GraphQL lexer and parser (without optional type system)

ccan/graphql/LICENSE

+../../licenses/BSD-MIT
\ No newline at end of file

ccan/graphql/_info

+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * graphql - Routines to lex and parse GraphQL.
+ *
+ * This code contains routines to lex and parse GraphQL code.
+ * This code was written per the spec at:
+ *    https://spec.graphql.org/draft/
+ * ...dated Fri, May 21, 2021 at the time of writing.
+ *    Copyright (c) 2021 WhiteCloudFarm.org <robert.lee.dickinson@gmail.com>
+ *    <https://github.com/rl-d/ccan>
+ * 
+ * Example:
+ *	#include <stdio.h>
+ *	#include "ccan/graphql/graphql.h"
+ *	
+ *	int main(int argc, char *argv[])
+ *	
+ *		const char *input_string = "{ fieldName }";
+ *		struct list_head *output_tokens;
+ *		struct graphql_executable_document *output_document;
+ *	
+ *		const char *errmsg = graphql_lexparse(
+ *			input_string,
+ *			NULL, // tal context
+ *			&output_tokens, // variable to receive tokens
+ *			&output_document); // variable to receive AST
+ *	
+ *		if (errmsg) {
+ *			struct graphql_token *last_token;
+ *			last_token = list_tail(output_tokens, struct graphql_token, list);
+ *			printf("Line %d, col %d: %s",
+ *				last_token->source_line,
+ *				last_token->source_column + last_token->source_len,
+ *				errmsg);
+ *		} else {
+ *			// Normally you would check every indirection in the resulting AST for null
+ *			// pointers, but for simplicity of example:
+ *			printf("A field from the parsed string: %s\n",
+ *				output_document->first_def->op_def->sel_set->
+ *				first->field->name->token_string);
+ *		}
+ *	
+ *		output_tokens = tal_free(output_tokens);
+ *	}
+ *
+ * License: BSD-MIT
+ */
+int main(int argc, char *argv[])
+{
+	/* Expect exactly one argument */
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/list\n");
+		printf("ccan/take\n");
+		printf("ccan/tal\n");
+		printf("ccan/tal/str\n");
+		printf("ccan/utf8\n");
+		return 0;
+	}
+
+	return 1;
+}
+

