From 25df438832be00de17400404efecd4b1939951b9 Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Sun, 17 Feb 2013 15:25:19 +0100
Subject: [PATCH] oops, moved files without adding

---
 src/glue.c | 170 ++++++++++++++++++++++++++++++++++++
 src/glue.h | 251 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 421 insertions(+)
 create mode 100644 src/glue.c
 create mode 100644 src/glue.h

diff --git a/src/glue.c b/src/glue.c
new file mode 100644
index 00000000..7f9c6fa4
--- /dev/null
+++ b/src/glue.c
@@ -0,0 +1,170 @@
+#include "glue.h"
+#include "../src/internal.h"  // for h_carray_*
+
+
+// The action equivalent of h_ignore.
+const HParsedToken *h_act_ignore(const HParseResult *p)
+{
+  return NULL;
+}
+
+// Helper to build HAction's that pick one index out of a sequence.
+const HParsedToken *h_act_index(int i, const HParseResult *p)
+{
+    if(!p) return NULL;
+
+    const HParsedToken *tok = p->ast;
+
+    if(!tok || tok->token_type != TT_SEQUENCE)
+        return NULL;
+
+    const HCountedArray *seq = tok->seq;
+    size_t n = seq->used;
+
+    if(i<0 || (size_t)i>=n)
+        return NULL;
+    else
+        return tok->seq->elements[i];
+}
+
+// Action version of h_seq_flatten.
+const HParsedToken *h_act_flatten(const HParseResult *p) {
+  return h_seq_flatten(p->arena, p->ast);
+}
+
+// Low-level helper for the h_make family.
+HParsedToken *h_make_(HArena *arena, HTokenType type)
+{
+  HParsedToken *ret = h_arena_malloc(arena, sizeof(HParsedToken));
+  ret->token_type = type;
+  return ret;
+}
+
+HParsedToken *h_make(HArena *arena, HTokenType type, void *value)
+{
+  assert(type >= TT_USER);
+  HParsedToken *ret = h_make_(arena, type);
+  ret->user = value;
+  return ret;
+}
+
+HParsedToken *h_make_seq(HArena *arena)
+{
+  HParsedToken *ret = h_make_(arena, TT_SEQUENCE);
+  ret->seq = h_carray_new(arena);
+  return ret;
+}
+
+HParsedToken *h_make_bytes(HArena *arena, size_t len)
+{
+  HParsedToken *ret = h_make_(arena, TT_BYTES);
+  ret->bytes.len = len;
+  ret->bytes.token = h_arena_malloc(arena, len);
+  return ret;
+}
+
+HParsedToken *h_make_sint(HArena *arena, int64_t val)
+{
+  HParsedToken *ret = h_make_(arena, TT_SINT);
+  ret->sint = val;
+  return ret;
+}
+
+HParsedToken *h_make_uint(HArena *arena, uint64_t val)
+{
+  HParsedToken *ret = h_make_(arena, TT_UINT);
+  ret->uint = val;
+  return ret;
+}
+
+// XXX -> internal
+HParsedToken *h_carray_index(const HCountedArray *a, size_t i)
+{
+  assert(i < a->used);
+  return a->elements[i];
+}
+
+size_t h_seq_len(const HParsedToken *p)
+{
+  assert(p != NULL);
+  assert(p->token_type == TT_SEQUENCE);
+  return p->seq->used;
+}
+
+HParsedToken **h_seq_elements(const HParsedToken *p)
+{
+  assert(p != NULL);
+  assert(p->token_type == TT_SEQUENCE);
+  return p->seq->elements;
+}
+
+HParsedToken *h_seq_index(const HParsedToken *p, size_t i)
+{
+  assert(p != NULL);
+  assert(p->token_type == TT_SEQUENCE);
+  return h_carray_index(p->seq, i);
+}
+
+HParsedToken *h_seq_index_path(const HParsedToken *p, size_t i, ...)
+{
+  va_list va;
+
+  va_start(va, i);
+  HParsedToken *ret = h_seq_index_vpath(p, i, va);
+  va_end(va);
+
+  return ret;
+}
+
+HParsedToken *h_seq_index_vpath(const HParsedToken *p, size_t i, va_list va)
+{
+  HParsedToken *ret = h_seq_index(p, i);
+  int j;
+
+  while((j = va_arg(va, int)) >= 0)
+    ret = h_seq_index(p, j);
+
+  return ret;
+}
+
+void h_seq_snoc(HParsedToken *xs, const HParsedToken *x)
+{
+  assert(xs != NULL);
+  assert(xs->token_type == TT_SEQUENCE);
+
+  h_carray_append(xs->seq, (HParsedToken *)x);
+}
+
+void h_seq_append(HParsedToken *xs, const HParsedToken *ys)
+{
+  assert(xs != NULL);
+  assert(xs->token_type == TT_SEQUENCE);
+  assert(ys != NULL);
+  assert(ys->token_type == TT_SEQUENCE);
+
+  for(size_t i; i<ys->seq->used; i++)
+    h_carray_append(xs->seq, ys->seq->elements[i]);
+}
+
+// Flatten nested sequences. Always returns a sequence.
