fix: Always compute cells without clocked expressions using current values #91
16
NEWS
16
NEWS
@ -6,6 +6,13 @@ The changes compared to 2.3.0 are:
|
||||
o Added examples updating the life simulation to illustrate the color and
|
||||
computed style features.
|
||||
o You can compute the styles for cells, with an additional expression per cell.
|
||||
o Computation of current values for cells without clocked expressions now
|
||||
always depends on contemporaneous current values rather than prior values,
|
||||
even when the sheet is clocked. This means, for example, an entry whose base
|
||||
value is the sum of a column and which has no will always resolve to the
|
||||
current sum of that column, even if the column contains clocked values.
|
||||
(This is a breaking change in that prior to this modification, such a cell
|
||||
when clocked would contain the sum of the prior values in that column.)
|
||||
o New token types: style and bool.
|
||||
o Comparison operators return bool rather than int (Note this can be a breaking
|
||||
change; you may need to wrap comparisons in int() if you are using the result
|
||||
@ -21,8 +28,13 @@ o Addition of hexact float format, which allows for exact round trips to ASCII
|
||||
o New token type: funcall (which basically amounts to an expression). This
|
||||
allows parsed rather than unparsed expressions to be stored in cells, and
|
||||
allows macros which receive their arguments unevaluated.
|
||||
o sum(), min(), and max() can now operate over their list of arguments as well
|
||||
as over a block.
|
||||
o New region/accumulator operation count() that counts truthy cells (rather
|
||||
that just nonempty cells as n() does) added.
|
||||
o All region/accumulator operations including sum(), min(), and max() can
|
||||
now operate over their list of arguments as well as over a block.
|
||||
o All region/accumulator operations can take an optional expression when
|
||||
operating over a block that generates the values to be accumulated (rather
|
||||
than just taking the values directly from the block).
|
||||
o Added floor(), ceil(), trunc(), and round() functions for finding integers
|
||||
associated with doubles, eliminating (note possible breaking change) the
|
||||
int conversion with two rounding directions.
|
||||
|
164
doc/teapot.lyx
164
doc/teapot.lyx
@ -346,7 +346,7 @@ name "fig:Three-Dimensional-Spread-Sheet"
|
||||
|
||||
\end_inset
|
||||
|
||||
Three-Dimensional Spread Sheet Layout
|
||||
Three-Dimensional Spreadsheet Layout
|
||||
\end_layout
|
||||
|
||||
\end_inset
|
||||
@ -5315,34 +5315,170 @@ goto
|
||||
5.12.4
|
||||
\emph default
|
||||
.
|
||||
|
||||
\end_layout
|
||||
|
||||
\begin_layout Section
|
||||
Expressions
|
||||
Sheets, Cells, and Clocking
|
||||
\end_layout
|
||||
|
||||
\begin_layout Standard
|
||||
Cells consist of a base (reset) expression, a clocked expression, a style
|
||||
expression, and a current value.
|
||||
If the sheet is currently in the reset state (the default), all cells display
|
||||
their base value as current value.
|
||||
A
|
||||
\emph on
|
||||
sheet
|
||||
\emph default
|
||||
is a three-dimensional collection of
|
||||
\emph on
|
||||
cells
|
||||
\emph default
|
||||
.
|
||||
The slices in the X, Y, and Z directions are called the
|
||||
\emph on
|
||||
columns
|
||||
\emph default
|
||||
,
|
||||
\emph on
|
||||
rows
|
||||
\emph default
|
||||
, and
|
||||
\emph on
|
||||
layers
|
||||
\emph default
|
||||
, respectively.
|
||||
At any given time, the valid coordinates for a sheet are all non-negative
|
||||
integers up to some current limit in each of the X, Y, and Z directions,
|
||||
which may be different in each direction.
|
||||
Generally speaking, direct references to cells with negative coordinates
|
||||
are an error, whereas indirect references to cells with negative coordinates
|
||||
and all references to cells with coordinates beyond the current limits
|
||||
act as references to empty cells with all default attributes/styles.
|
||||
\end_layout
|
||||
|
||||
\begin_layout Standard
|
||||
When the sheet is clocked (see Table
|
||||
Each cell has three expressions, all of which are optional: a base (reset)
|
||||
expression, a clocked expression, and a style expression.