ccan/graphql/graphql.h

+#ifndef __GRAPHQL_H__
+#define __GRAPHQL_H__ 1
+
+#include <stdio.h>
+
+#include <ccan/list/list.h>
+#include <ccan/tal/tal.h>
+
+// Coding constants
+#define GRAPHQL_SUCCESS 0
+
+// The following structures constitute the AST returned by the parser.
+
+struct graphql_directive {
+	struct graphql_directive *next;
+	struct graphql_token *name;
+	struct graphql_arguments *args;
+};
+
+struct graphql_directives {
+	struct graphql_directive *first;
+};
+
+struct graphql_named_type {
+	struct graphql_token *name;
+};
+
+struct graphql_type {
+	struct graphql_named_type *named;
+//	struct graphql_list_type *list;
+//	struct graphql_non_null_type *non_null;
+};
+
+struct graphql_default_value {
+	struct graphql_value *val;
+};
+
+struct graphql_variable_definition {
+	struct graphql_variable_definition *next;
+	struct graphql_variable *var;
+	struct graphql_type *type;
+	struct graphql_default_value *default_val;
+	struct graphql_directives *directives;
+};
+
+struct graphql_variable_definitions {
+	struct graphql_variable_definition *first;
+};
+
+struct graphql_variable {
+	struct graphql_token *name;
+};
+
+struct graphql_object_field {
+	struct graphql_object_field *next;
+	struct graphql_token *name;
+	struct graphql_value *val;
+};
+
+struct graphql_object_value {
+	struct graphql_object_field *first;
+};
+
+struct graphql_list_value {
+	struct graphql_token *val;
+};
+
+struct graphql_enum_value {
+	struct graphql_token *val;
+};
+
+struct graphql_null_value {
+	struct graphql_token *val;
+};
+
+struct graphql_string_value {
+	struct graphql_token *val;
+};
+
+struct graphql_boolean_value {
+	struct graphql_token *val;
+};
+
+struct graphql_float_value {
+	struct graphql_token *val;
+};
+
+struct graphql_int_value {
+	struct graphql_token *val;
+};
+
+struct graphql_value {
+	struct graphql_variable *var;
+	struct graphql_int_value *int_val;
+	struct graphql_float_value *float_val;
+	struct graphql_boolean_value *bool_val;
+	struct graphql_string_value *str_val;
+	struct graphql_null_value *null_val;
+	struct graphql_enum_value *enum_val;
+	struct graphql_list_value *list_val;
+	struct graphql_object_value *obj_val;
+};
+
+struct graphql_inline_fragment {
+	struct graphql_type_condition *type_cond;
+	struct graphql_directives *directives;
+	struct graphql_selection_set *sel_set;
+};
+
+struct graphql_type_condition {
+	struct graphql_named_type *named_type;
+};
+
+struct graphql_fragment_name {
+	struct graphql_token *name;
+};
+
+struct graphql_fragment_definition {
+	struct graphql_fragment_name *name;
+	struct graphql_type_condition *type_cond;
+	struct graphql_directives *directives;
+	struct graphql_selection_set *sel_set;
+};
+
+struct graphql_fragment_spread {
+	struct graphql_fragment_name *name;
+	struct graphql_directives *directives;
+};
+
+struct graphql_alias {
+	struct graphql_token *name;
+};
+
+struct graphql_argument {
+	struct graphql_argument *next;
+	struct graphql_token *name;
+	struct graphql_value *val;
+};
+
+struct graphql_arguments {
+	struct graphql_argument *first;
+};
+
+struct graphql_field {
+	struct graphql_alias *alias;
+	struct graphql_token *name;
+	struct graphql_arguments *args;
+	struct graphql_directives *directives;
+	struct graphql_selection_set *sel_set;
+};
+
+struct graphql_selection {
+	struct graphql_selection *next;
+	struct graphql_field *field;
+	struct graphql_fragment_spread *frag_spread;
+	struct graphql_inline_fragment *inline_frag;
+};
+
+struct graphql_selection_set {
+	struct graphql_selection *first;
+};
+
+struct graphql_operation_type {
+	struct graphql_token *op_type;
+};
+
+struct graphql_operation_definition {
+	struct graphql_operation_type *op_type;
+	struct graphql_token *op_name;
+	struct graphql_variable_definitions *vars;
+	struct graphql_directives *directives;
+	struct graphql_selection_set *sel_set;
+};
+
+struct graphql_executable_definition {
+	struct graphql_executable_definition *next_def;
+	struct graphql_operation_definition *op_def;
+	struct graphql_fragment_definition *frag_def;
+};
+
+struct graphql_executable_document {
+	struct graphql_executable_definition *first_def;
+};
+
+struct graphql_definition {
+	struct graphql_definition *next_def;
+	struct graphql_executable_definition *executable_def;
+	struct graphql_type_system_definition_or_extension *type_system_def;
+};
+
+struct graphql_document {
+	struct graphql_definition *first_def;
+};
+
+
+struct graphql_token {
+	struct list_node list;
+	unsigned int token_type;
+	unsigned int token_specific;
+	char *token_string;
+	unsigned int source_line;
+	unsigned int source_column;
+	unsigned int source_len;
+};
+
+/* The lexer.
+ * INPUTS:
+ *	input - string to parse
+ *	ctx - parent tal context or NULL
+ *	tokens - a variable to receive the resulting token list
+ * RETURN:
+ *	GRAPHQL_SUCCESS or an error string.
+ */
+const char *graphql_lex(const char *input, const tal_t *ctx, struct list_head **tokens);
+
+/* The parser.
+ * INPUTS:
+ *	tokens - the list produced by the lexer
+ *	doc - a variable to receive the resulting abstract syntax tree (AST)
+ * RETURN:
+ *	GRAPHQL_SUCCESS or an error string.
+ */
+const char *graphql_parse(struct list_head *tokens, struct graphql_executable_document **doc);
+
+/* The lexer and parser in one function, for convenience. */
+const char *graphql_lexparse(const char *input, const tal_t *ctx, struct list_head **tokens, struct graphql_executable_document **doc);
+
+#endif
+