+// If input element is not a sequence, returns it as a singleton sequence.
+const HParsedToken *h_seq_flatten(HArena *arena, const HParsedToken *p)
+{
+  assert(p != NULL);
+
+  HParsedToken *ret = h_make_seq(arena);
+  switch(p->token_type) {
+  case TT_SEQUENCE:
+    // Flatten and append all.
+    for(size_t i; i<p->seq->used; i++) {
+      h_seq_append(ret, h_seq_flatten(arena, h_seq_index(p, i)));
+    }
+    break;
+  default:
+    // Make singleton sequence.
+    h_seq_snoc(ret, p);
+    break;
+  }
+
+  return ret;
+}
diff --git a/src/glue.h b/src/glue.h
new file mode 100644
index 00000000..90944ea0
--- /dev/null
+++ b/src/glue.h
@@ -0,0 +1,251 @@
+//
+// API additions for writing grammar and semantic actions more concisely
+//
+//
+// Quick Overview:
+//
+// Grammars can be succinctly specified with the family of H_RULE macros.
+// H_RULE defines a plain parser variable. H_ARULE additionally attaches a
+// semantic action; H_VRULE attaches a validation. H_AVRULE and H_VARULE
+// combine both.
+//
+// A few standard semantic actions are defined below. The H_ACT_APPLY macro
+// allows semantic actions to be defined by "partial application" of
+// a generic action to fixed paramters.
+//
+// The definition of more complex semantic actions will usually consist of
+// extracting data from the given parse tree and constructing a token of custom
+// type to represent the result. A number of functions and convenience macros
+// are provided to capture the most common cases and idioms.
+//
+// See the leading comment blocks on the sections below for more details.
+//
+
+#ifndef HAMMER_GLUE__H
+#define HAMMER_GLUE__H
+
+#include <assert.h>
+#include "hammer.h"
+
+
+//
+// Grammar specification
+//
+// H_RULE is simply a short-hand for the typical declaration and definition of
+// a parser variable. See its plain definition below. The goal is to save
+// horizontal space as well as to provide a clear and unified look together with
+// the other macro variants that stays close to an abstract PEG or BNF grammar.
+// The latter goal is more specifically enabled by H_ARULE, H_VRULE, and their
+// combinations as they allow the definition of syntax to be given without
+// intermingling it with the semantic specifications.
+//
+// H_ARULE defines a variable just like H_RULE but attaches a semantic action
+// to the result of the parser via h_action. The action is expected to be
+// named act_<rulename>.
+//
+// H_VRULE is analogous to H_ARULE but attaches a validation via h_attr_bool.
+// The validation is expected to be named validate_<rulename>.
+//
+// H_VARULE combines H_RULE with both an action and a validation. The action is
+// attached before the validation, i.e. the validation receives as input the
+// result of the action.
+//
+// H_AVRULE is like H_VARULE but the action is attached outside the validation,
+// i.e. the validation receives the uninterpreted AST as input.
+//
+
+
+#define H_RULE(rule, def) const HParser *rule = def
+#define H_ARULE(rule, def) const HParser *rule = h_action(def, act_ ## rule)
+#define H_VRULE(rule, def) const HParser *rule = \
+  h_attr_bool(def, validate_ ## rule)
+#define H_VARULE(rule, def) const HParser *rule = \
+  h_attr_bool(h_action(def, act_ ## rule), validate_ ## rule)
+#define H_AVRULE(rule, def) const HParser *rule = \
+  h_action(h_attr_bool(def, validate_ ## rule), act_ ## rule)
+
+
+//
+// Pre-fab semantic actions
+//
+// A collection of generally useful semantic actions is provided.
+//
+// h_act_ignore is the action equivalent of the parser combinator h_ignore. It
+// simply causes the AST it is applied to to be replaced with NULL. This most
+// importantly causes it to be elided from the result of a surrounding
+// h_sequence.
+//
+// h_act_index is of note as it is not itself suitable to be passed to
+// h_action. It is parameterized by an index to be picked from a sequence
+// token. It must be wrapped in a proper HAction to be used. The H_ACT_APPLY
+// macro provides a concise way to define such a parameter-application wrapper.
