Record fixity of call type in flags (#124)

We now record which precise call syntax was used out of the four
options:
* Prefix calls with parens
* Prefix operator calls
* Infix operator calls
* Postfix operator calls

This allows us to distinguish keyword arguments from assignment, fixing
several bugs with = to kw conversion.

Also, change to emit unadorned postfix adjoint as `(call-post x ')` rather
than as a syntactic operator `(' x)`, for consistency with suffixed
versions like `x'ᵀ`.

Author: c42f

src/expr.jl

@@ -99,46 +99,46 @@ function _to_expr(node::SyntaxNode; iteration_spec=false, need_linenodes=true,
         args[1] = _to_expr(node_args[1], need_linenodes=false)
         args[2] = _to_expr(node_args[2])
     else
-        eq_to_kw =  headsym == :call && !has_flags(node, INFIX_FLAG)  ||
-                    headsym == :ref                                   ||
-                   (headsym == :parameters && !inside_vect_or_braces) ||
-                   (headsym == :tuple && inside_dot_expr)
+        eq_to_kw_in_call =
+            headsym == :call && is_prefix_call(node)          ||
+            headsym == :ref
+        eq_to_kw_all = headsym == :parameters && !inside_vect_or_braces ||
+                      (headsym == :tuple && inside_dot_expr)
         in_dot = headsym == :.
         in_vb = headsym == :vect || headsym == :braces
-        if insert_linenums
-            if isempty(node_args)
-                push!(args, source_location(LineNumberNode, node.source, node.position))
-            else
-                for i in 1:length(node_args)
-                    n = node_args[i]
-                    args[2*i-1] = source_location(LineNumberNode, n.source, n.position)
-                    args[2*i] = _to_expr(n,
-                                         eq_to_kw=eq_to_kw,
-                                         inside_dot_expr=in_dot,
-                                         inside_vect_or_braces=in_vb)
-                end
-            end
+        if insert_linenums && isempty(node_args)
+            push!(args, source_location(LineNumberNode, node.source, node.position))
         else
             for i in 1:length(node_args)
-                args[i] = _to_expr(node_args[i],
-                                   eq_to_kw=eq_to_kw,
-                                   inside_dot_expr=in_dot,
-                                   inside_vect_or_braces=in_vb)
+                n = node_args[i]
+                if insert_linenums
+                    args[2*i-1] = source_location(LineNumberNode, n.source, n.position)
+                end
+                eq_to_kw = eq_to_kw_in_call && i > 1 || eq_to_kw_all
+                args[insert_linenums ? 2*i : i] =
+                    _to_expr(n, eq_to_kw=eq_to_kw,
+                             inside_dot_expr=in_dot,
+                             inside_vect_or_braces=in_vb)
             end
         end
     end
-    # Julia's standard `Expr` ASTs have children stored in a canonical
-    # order which is often not always source order. We permute the children
-    # here as necessary to get the canonical order.
-    if is_infix(node.raw)
-        args[2], args[1] = args[1], args[2]
-    end
 
     # Special cases for various expression heads
     loc = source_location(LineNumberNode, node.source, node.position)
     if headsym == :macrocall
         insert!(args, 2, loc)
     elseif headsym in (:call, :ref)
+        # Julia's standard `Expr` ASTs have children stored in a canonical
+        # order which is often not always source order. We permute the children
+        # here as necessary to get the canonical order.
+        if is_infix_op_call(node) || is_postfix_op_call(node)
+            args[2], args[1] = args[1], args[2]
+        end
+        # Lower (call x ') to special ' head
+        if is_postfix_op_call(node) && args[1] == Symbol("'")
+            popfirst!(args)
+            headsym = Symbol("'")
+        end
         # Move parameters block to args[2]
         if length(args) > 1 && Meta.isexpr(args[end], :parameters)
             insert!(args, 2, args[end])

