add dump AST, make AST printing cleaner

src/nds.nim

@@ -26,6 +26,8 @@ proc interpret(name: string, source: string): Result =
     let node = parser.parse()
     if parser.hadError:
       return rsCompileError
+    when debugDumpAst:
+      echo $node
     let emitter = newEmitter(name, node)
     emitter.emit()
     if emitter.hadError:

src/ndspkg/compv2/node.nim

@@ -3,6 +3,7 @@ import ../types/value
 
 import strformat
 import strutils
+import sequtils
 
 type
   NodeKind* = enum
@@ -76,22 +77,16 @@ proc `$`*(node: Node): string =
     result = &"(and {node.left} {node.right})"
   of nkBlockExpr:
     let labels = node.labels.join(", ")
-    result = &"(block labels: {labels} elements: "
-    for ch in node.children:
-      result &= $ch & ", "
-    result[^1] = ')'
+    let elements = node.children.map(`$`).join(", ")
+    result = &"(block labels: {labels} elements: {elements})"
   of nkBreak:
     result = &"(break {node.label})"
   of nkCall:
-    result = &"(call {node.function} "
-    for ch in node.arguments:
-      result &= $ch & ", "
-    result[^1] = ')'
+    let args = node.arguments.map(`$`).join(", ")
+    result = &"(call {node.function}({args}))"
   of nkColonCall:
-    result = &"(:call {node.function} "
-    for ch in node.arguments:
-      result &= $ch & ", "
-    result[^1] = ')'
+    let args = node.arguments.map(`$`).join(", ")
+    result = &"(:call {node.function} ({args}))"
   of nkConst:
     result = &"(const {node.constant})"
   of nkDiv:
@@ -119,10 +114,8 @@ proc `$`*(node: Node): string =
   of nkLess:
     result = &"(less {node.left} {node.right})"
   of nkList:
-    result = &"(list "
-    for ch in node.elems:
-      result &= &"{ch}, "
-    result[^1] = ')'
+    let elems = node.elems.map(`$`).join(", ")
+    result = &"(list {elems})"
   of nkMinus:
     result = &"(- {node.left} {node.right})"
   of nkMult:
@@ -145,11 +138,8 @@ proc `$`*(node: Node): string =
   of nkSetIndex:
     result = &"({node.sCollection}[{node.sIndex}] = {node.sValue})"
   of nkTable:
-    var keys = ""
-    var values = ""
-    for i in 0..node.keys.high:
-      keys &= &"{node.keys[i]}, "
-      values &= &"{node.values[i]}, "
+    let keys = node.keys.map(`$`).join(", ")
+    let values = node.values.map(`$`).join(", ")
     result = &"(table keys: {keys}, values: {values})"
   of nkTrue:
     result = "(true)"

src/ndspkg/config.nim

@@ -3,7 +3,8 @@ type
     leBasic, leRdstdin
   ReadlineInterruptedException* = object of CatchableError
 
-const debugDumpChunk* = defined(debug)
+const debugDumpAst* = defined(debug) # dump AST after parsing
+const debugDumpChunk* = defined(debug) # dump emitted chunk
 # vm debug options (setting any to true will slow runtime down!)
 const debugVM* = defined(debug)
 const assertionsVM* = defined(debug) or defined(release) # sanity checks in the VM, such as the stack being empty at the end