+//
+// h_act_flatten acts on a token of possibly nested sequences by recursively
+// flattening it into a single sequence. Cf. h_seq_flatten below.
+//
+// H_ACT_APPLY implements "partial application" for semantic actions. It
+// defines a new action that supplies given parameters to a parameterized
+// action such as h_act_index.
+//
+
+const HParsedToken *h_act_ignore(const HParseResult *p);
+const HParsedToken *h_act_index(int i, const HParseResult *p);
+const HParsedToken *h_act_flatten(const HParseResult *p);
+
+// Define 'myaction' as a specialization of 'paction' by supplying the leading
+// parameters.
+#define H_ACT_APPLY(myaction, paction, ...) \
+  const HParsedToken *myaction(const HParseResult *p) { \
+    return paction(__VA_ARGS__, p); \
+  }
+
+
+//
+// Working with HParsedTokens
+//
+// The type HParsedToken represents a dynamically-typed universe of values.
+// Declared below are constructors to turn ordinary values into their
+// HParsedToken equivalents, extractors to retrieve the original values from
+// inside an HParsedToken, and functions that inspect and modify tokens of
+// sequence type directly.
+//
+// In addition, there are a number of short-hand macros that work with some
+// conventions to eliminate common boilerplate. These conventions are listed
+// below. Be sure to follow them if you want to use the respective macros.
+//
+//  * The single argument to semantic actions should be called 'p'.
+//
+//    The H_MAKE macros suppy 'p->arena' to their underlying h_make
+//    counterparts. The H_FIELD macros supply 'p->ast' to their underlying
+//    H_INDEX counterparts.
+//
+//  * For each custom token type, there should be a typedef for the
+//    corresponding value type.
+//
+//    H_CAST, H_INDEX and H_FIELD cast the void * user field of such a token to
+//    a pointer to the given type. 
+//
+//  * For each custom token type, say 'foo_t', there must be an integer
+//    constant 'TT_foo_t' to identify the token type. This constant must have a
+//    value greater or equal than TT_USER.
+//
+//    One idiom is to define an enum for all custom token types and to assign a
+//    value of TT_USER to the first element. This can be viewed as extending
+//    the HTokenType enum.
+//
+//    The H_MAKE and H_ASSERT macros derive the name of the token type constant
+//    from the given type name.
+//
+//
+// The H_ALLOC macro is useful for allocating values of custom token types.
+//
+// The H_MAKE family of macros construct tokens of a given type. The native
+// token types are indicated by a corresponding suffix such as in H_MAKE_SEQ.
+// The form with no suffix is used for custom token types. This convention is
+// also used for other macro and function families.
+//
+// The H_ASSERT family simply asserts that a given token has the expected type.
+// It mainly serves as an implementation aid for H_CAST. Of note in that regard
+// is that, unlike the standard 'assert' macro, these form _expressions_ that
+// return the value of their token argument; thus they can be used in a
+// "pass-through" fashion inside other expressions.
+//
+// The H_CAST family combines a type assertion with access to the
+// statically-typed value inside a token.
+//
+// A number of functions h_seq_* operate on and inspect sequence tokens.
+// Note that H_MAKE_SEQ takes no arguments and constructs an empty sequence.
+// Therefore there are h_seq_snoc and h_seq_append to build up sequences.
+//
+// The macro families H_FIELD and H_INDEX combine index access on a sequence
+// with a cast to the appropriate result type. H_FIELD is used to access the
+// elements of the argument token 'p' in an action. H_INDEX allows any sequence
+// token to be specified. Both macro families take an arbitrary number of index
+// arguments, giving access to elements in nested sequences by path.
+// These macros are very useful to avoid spaghetti chains of unchecked pointer
+// dereferences.
+//
+
+// Standard short-hand for arena-allocating a variable in a semantic action.
+#define H_ALLOC(TYP)  ((TYP *) h_arena_malloc(p->arena, sizeof(TYP)))
+
+// Token constructors...
+
+HParsedToken *h_make(HArena *arena, HTokenType type, void *value);
+HParsedToken *h_make_seq(HArena *arena);  // Makes empty sequence.
+HParsedToken *h_make_bytes(HArena *arena, size_t len);
+HParsedToken *h_make_sint(HArena *arena, int64_t val);
+HParsedToken *h_make_uint(HArena *arena, uint64_t val);
+
+// Standard short-hands to make tokens in an action.
