From 41675a2daf2f42d50ba5d0c7628bf42eacf5ae92 Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Mon, 6 Sep 2021 18:33:20 +0200
Subject: [PATCH] Generate procs for constants

---
 .../private/preserves_schema_nim.nim          | 37 ++++++++++++-------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/preserves/private/preserves_schema_nim.nim b/src/preserves/private/preserves_schema_nim.nim
index b57106f..886ddf3 100644
--- a/src/preserves/private/preserves_schema_nim.nim
+++ b/src/preserves/private/preserves_schema_nim.nim
@@ -240,21 +240,35 @@ proc nimTypeOf(scm: Schema; known: var TypeTable; sn: SchemaNode; name = ""): PN
     result = nkCommentStmt.newNode
     result.comment.add("Missing type generator for " & $sn.kind & " " & $sn)
 
-proc toConst(name: string; def: SchemaNode): Pnode =
+proc exportIdent(id: string): PNode = nn(nkPostFix, ident"*", ident(id))
+
+proc generateConstProcs(result: var seq[PNode]; name: string; def: SchemaNode) =
   case def.kind
   of snkLiteral:
-    result = nkConstDef.newNode.add(
-      name.ident.accQuote, newEmpty())
+    var stmts = nn(nkStmtList)
     case def.value.kind
     of pkSignedInteger:
-      discard result.add newIntNode(nkIntLit, def.value.int)
+      discard stmts.add newIntNode(nkIntLit, def.value.int)
     of pkSymbol:
-      discard result.add nn(nkCall,
+      discard stmts.add nn(nkCall,
         ident"symbol",
-        PNode(kind: nkStrLit, strVal: def.value.symbol),
-        ident"EmbeddedType")
+        PNode(kind: nkStrLit,
+          strVal: def.value.symbol),
+          ident"EmbeddedType")
     else:
-      raiseAssert("cannot convert " & $def & " to a Nim literal")
+      raiseAssert("conversion of " & $def & " to a Nim literal is not implemented")
+    var procId = name
+    procId[0] = procId[0].toLowerAscii
+    let constProc= nn(nkProcDef,
+      exportIdent(procId),
+      newEmpty(),
+      newEmpty(),
+      nn(nkFormalParams, ident"Preserve"),
+      newEmpty(),
+      newEmpty(),
+      stmts)
+    constProc.comment = $def
+    result.add constProc
   else: discard
 
 proc toNimLit(sn: SchemaNode): PNode =
@@ -336,7 +350,6 @@ proc preserveTypeOf(scm: Schema; known: var TypeTable; sn: SchemaNode; name = ""
     result = nimTypeOf(scm, known, sn, name)
 
 proc generateProcs(result: var seq[PNode]; name: string; sn: SchemaNode) =
-  proc exportIdent(id: string): PNode = nn(nkPostFix, ident"*", ident(id))
   case sn.kind
   of snkRecord:
     var
@@ -409,7 +422,6 @@ proc generateNimFile*(scm: Schema; path: string) =
   var
     knownTypes: TypeTable
     typeSection = newNode nkTypeSection
-    constSection = newNode nkLetSection
     procs: seq[PNode]
   if scm.embeddedType == "":
     typeSection.add nn(nkTypeDef,
@@ -429,7 +441,7 @@ proc generateNimFile*(scm: Schema; path: string) =
         ident"EmbeddedType"))
   for name, def in scm.definitions.pairs:
     if isConst(scm, def):
-      constSection.add toConst(name, def)
+      generateConstProcs(procs, name, def)
     else:
       var name = name
       name[0] = name[0].toUpperAscii
@@ -481,8 +493,7 @@ proc generateNimFile*(scm: Schema; path: string) =
   collectRefImports(imports, scm)
   var module = newNode(nkStmtList).add(
       imports,
-      typeSection,
-      constSection
+      typeSection
     ).add(procs)
   writeFile(path, renderTree(module, {renderNone, renderIr}))