Add pbg and sha1

1 files changed, 239 insertions, 1 deletions

diff --git a/src/pbg.h b/src/pbg.h
index 36a1da6..98a3370 120000..100644
--- a/src/pbg.h
+++ b/src/pbg.h
@@ -1 +1,239 @@
-../pbg/pbg.h
\ No newline at end of file
+#ifndef __PBG_H__
+#define __PBG_H__
+
+/*********************************************************
+ *                                                       *
+ * Prefix Boolean Grammar (PBG), a lightweight C library *
+ * By Tyler J. Daddio, November 2018                     *
+ *                                                       *
+ *********************************************************/
+
+/* Used to suppress compiler warnings for intentionally unused arguments. This
+ * isn't as foolproof as GCC's unused attribute, but it is not compiler-
+ * dependent, which is just dandy. */
+#define PBG_UNUSED(x) (void)(x)
+
+/* Used to represent the result of an expression evaluation. */
+#define PBG_FALSE  0
+#define PBG_TRUE   1
+#define PBG_ERROR -1
+
+/*****************************
+ *                           *
+ * EXPRESSION REPRESENTATION *
+ *                           *
+ *****************************/
+
+/**
+ * Types of PBG fields.
+ */
+typedef enum {
+	PBG_NULL,  /* NULL: Unknown field type */
+	
+	/* Type literals. */
+	PBG_MIN_LT_TP,
+	PBG_LT_TP_DATE,    /* DATE TYPE literal */
+	PBG_LT_TP_BOOL,    /* TRUE/FALSE TYPE literal */
+	PBG_LT_TP_NUMBER,  /* NUMBER TYPE literal */
+	PBG_LT_TP_STRING,  /* STRING TYPE literal */
+	/* Add more TYPE literals here. */
+	PBG_MAX_LT_TP,
+	
+	/* Literals. */
+	PBG_MIN_LT,
+	PBG_LT_TRUE,    /* TRUE literal */
+	PBG_LT_FALSE,   /* FALSE literal */
+	PBG_LT_NUMBER,  /* NUMBER literal */
+	PBG_LT_STRING,  /* STRING literal */
+	PBG_LT_DATE,    /* DATE literal */
+	PBG_LT_VAR,     /* VARiable literal */
+	/* Add more literals here. */
+	PBG_MAX_LT,
+	
+	/* Operators. */
+	PBG_MIN_OP,
+	PBG_OP_NOT,   /* !   NOT */
+	PBG_OP_AND,   /* &   AND */
+	PBG_OP_OR,    /* |   OR */
+	PBG_OP_EQ,    /* =   EQUAL */
+	PBG_OP_LT,    /* <   LESS THAN */
+	PBG_OP_GT,    /* >   GREATER THAN */
+	PBG_OP_EXST,  /* ?   EXISTS */
+	PBG_OP_NEQ,   /* !=  NOT EQUAL */
+	PBG_OP_LTE,   /* <=  LESS THAN OR EQUAL TO */
+	PBG_OP_GTE,   /* >=  GREATER THAN OR EQUAL TO */
+	PBG_OP_TYPE,  /* @   TYPE OF */
+	/* Add more operators here. */
+	PBG_MAX_OP
+} pbg_field_type;
+
+/**
+ * This struct represents a PBG field. A field can be either a literal or an 
+ * operator. This is determined by its type. For operators, the data pointer
+ * describes a list of pointers to other fields in the abstract syntax tree.
+ * For constants, it describes data relevant to the field type.
+ */
+typedef struct {
+	pbg_field_type  _type;  /* Node type, determines the type/size of data. */
+	int             _int;   /* Type determines what this is used for! */
+	void*           _data;  /* Arbitrary data! */
+} pbg_field;
+
+/**
+ * This struct represents a PBG expression. There are two arrays in this 
+ * representation: one for constants, and one for variables. Both types are
+ * represented by fields. 
+ */
+typedef struct {
+	pbg_field*  _constants;  /* Constants. */
+	pbg_field*  _variables;  /* Variables. */
+	int         _numconst;   /* Number of constants. */
+	int         _numvars;    /* Number of variables. */
+} pbg_expr;
+
+
+/************************
+ *                      *
+ * ERROR REPRESENTATION *
+ *                      *
+ ************************/
+
+/**
+ * Type specifiers for all possible PBG errors.