+#define H_MAKE(TYP, VAL)  h_make(p->arena, TT_ ## TYP, VAL)
+#define H_MAKE_SEQ()      h_make_seq(p->arena)
+#define H_MAKE_BYTES(LEN) h_make_bytes(p->arena, LEN)
+#define H_MAKE_SINT(VAL)  h_make_sint(p->arena, VAL)
+#define H_MAKE_UINT(VAL)  h_make_uint(p->arena, VAL)
+
+// Extract (cast) type-specific value back from HParsedTokens...
+
+// Pass-through assertion that a given token has the expected type.
+#define h_assert_type(T,P)  (assert(P->token_type == (HTokenType)T), P)
+
+// Convenience short-hand forms of h_assert_type.
+#define H_ASSERT(TYP, TOK)   h_assert_type(TT_ ## TYP, TOK)
+#define H_ASSERT_SEQ(TOK)    h_assert_type(TT_SEQUENCE, TOK)
+#define H_ASSERT_BYTES(TOK)  h_assert_type(TT_BYTES, TOK)
+#define H_ASSERT_SINT(TOK)   h_assert_type(TT_SINT, TOK)
+#define H_ASSERT_UINT(TOK)   h_assert_type(TT_UINT, TOK)
+
+// Assert expected type and return contained value.
+#define H_CAST(TYP, TOK)   ((TYP *) H_ASSERT(TYP, TOK)->user)
+#define H_CAST_SEQ(TOK)    (H_ASSERT_SEQ(TOK)->seq)
+#define H_CAST_BYTES(TOK)  (H_ASSERT_BYTES(TOK)->bytes)
+#define H_CAST_SINT(TOK)   (H_ASSERT_SINT(TOK)->sint)
+#define H_CAST_UINT(TOK)   (H_ASSERT_UINT(TOK)->uint)
+
+// Sequence access...
+
+// Return the length of a sequence.
+size_t h_seq_len(const HParsedToken *p);
+
+// Access a sequence's element array.
+HParsedToken **h_seq_elements(const HParsedToken *p);
+
+// Access a sequence element by index.
+HParsedToken *h_seq_index(const HParsedToken *p, size_t i);
+
+// Access an element in a nested sequence by a path of indices.
+HParsedToken *h_seq_index_path(const HParsedToken *p, size_t i, ...);
+HParsedToken *h_seq_index_vpath(const HParsedToken *p, size_t i, va_list va);
+
+// Convenience macros combining (nested) index access and h_cast.
+#define H_INDEX(TYP, SEQ, ...)   H_CAST(TYP, H_INDEX_TOKEN(SEQ, __VA_ARGS__))
+#define H_INDEX_SEQ(SEQ, ...)    H_CAST_SEQ(H_INDEX_TOKEN(SEQ, __VA_ARGS__))
+#define H_INDEX_BYTES(SEQ, ...)  H_CAST_BYTES(H_INDEX_TOKEN(SEQ, __VA_ARGS__))
+#define H_INDEX_SINT(SEQ, ...)   H_CAST_SINT(H_INDEX_TOKEN(SEQ, __VA_ARGS__))
+#define H_INDEX_UINT(SEQ, ...)   H_CAST_UINT(H_INDEX_TOKEN(SEQ, __VA_ARGS__))
+#define H_INDEX_TOKEN(SEQ, ...)  h_seq_index_path(SEQ, __VA_ARGS__, -1)
+
+// Standard short-hand to access and cast elements on a sequence token.
+#define H_FIELD(TYP, ...)  H_INDEX(TYP, p->ast, __VA_ARGS__)
+#define H_FIELD_SEQ(...)   H_INDEX_SEQ(p->ast, __VA_ARGS__)
+#define H_FIELD_BYTES(...) H_INDEX_BYTES(p->ast, __VA_ARGS__)
+#define H_FIELD_SINT(...)  H_INDEX_SINT(p->ast, __VA_ARGS__)
+#define H_FIELD_UINT(...)  H_INDEX_UINT(p->ast, __VA_ARGS__)
+
+// Lower-level helper for h_seq_index.
+HParsedToken *h_carray_index(const HCountedArray *a, size_t i); // XXX -> internal
+
+// Sequence modification...
+
+// Add elements to a sequence.
+void h_seq_snoc(HParsedToken *xs, const HParsedToken *x);     // append one
+void h_seq_append(HParsedToken *xs, const HParsedToken *ys);  // append many
+
+// XXX TODO: Remove elements from a sequence.
+
+// Flatten nested sequences into one.
+const HParsedToken *h_seq_flatten(HArena *arena, const HParsedToken *p);
+
+
+#endif
-- 
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