src/parse_stream.jl

@@ -5,18 +5,25 @@
 # TODO: Use `primitive type SyntaxFlags 16 end` rather than an alias?
 const RawFlags = UInt16
 const EMPTY_FLAGS = RawFlags(0)
+# Applied to tokens which are syntax trivia after parsing
 const TRIVIA_FLAG = RawFlags(1<<0)
-# Some of the following flags are head-specific and could probably be allowed
-# to cover the same bits...
-const INFIX_FLAG  = RawFlags(1<<1)
-# Record whether syntactic operators were dotted
-const DOTOP_FLAG = RawFlags(1<<2)
+
+# Record whether operators are dotted
+const DOTOP_FLAG = RawFlags(1<<1)
+# Record whether operator has a suffix
+const SUFFIXED_FLAG        = RawFlags(1<<2)
+
+# Distinguish various syntaxes which are mapped to K"call"
+const PREFIX_CALL_FLAG = RawFlags(0<<3)
+const INFIX_FLAG       = RawFlags(1<<3)
+const PREFIX_OP_FLAG   = RawFlags(2<<3)
+const POSTFIX_OP_FLAG  = RawFlags(3<<3)
+
+# The next two bits could overlap with the previous two if necessary
 # Set when kind == K"String" was triple-delimited as with """ or ```
-const TRIPLE_STRING_FLAG = RawFlags(1<<3)
+const TRIPLE_STRING_FLAG = RawFlags(1<<5)
 # Set when a string or identifier needs "raw string" unescaping
-const RAW_STRING_FLAG = RawFlags(1<<4)
-# Record whether operator has a suffix
-const SUFFIXED_FLAG        = RawFlags(1<<6)
+const RAW_STRING_FLAG = RawFlags(1<<6)
 
 # Token-only flag
 # Record whether a token had preceding whitespace
@@ -34,6 +41,10 @@ function set_numeric_flags(n::Integer)
     f
 end
 
+function call_type_flags(f::RawFlags)
+    f & 0b11000
+end
+
 function numeric_flags(f::RawFlags)
     Int((f >> 8) % UInt8)
 end
@@ -70,7 +81,9 @@ function untokenize(head::SyntaxHead; unique=true, include_flag_suff=true)
     if include_flag_suff && suffix_flags != EMPTY_FLAGS
         str = str*"-"
         is_trivia(head)  && (str = str*"t")
-        is_infix(head)   && (str = str*"i")
+        is_infix_op_call(head)          && (str = str*"i")
+        is_prefix_op_call(head)  && (str = str*"pre")
+        is_postfix_op_call(head) && (str = str*"post")
         has_flags(head, TRIPLE_STRING_FLAG) && (str = str*"s")
         has_flags(head, RAW_STRING_FLAG) && (str = str*"r")
         is_suffixed(head) && (str = str*"S")
@@ -90,8 +103,13 @@ flags(x) = flags(head(x))
 
 # Predicates based on flags()
 has_flags(x, test_flags) = has_flags(flags(x), test_flags)
+call_type_flags(x) = call_type_flags(flags(x))
+
 is_trivia(x) = has_flags(x, TRIVIA_FLAG)
-is_infix(x)  = has_flags(x, INFIX_FLAG)
+is_prefix_call(x)     = call_type_flags(x) == PREFIX_CALL_FLAG
+is_infix_op_call(x)   = call_type_flags(x) == INFIX_FLAG
+is_prefix_op_call(x)  = call_type_flags(x) == PREFIX_OP_FLAG
+is_postfix_op_call(x) = call_type_flags(x) == POSTFIX_OP_FLAG
 is_dotted(x) = has_flags(x, DOTOP_FLAG)
 is_suffixed(x) = has_flags(x, SUFFIXED_FLAG)
 is_decorated(x) = is_dotted(x) || is_suffixed(x)

