Commit: 476522045be45336529417d240954a5b0e91ff66 - regiux (git)

A fast implementation of the Nix expression language

Commit MetaInfo

• Revisão: 476522045be45336529417d240954a5b0e91ff66 (tree)
• Hora: 2024-06-14 11:29:28
• Autor: Corbin <cds@corb...>
• Commiter: Corbin

Mensagem de Log

parser: Make string QLs left-recursive.

And, with this, there's no longer any good explanation for why we cannot
match formals and binds at the same top-level.

Mudança Sumário

• modified: parser.py

Diff

--- a/parser.py
+++ b/parser.py
@@ -180,16 +180,17 @@ class AppBox(EBox):
         compiler.mkApp()
 
 class StrQLBox(EBox):
-    def __init__(self, init, pairs):
-        self.init = init
+    def __init__(self, pairs, tail):
         self.pairs = pairs
+        self.tail = tail
     def pretty(self):
-        rv = [self.init]
-        for expr, piece in self.pairs:
+        rv = []
+        for piece, expr in self.pairs:
+            rv.append(piece)
             rv.append("${ ")
             rv.append(expr.pretty())
             rv.append(" }")
-            rv.append(piece)
+        rv.append(self.tail)
         return '"%s"' % "".join(rv)
     # def compile(self, compiler):
     #     l = [heap.HeapStr(self.init)]
@@ -439,23 +440,22 @@ def exprSimpleInt(p): return IntBox(int(p[0].getstr()))
 @pg.production("expr_simple : STRING")
 def exprQuoted(p): return StrBox(trimBox(p[0], 1, -1))
 
[e-mail]("expr_simple : STRING_INIT string_ql")
-def stringQL(p):
-    s = trimBox(p[0], 1, -2)
-    incomplete = p[1]
-    assert isinstance(incomplete, IncompleteQL)
-    return StrQLBox(s, incomplete.pairs)
[e-mail]("string_ql : STRING_INIT expr")
+def stringQL(p): return IncompleteQL([(trimBox(p[0], 1, -2), p[1])])
 
-# XXX should be left-recursive? Requires refactoring all string_ql rules
[e-mail]("string_ql : expr STRING_PIECE string_ql")
[e-mail]("string_ql : string_ql STRING_PIECE expr")
 def stringQLPiece(p):
-    incomplete = p[2]
+    incomplete = p[0]
     assert isinstance(incomplete, IncompleteQL)
-    pairs = [(p[0], trimBox(p[1], 1, -2))] + incomplete.pairs
+    pairs = incomplete.pairs + [(trimBox(p[1], 1, -2), p[2])]
     return IncompleteQL(pairs)
 
[e-mail]("string_ql : expr STRING_END")
-def stringQLEnd(p): return IncompleteQL([(p[0], trimBox(p[1], 1, -1))])
[e-mail]("expr_simple : string_ql STRING_END")
+def stringQLEnd(p):
+    incomplete = p[0]
+    assert isinstance(incomplete, IncompleteQL)
+    s = trimBox(p[1], 1, -1)
+    return StrQLBox(incomplete.pairs, s)
 
 @pg.production("expr_simple : URI")
 def exprURI(p): return StrBox(p[0].getstr())