+ */
+typedef enum {
+	PBG_ERR_NONE,
+	PBG_ERR_ALLOC,
+	PBG_ERR_STATE,
+	PBG_ERR_SYNTAX,
+	PBG_ERR_UNKNOWN_TYPE,
+	PBG_ERR_OP_ARITY,
+	PBG_ERR_OP_ARG_TYPE
+} pbg_error_type;
+
+/**
+ * Represents a PBG error. Errors may be generated during parsing and 
+ * evaluation and should be checked by the caller.
+ */
+typedef struct {
+	pbg_error_type  _type;  /* Error type. */
+	int             _line;  /* Line of file where error occurred. */
+	char*           _file;  /* File in which error occurred. */
+	int             _int;   /* Type determines what this is used for! */
+	void*           _data;  /* Data to be included with error report. */
+} pbg_error;
+
+
+/***************
+ *             *
+ * EXPRESSIONS *
+ *             *
+ ***************/
+
+/**
+ * Parses the string as a boolean expression in Prefix Boolean Grammar.
+ * @param e    PBG expression instance to initialize.
+ * @param err  Container to store error, if any occurs.
+ * @param str  String to parse. This must be terminated with '\0'.
+ */
+void pbg_parse(pbg_expr* e, pbg_error* err, char* str);
+
+/**
+ * Parses the string as a boolean expression in Prefix Boolean Grammar.
+ * @param e    PBG expression instance to initialize.
+ * @param err  Container to store error, if any occurs.
+ * @param str  String to parse.
+ * @param n    Length of the string.
+ */
+void pbg_parse_n(pbg_expr* e, pbg_error* err, char* str, int n);
+
+/**
+ * Evaluates the PBG expression with the provided assignments.
+ * @param e     PBG expression to evaluate.
+ * @param err   Container to store error, if any occurs.
+ * @param dict  Dictionary used to resolve VAR names.
+ * @return 1 if the PBG expression evaluates to true with the given dictionary. 
+ *         0 otherwise.
+ */
+int pbg_evaluate(pbg_expr* e, pbg_error* err, pbg_field (*dict)(char*, int));
+
+/**
+ * Destroys the PBG expression instance and frees all associated resources.
+ * This function does not free the provided pointer.
+ * @param e PBG expression to destroy.
+ */
+void pbg_free(pbg_expr* e);
+
+
+/**************
+ *            *
+ *   FIELDS   *
+ *            *
+ **************/
+
+/**
+ * Makes a field representing a DATE.
+ * @param year   Year of the date.
+ * @param month  Month of the date.
+ * @param day    Day of the date.
+ * @return a new DATE field.
+ */
+pbg_field pbg_make_date(int year, int month, int day);
+
+/**
+ * Makes a field representing a BOOL.
+ * @param truth   Truth value of the new BOOL.
+ * @return a new BOOL field.
+ */
+pbg_field pbg_make_bool(int truth);
+
+/**
+ * Makes a field representing a NUMBER.
+ * @param value   Numeric value of the NUMBER.
+ * @return a new NUMBER field.
+ */
+pbg_field pbg_make_number(double value);
+
+/**
+ * Makes a field representing a STRING.
+ * @param value   Value of the STRING.
+ * @return a new STRING field.
+ */
+pbg_field pbg_make_string(char* str);
+
+/**
+ * Makes a field representing NULL.
+ * @return a new NULL field.
+ */
+pbg_field pbg_make_null(void);
+
+
+/***************
+ *             *
+ *   ERRORS    *
+ *             *
+ ***************/
+
+/**
+ * Checks if the given error has been initialized with error data.
+ * @param err  Error to check.
+ * @return 1 if the given error has been initialized, 0 otherwise.
+ */
+int pbg_iserror(pbg_error* err);
+
+/**
+ * Prints a human-readable representation of the given pbg_error to the
+ * standard output.
+ * @param err  Error to print.
+ */
+void pbg_error_print(pbg_error* err);
+
+/**
+ * Frees resources being used by the given error, if any. This function does
+ * not free the provided pointer.
+ * @param e  PBG error to clean up.
+ */
+void pbg_error_free(pbg_error* e);
+
+
+#endif  /* __PBG_H__ */