src/parser.jl

@@ -544,7 +544,7 @@ function parse_assignment_with_initial_ex(ps::ParseState, mark, down::T) where {
     if k == K"~"
         if ps.space_sensitive && !preceding_whitespace(peek_token(ps, 2))
             # Unary ~ in space sensitive context is not assignment precedence
-            # [a ~b]  ==>  (hcat a (call ~ b))
+            # [a ~b]  ==>  (hcat a (call-pre ~ b))
             return
         end
         # ~ is the only non-syntactic assignment-precedence operator.
@@ -885,8 +885,8 @@ function parse_with_chains(ps::ParseState, down, is_op, chain_ops)
                 is_both_unary_and_binary(t) &&
                 !preceding_whitespace(peek_token(ps, 2))
             # The following is two elements of a hcat
-            # [x +y]     ==>  (hcat x (call + y))
-            # [x+y +z]   ==>  (hcat (call-i x + y) (call + z))
+            # [x +y]     ==>  (hcat x (call-pre + y))
+            # [x+y +z]   ==>  (hcat (call-i x + y) (call-pre + z))
             # Conversely the following are infix calls
             # [x +₁y]    ==>  (vect (call-i x +₁ y))
             # [x+y+z]    ==>  (vect (call-i x + y z))
@@ -914,7 +914,7 @@ function parse_chain(ps::ParseState, down, op_kind)
         if ps.space_sensitive && preceding_whitespace(t) &&
             is_both_unary_and_binary(t) &&
             !preceding_whitespace(peek_token(ps, 2))
-            # [x +y]  ==>  (hcat x (call + y))
+            # [x +y]  ==>  (hcat x (call-pre + y))
             break
         end
         bump(ps, TRIVIA_FLAG)
@@ -948,16 +948,16 @@ function parse_unary_subtype(ps::ParseState)
         elseif k2 in KSet"{ ("
             # parse <:{T}(x::T) or <:(x::T) like other unary operators
             # <:{T}(x::T)  ==>  (call (curly <: T) (:: x T))
-            # <:(x::T)     ==>  (<: (:: x T))
+            # <:(x::T)     ==>  (<:-pre (:: x T))
             parse_where(ps, parse_juxtapose)
         else
-            # <: A where B  ==>  (<: (where A B))
+            # <: A where B  ==>  (<:-pre (where A B))
             mark = position(ps)
             bump(ps, TRIVIA_FLAG)
             parse_where(ps, parse_juxtapose)
             # Flisp parser handled this, but I don't know how it can happen...
             @check peek_behind(ps).kind != K"tuple"
-            emit(ps, mark, k)
+            emit(ps, mark, k, PREFIX_OP_FLAG)
         end
     else
         parse_where(ps, parse_juxtapose)
@@ -1015,7 +1015,7 @@ function is_juxtapose(ps, prev_k, t)
     # Not juxtaposition - parse_juxtapose will consume only the first token.
     # x.3       ==>  x
     # sqrt(2)2  ==>  (call sqrt 2)
-    # x' y      ==>  x
+    # x' y      ==>  (call-post x ')
     # x 'y      ==>  x
 
     return !preceding_whitespace(t)                         &&
@@ -1039,7 +1039,7 @@ end
 # 2(x)     ==>  (call-i 2 * x)
 # (2)(3)x  ==>  (call-i 2 * 3 x)
 # (x-1)y   ==>  (call-i (call-i x - 1) * y)
-# x'y      ==>  x
+# x'y      ==>  (call-i (call-post x ') * y)
 #
 # flisp: parse-juxtapose
 function parse_juxtapose(ps::ParseState)
@@ -1098,11 +1098,11 @@ function parse_unary(ps::ParseState)
             if is_prec_power(k3) || k3 in KSet"[ {"
                 # `[`, `{` (issue #18851) and `^` have higher precedence than
                 # unary negation
-                # -2^x      ==>  (call - (call-i 2 ^ x))
-                # -2[1, 3]  ==>  (call - (ref 2 1 3))
+                # -2^x      ==>  (call-pre - (call-i 2 ^ x))
+                # -2[1, 3]  ==>  (call-pre - (ref 2 1 3))
                 bump(ps)
                 parse_factor(ps)
-                emit(ps, mark, K"call")
+                emit(ps, mark, K"call", PREFIX_OP_FLAG)
             else
                 # We have a signed numeric literal. Glue the operator to the
                 # next token to create a signed literal:
@@ -1115,17 +1115,17 @@ function parse_unary(ps::ParseState)
         end
     end
     # Things which are not quite negative literals result in a unary call instead
-    # -0x1 ==>  (call - 0x01)
-    # - 2  ==>  (call - 2)
-    # .-2  ==>  (call .- 2)
+    # -0x1 ==>  (call-pre - 0x01)
+    # - 2  ==>  (call-pre - 2)
+    # .-2  ==>  (call-pre .- 2)
     parse_unary_call(ps)
 end
 
