
   def __init__(self, value) -> None:
     self.value = value
+    self.quote = '"'
 
   def __eq__(self, other):
     return type(self) == type(other) and self.value == other.value
@@ -283,12 +284,60 @@ class String(Node):
     return f"String({self.value})"
 
   def print(self):
-    return f'"{self.value}"'
+    if self.quote == "'":
+      return f"'{self.value}'"
+    escaped = self.value.replace('{', '{{').replace('}', '}}')
+    return f'"{escaped}"'
 
   def _eval(self, vtable):
     return vtable, ValStr(self.value)
 
 
+def _flip_quotes(node, quote):
+  """Recursively set quote style on all String nodes in an expression tree."""
+  if isinstance(node, String):
+    node.quote = quote
+  for attr in vars(node).values():
+    if isinstance(attr, Node):
+      _flip_quotes(attr, quote)
+    elif isinstance(attr, list):
+      for item in attr:
+        if isinstance(item, Node):
+          _flip_quotes(item, quote)
+
+
+class InterpolatedString(Node):
+  def __init__(self, parts) -> None:
+    self.parts = parts
+
+  def __eq__(self, other):
+    return type(self) == type(other) and self.parts == other.parts
+
+  def __repr__(self):
+    return f"InterpolatedString([{rep_join(self.parts)}])"
+
+  def print(self):
+    result = '"'
+    for part in self.parts:
+      if isinstance(part, String):
+        result += part.value.replace('{', '{{').replace('}', '}}')
+      else:
+        _flip_quotes(part, "'")
+        result += '{' + part.print() + '}'
+        _flip_quotes(part, '"')
+    result += '"'
+    return result
+
+  def _eval(self, vtable):
+    magnvm = "MAGNVM" in vtable["#modules"]
+    svbnvlla = "SVBNVLLA" in vtable["#modules"]
+    pieces = []
+    for part in self.parts:
+      vtable, val = part.eval(vtable)
+      pieces.append(make_string(val, magnvm, svbnvlla))
+    return vtable, ValStr(''.join(pieces))
+
+
 class Numeral(Node):
   def __init__(self, value: str) -> None:
     self.value = value