documented AST overloading and some TR optimizations

tests/patterns/thoist.nim

@@ -0,0 +1,13 @@
+discard """
+  output: '''true
+true'''
+"""
+
+import pegs
+
+template optPeg{peg(pattern)}(pattern: string{lit}): TPeg =
+  var gl {.global, gensym.} = peg(pattern)
+  gl
+
+echo match("(a b c)", peg"'(' @ ')'")
+echo match("W_HI_Le", peg"\y 'while'")

tests/patterns/tpartial.nim

@@ -0,0 +1,11 @@
+discard """
+  output: '''-1'''
+"""
+
+proc p(x, y: int; cond: bool): int =
+  result = if cond: x + y else: x - y
+
+template optP{p(x, y, true)}(x, y: expr): expr = x - y
+template optP{p(x, y, false)}(x, y: expr): expr = x + y
+
+echo p(2, 4, true)