|
||||
It also has an associated current value.
|
||||
See section
|
||||
\begin_inset CommandInset ref
|
||||
LatexCommand ref
|
||||
reference "sec:Expressions"
|
||||
plural "false"
|
||||
caps "false"
|
||||
noprefix "false"
|
||||
|
||||
\end_inset
|
||||
|
||||
for the semantics of expressions and values.
|
||||
When the sheet is in the reset state (the default/initial state), all cells
|
||||
set their current values to the value of their base expression; references
|
||||
to other cells use those other cells' current values.
|
||||
The recomputation of current values updates referred-to cells first in
|
||||
an effort to produce the expected, correct values.
|
||||
However, if there are circular references among cells, this update process
|
||||
does not attempt to produce a fully self-consistent state, in that a given
|
||||
cell is only updated once.
|
||||
Hence the resulting current values can depend on the order updates occur,
|
||||
and it may happen that a cell's current value is not equal to the value
|
||||
of its base expression computed with current values of all cells.
|
||||
This behavior may seem problematic, but in fact it's not always possible
|
||||
to produce a self-consistent state.
|
||||
The simplest example is if the base expression for the cell with coordinates
|
||||
(0,0,0) is @(0,0,0)+1, since no number is one more than itself.
|
||||
Moreover, in the absence of circular reference chains among the base expression
|
||||
s, the recomputation of current values is guaranteed to reach a consistent
|
||||
state for all cells.
|
||||
The bottom line is that although circular references in base expressions
|
||||
are not disallowed, their utility may be limited because their behavior
|
||||
is relatively unpredictable.
|
||||
\end_layout
|
||||
|
||||
\begin_layout Standard
|
||||
When a sheet is clocked (see Table
|
||||
\begin_inset CommandInset ref
|
||||
LatexCommand ref
|
||||
reference "tab:Key-Bindings-in"
|
||||
|
||||
\end_inset
|
||||
|
||||
), the clocked expression is evaluated, using the current value of referenced
|
||||
cells.
|
||||
The new current value is the result of that evaluation.
|
||||
), every cell with a clocked expression is clocked.
|
||||
When a cell is clocked (either because the sheet was clocked or by virtue
|
||||
of the clock() function documented in section
|
||||
\begin_inset CommandInset ref
|
||||
LatexCommand ref
|
||||
reference "subsec:All-other-functions"
|
||||
plural "false"
|
||||
caps "false"
|
||||
noprefix "false"
|
||||
|
||||
\end_inset
|
||||
|
||||
), its clocked expression is evaluated using the current value of all cells
|
||||
referenced directly or indirectly, including cells that are also currently
|
||||
being clocked.
|
||||
Then the new current value of (all of the) clocked cell(s) is set to the
|
||||
result of that evaluation.
|
||||
Finally, the current values of the unclocked cells (which include any cells
|
||||
that have no clocked expression) are recomputed based on the new current
|
||||
values.
|
||||
The upshot of these rules is that one can control the updating of potentially
|
||||
circular references precisely: the computation of clocked expressions always
|
||||
uses values of all cells, including other clocked cells, from the previous
|
||||
|
||||
\begin_inset Quotes eld
|
||||
\end_inset
|
||||
|
||||
tick
|
||||
\begin_inset Quotes erd
|
||||
\end_inset
|
||||
|
||||
, and the computation of base expressions uses values of all cells, including
|
||||
other unclocked cells, from the current tick.
|
||||
\end_layout
|
||||
|
||||
\begin_layout Standard
|
||||
Finally, whenever the style of a given cell is needed, for example to display
|
||||
the cell, its style expression is evaluated based on the current values
|
||||
of all cells to which it refers directly or indirectly.
|
||||
The expression must evaluate to a style value (see subsection
|
||||
\begin_inset CommandInset ref
|
||||
LatexCommand ref
|
||||
reference "subsec:Data-Types"
|
||||
plural "false"
|
||||
caps "false"
|
||||
noprefix "false"
|
||||
|
||||
\end_inset
|
||||
|
||||
) and that value provides the style of the cell.