 # Parse calls to unary operators and prefix calls involving arbitrary operators
 # with bracketed arglists (as opposed to infix notation)
 #
-# +a      ==>  (call + a)
-# +(a,b)  ==>  (call + a b)
+# +a      ==>  (call-pre + a)
+# +(a,b)  ==>  (call-pre + a b)
 #
 # flisp: parse-unary-call
 function parse_unary_call(ps::ParseState)
@@ -1208,33 +1208,33 @@ function parse_unary_call(ps::ParseState)
         else
             # Unary function calls with brackets as grouping, not an arglist
             if opts.is_block
-                # +(a;b)   ==>  (call + (block a b))
+                # +(a;b)   ==>  (call-pre + (block a b))
                 emit(ps, mark_before_paren, K"block")
             end
             # Not a prefix operator call but a block; `=` is not `kw`
-            # +(a=1)  ==>  (call + (= a 1))
+            # +(a=1)  ==>  (call-pre + (= a 1))
             # Unary operators have lower precedence than ^
-            # +(a)^2  ==>  (call + (call-i a ^ 2))
-            # +(a)(x,y)^2  ==>  (call + (call-i (call a x y) ^ 2))
+            # +(a)^2  ==>  (call-pre + (call-i a ^ 2))
+            # +(a)(x,y)^2  ==>  (call-pre + (call-i (call a x y) ^ 2))
             parse_call_chain(ps, mark_before_paren)
             parse_factor_with_initial_ex(ps, mark_before_paren)
-            emit(ps, mark, op_node_kind)
+            emit(ps, mark, op_node_kind, PREFIX_OP_FLAG)
         end
     else
         if is_unary_op(op_t)
             # Normal unary calls
-            # +x  ==>  (call + x)
-            # √x  ==>  (call √ x)
-            # ±x  ==>  (call ± x)
+            # +x  ==>  (call-pre + x)
+            # √x  ==>  (call-pre √ x)
+            # ±x  ==>  (call-pre ± x)
             bump(ps, op_tok_flags)
         else
-            # /x     ==>  (call (error /) x)
-            # +₁ x   ==>  (call (error +₁) x)
-            # .<: x  ==>  (call (error .<:) x)
+            # /x     ==>  (call-pre (error /) x)
+            # +₁ x   ==>  (call-pre (error +₁) x)
+            # .<: x  ==>  (call-pre (error .<:) x)
             bump(ps, error="not a unary operator")
         end
         parse_unary(ps)
-        emit(ps, mark, op_node_kind)
+        emit(ps, mark, op_node_kind, PREFIX_OP_FLAG)
     end
 end
 
@@ -1433,6 +1433,8 @@ function parse_call_chain(ps::ParseState, mark, is_macrocall=false)
                 finish_macroname(ps, mark, valid_macroname, macro_name_position)
             end
             # f(a,b)  ==>  (call f a b)
+            # f(a; b=1)  ==>  (call f a (parameters (b 1)))
+            # (a=1)()  ==>  (call (= a 1))
             # f (a)  ==>  (call f (error-t) a b)
             bump_disallowed_space(ps)
             bump(ps, TRIVIA_FLAG)
@@ -1457,6 +1459,7 @@ function parse_call_chain(ps::ParseState, mark, is_macrocall=false)
                                       K"]", ps.end_symbol)
             # a[i]    ==>  (ref a i)
             # a[i,j]  ==>  (ref a i j)
+            # (a=1)[] ==>  (ref (= a 1))
             # T[x   y]  ==>  (typed_hcat T x y)
             # T[x ; y]  ==>  (typed_vcat T x y)
             # T[a b; c d]  ==>  (typed_vcat T (row a b) (row c d))
@@ -1562,15 +1565,10 @@ function parse_call_chain(ps::ParseState, mark, is_macrocall=false)
                 this_iter_valid_macroname = true
             end
         elseif k == K"'" && !preceding_whitespace(t)
-            if !is_suffixed(t)
-                # f'  ==> (' f)
-                bump(ps, TRIVIA_FLAG)
-                emit(ps, mark, k)
-            else
-                # f'ᵀ ==> (call 'ᵀ f)
-                bump(ps)
-                emit(ps, mark, K"call", INFIX_FLAG)
-            end
+            # f'  ==> (call-post f ')
+            # f'ᵀ ==> (call-post f 'ᵀ)
+            bump(ps)
+            emit(ps, mark, K"call", POSTFIX_OP_FLAG)
         elseif k == K"{"
             # Type parameter curlies and macro calls
             if is_macrocall

src/tokenize.jl

@@ -945,7 +945,6 @@ function lex_backslash(l::Lexer)
     return emit(l, K"\\")
 end
 
-# TODO .op
 function lex_dot(l::Lexer)
     if accept(l, '.')
         if accept(l, '.')