refactor: make rest of transforms non-stateful

BREAKING CHANGE: transform errors have different structure

src/generate.fnk

@@ -2,30 +2,35 @@ babel_traverse = import '@babel/traverse'
 {default: traverse} = babel_traverse
 
 {transformFromAstSync} = import '@babel/core'
-{is_empty} = import '@fink/std-lib/iter.fnk'
 
-{transform_ast} = import './lang/init.fnk'
+{transform} = import './lang/transform.fnk'
+{init_ctx} = import './lang/init.fnk'
 
 {transform_do_expr} = import './js/do-expression.fnk'
 {transform_async} = import './js/async.fnk'
 {module_transforms} = import './js/module.fnk'
 
 
 
-transform = fn node, code, filename, options:
-  ast = transform_ast node, code, filename, options
+transform_file = fn fink_ast, code, filename, options:
+  ctx = init_ctx code, filename
+
+  [error, [js_ast]=[]] = try:
+    transform fink_ast, {...ctx, options}
 
   extras = match options:
     {module_type: 'cjs'}: module_transforms
     else: {}
 
-  match ast:
-    {errors: is_empty ?}:
-      traverse ast, dict:
+  match error:
+    false:
+      traverse js_ast, dict:
         DoExpression: transform_do_expr
         AwaitExpression: {enter: transform_async}
         ...extras
-  ast
+      {...js_ast, errors: []}
+    else:
+      {errors: [error]}
 
 
 
@@ -51,17 +56,10 @@ babel_generate = fn ast, filename, source, options:
 
 
 generate = fn ast, filename, source, options={}:
-  js_ast = transform ast, source, filename, options
+  js_ast = transform_file ast, source, filename, options
 
   match js_ast:
     {errors: [{}]}:
       {code: '', source_map: '', errors: js_ast.errors}
     else:
       babel_generate js_ast, filename, source, options
-
-
-
-
-
-
-

src/generate.test.fnk

@@ -51,13 +51,13 @@ describe 'errors', fn:
         '
 
   it 'errors with code snippet', fn:
-    {errors: [{error}]} = fink2js '
+    {errors: [{message}]} = fink2js '
       foo = bar
       123 = foo
       shrub = ni'
 
     expect
-      error
+      message
       to_equal '
         test.fnk:2:0
         1| foo = bar
@@ -66,6 +66,8 @@ describe 'errors', fn:
         3| shrub = ni
 
         Unable to transform `assign =`.
+
+        TypeError: Property left of AssignmentExpression expected node to be of a type ["LVal"] but instead got "NumericLiteral"
         '
 
   it 'errors with bad babel options', fn:
@@ -79,7 +81,7 @@ describe 'errors', fn:
 
 
   it 'errors when provided with unknown tokens', fn:
-    {errors: [{error}]} = generate
+    {errors: [{message}]} = generate
       dict:
         type: 'test'
         op: 'foobar'
@@ -90,11 +92,13 @@ describe 'errors', fn:
       'test.fnk', 'foobar'
 
     expect
-      error
+      message
       to_equal '
         test.fnk:1:0
         1| foobar
            ^
 
         Unable to transform `test foobar`.
+
+        Unknown expression.
         '

src/js/identifier.fnk

@@ -15,9 +15,6 @@ check_ident = rx'
   [_$\p{L}][_$\p{L}\p{N}]*$'
 
 
-# TODO: move into ctx
-var_prefix = 'ˆ'
-
 str_36 = base_n ?, 36
 
 

src/lang/assignment/init.fnk

@@ -7,6 +7,7 @@ babel_types = import '@babel/types'
 } = babel_types
 {length, is_empty} = import '@fink/std-lib/iter.fnk'
 
+{unique_ident} = import '../../js/types.fnk'
 {transform_left: xform_left} = import '../../js/left.fnk'
 {wrap_with_comment_loc} = import '../comments/init.fnk'
 {add, any} = import '../context.fnk'
@@ -85,9 +86,9 @@ slice = fn items, start, end=false:
 
 transform_spread_right = fn expr, ctx:
   {left, right} = expr
-  items = ctx.unique_ident 'items'
+  [items, init_ctx] = unique_ident 'items', ctx
   # TODO: wrap declarator?
-  [init, next_ctx] = transform_value right, ctx
+  [init, next_ctx] = transform_value right, init_ctx
 
   items_init = wrap_with_comment_loc
     variableDeclaration
@@ -141,10 +142,10 @@ transform_await_left = fn node, ctx:
 
 transform_await_right = fn expr, ctx:
   {left, right} = expr
-  items = ctx.unique_ident 'items'
-  iter = ctx.unique_ident 'iter'
+  [items, iter_ctx] = unique_ident 'items', ctx
+  [iter, init_ctx] = unique_ident 'iter', iter_ctx
 