|
||||
\end_layout
|
||||
|
||||
\begin_layout Section
|
||||
\begin_inset CommandInset label
|
||||
LatexCommand label
|
||||
name "sec:Expressions"
|
||||
|
||||
\end_inset
|
||||
|
||||
Expressions and values
|
||||
\end_layout
|
||||
|
||||
\begin_layout Standard
|
||||
In
|
||||
\noun on
|
||||
teapot
|
||||
\noun default
|
||||
, values are specific data items and expressions are the formulas that can
|
||||
be evaluated to produce those values.
|
||||
This section describes the possible values, the allowed syntax of expressions,
|
||||
and the semantics of valid expressions.
|
||||
\end_layout
|
||||
|
||||
\begin_layout Subsection
|
||||
\begin_inset CommandInset label
|
||||
LatexCommand label
|
||||
name "subsec:Data-Types"
|
||||
|
||||
\end_inset
|
||||
|
||||
Data Types
|
||||
\end_layout
|
||||
|
||||
@ -6996,6 +7132,12 @@ sum Returns the sum of the accumulated values (recall for strings this is
|
||||
\end_layout
|
||||
|
||||
\begin_layout Subsubsection
|
||||
\begin_inset CommandInset label
|
||||
LatexCommand label
|
||||
name "subsec:All-other-functions"
|
||||
|
||||
\end_inset
|
||||
|
||||
All other functions
|
||||
\end_layout
|
||||
|
||||
|
@ -50,6 +50,11 @@ Token gettok(const Cell *cell, TokVariety v)
|
||||
return cell->tok[v];
|
||||
}
|
||||
|
||||
/* iterable -- does cell have iteration content? */
|
||||
bool iterable(const Cell* cell) {
|
||||
return (cell != NULLCELL) && cell->tok[ITER_CONT].type != EMPTY;
|
||||
}
|
||||
|
||||
/* locked -- is cell locked? */
|
||||
bool locked(const Cell *cell)
|
||||
{
|
||||
|
@ -32,6 +32,7 @@ typedef struct
|
||||
typedef enum {ALTER_LABEL, PRESERVE_LABEL} LabelHandling;
|
||||
|
||||
Token gettok(const Cell *cell, TokVariety v);
|
||||
bool iterable(const Cell *cell);
|
||||
bool locked(const Cell *cell);
|
||||
bool ignored(const Cell *cell);
|
||||
const char *getlabel(const Cell *cell);
|
||||
|
@ -692,6 +692,7 @@ void update(Sheet *sheet)
|
||||
upd_clock = true;
|
||||
recompvalue(sheet, w);
|
||||
}
|
||||
bool current_changed = false;
|
||||
for (ALL_CELLS_IN_SHEET(sheet,i,cell))
|
||||
{
|
||||
if (cell && cell->clock_resolving)
|
||||
@ -699,7 +700,25 @@ void update(Sheet *sheet)
|
||||
tfree(&(cell->tok[CURR_VAL]));
|
||||
cell->tok[CURR_VAL] = cell->tok[RES_VAL];;
|
||||
cell->tok[RES_VAL].type = EMPTY;
|
||||
current_changed = true;
|
||||
}
|
||||
}
|
||||
if (current_changed) {
|
||||
/* Recompute all of the non-clocked cells so that they get the values
|
||||
of the newly-changed clocked cells
|
||||
*/
|
||||
for (ALL_CELLS_IN_SHEET(sheet, i, cell)) {
|
||||
if (cell) {
|
||||
if (cell->clock_resolving) {
|
||||
cell->clock_resolving = false;
|
||||
} else {
|
||||
cell->updated = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
for (ALL_LOCS_IN_SHEET(sheet, w)) {
|
||||
upd_clock = true;
|
||||
recompvalue(sheet, w);
|
||||
}
|
||||
}
|
||||
upd_clock = false;
|
||||
@ -906,9 +925,10 @@ void clk(Sheet *sheet, const Location at)
|
||||
assert(sheet != (Sheet*)0);
|
||||
assert(IN_OCTANT(at));
|
||||
assert(LOC_WITHIN(sheet, at));
|
||||
if (CELL_AT(sheet,at))
|
||||
Cell* toclock = CELL_AT(sheet, at);
|
||||
if (iterable(toclock))
|
||||
{
|
||||
CELL_AT(sheet,at)->clock_requested = true;
|
||||
toclock->clock_requested = true;
|
||||
sheet->clk = true;
|
||||
}
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user