-  [init, next_ctx] = transform_value right, ctx
+  [init, next_ctx] = transform_value right, init_ctx
 
   items_init = wrap_with_comment_loc
     variableDeclaration 'const', [variableDeclarator items, init]

src/lang/block/init.fnk

@@ -7,7 +7,7 @@ babel_types = import '@babel/types'
 
 {add, any} = import '../context.fnk'
 {wrap_with_comment_loc} = import '../comments/init.fnk'
-{transform, collect_with_ctx} = import '../transform.fnk'
+{transform, map_with_ctx} = import '../transform.fnk'
 
 
 
@@ -33,12 +33,7 @@ block_statement = fn expr, ctx:
 
 exprs_block = fn exprs, ctx:
   pipe exprs:
-    # TODO: duplicate in other modules
-    map expr, expr_ctx=ctx:
-      [js_expr, next_ctx] = block_statement expr, expr_ctx
-      ([js_expr, next_ctx], next_ctx)
-
-    collect_with_ctx ctx
+    map_with_ctx ctx, block_statement
 
 
 

src/lang/call/call.fnk

@@ -2,26 +2,19 @@ babel_types = import '@babel/types'
 {callExpression, identifier} = babel_types
 {is_empty, length} = import '@fink/std-lib/iter.fnk'
 
-{transform, collect_with_ctx} = import '../transform.fnk'
+{transform, map_with_ctx} = import '../transform.fnk'
 
 
 
 transform_args = fn args, ctx:
-  [js_args, next_ctx] = pipe args:
-    map expr, arg_ctx=ctx:
-      [arg, next_ctx] = match expr:
+  pipe args:
+    map_with_ctx ctx, fn expr, arg_ctx:
+      match expr:
         {type: 'empty'}:
-          undef = identifier 'undefined'
-          [undef, ctx]
+          [(identifier 'undefined'), ctx]
         else:
           transform expr, arg_ctx
 
-      ([arg, next_ctx], next_ctx)
-
-    collect_with_ctx ctx
-
-  [js_args, next_ctx]
-
 
 
 transform_single_arg = fn [expr], ctx:

src/lang/call/pipe.fnk

@@ -2,37 +2,35 @@ babel_types = import '@babel/types'
 {callExpression} = babel_types
 {is_empty} = import '@fink/std-lib/iter.fnk'
 
-{assign, lets, expr_block, undef} = import '../../js/types.fnk'
+{assign, lets, expr_block, undef, unique_ident} = import '../../js/types.fnk'
 {transform_value} = import '../partial/init.fnk'
 {wrap_with_comment_loc} = import '../comments/init.fnk'
-{transform, collect_with_ctx} = import '../transform.fnk'
+{transform, map_with_ctx} = import '../transform.fnk'
 
 
 
 transform_pipe = fn node, ctx:
-  {unique_ident} = ctx
   {exprs} = node
 
-  [start_value, pipe_ctx] = match node.args:
+  [start_value, id_ctx] = match node.args:
     is_empty ?:
       [(undef _), ctx]
     else:
       [arg] = node.args
       transform arg, ctx
 
-  result = unique_ident 'pipe_result'
+  [result, pipe_ctx] = unique_ident 'pipe_result', id_ctx
 
   [pipe_calls, next_ctx] = pipe exprs:
-    map expr, callee_ctx=pipe_ctx:
+    map_with_ctx pipe_ctx, fn expr, callee_ctx:
       [callee, next_ctx] = transform_value expr, callee_ctx
 
       js = wrap_with_comment_loc
         assign result, callExpression callee, [result]
         expr
 
-      ([js, next_ctx], next_ctx)
+      [js, next_ctx]
 
-    collect_with_ctx ctx
 
   js = expr_block
     wrap_with_comment_loc