chore: recursively substitute signals for expressions

src/compile/buildmodel.ts

@@ -1,4 +1,4 @@
-import type {SignalRef} from 'vega';
+import type {ExprRef, SignalRef} from 'vega';
 import {Config} from '../config';
 import * as log from '../log';
 import {isAnyConcatSpec, isFacetSpec, isLayerSpec, isUnitSpec, LayoutSizeMixins, NormalizedSpec} from '../spec';
@@ -7,9 +7,10 @@ import {FacetModel} from './facet';
 import {LayerModel} from './layer';
 import {Model} from './model';
 import {UnitModel} from './unit';
+import {SubstituteType} from '../vega.schema';
 
 export function buildModel(
-  spec: NormalizedSpec,
+  spec: SubstituteType<NormalizedSpec, ExprRef, SignalRef>,
   parent: Model,
   parentGivenName: string,
   unitSize: LayoutSizeMixins,
@@ -19,7 +20,7 @@ export function buildModel(
     return new FacetModel(spec, parent, parentGivenName, config);
   } else if (isLayerSpec(spec)) {
     return new LayerModel(spec, parent, parentGivenName, unitSize, config);
-  } else if (isUnitSpec(spec)) {
+  } else if (isUnitSpec<SignalRef>(spec)) {
     return new UnitModel(spec, parent, parentGivenName, unitSize, config);
   } else if (isAnyConcatSpec(spec)) {
     return new ConcatModel(spec, parent, parentGivenName, config);

src/compile/compile.ts

@@ -20,6 +20,7 @@ import {buildModel} from './buildmodel';
 import {assembleRootData} from './data/assemble';
 import {optimizeDataflow} from './data/optimize';
 import {Model} from './model';
+import {deepReplaceExprRef} from '../expr';
 
 export interface CompileOptions {
   /**
@@ -89,7 +90,8 @@ export function compile(inputSpec: TopLevelSpec, opt: CompileOptions = {}) {
 
     // - Decompose all extended unit specs into composition of unit spec. For example, a box plot get expanded into multiple layers of bars, ticks, and rules. The shorthand row/column channel is also expanded to a facet spec.
     // - Normalize autosize and width or height spec
-    const spec = normalize(inputSpec, config);
+    const normalized = normalize(inputSpec, config);
+    const spec = deepReplaceExprRef(normalized) as any;
 
     // 3. Build Model: normalized spec -> Model (a tree structure)
 
@@ -128,7 +130,7 @@ export function compile(inputSpec: TopLevelSpec, opt: CompileOptions = {}) {
 
     return {
       spec: vgSpec,
-      normalized: spec
+      normalized
     };
   } finally {
     // Reset the singleton logger if a logger is provided

src/compile/concat.ts

@@ -1,9 +1,9 @@
-import {NewSignal, SignalRef} from 'vega';
+import {ExprRef, NewSignal, SignalRef} from 'vega';
 import {Config} from '../config';
 import * as log from '../log';
 import {isHConcatSpec, isVConcatSpec, NormalizedConcatSpec, NormalizedSpec} from '../spec';
 import {keys} from '../util';
-import {VgData, VgLayout} from '../vega.schema';
+import {SubstituteType, VgData, VgLayout} from '../vega.schema';
 import {buildModel} from './buildmodel';
 import {parseData} from './data/parse';
 import {assembleLayoutSignals} from './layoutsize/assemble';
@@ -13,7 +13,12 @@ import {Model} from './model';
 export class ConcatModel extends Model {
   public readonly children: Model[];
 
-  constructor(spec: NormalizedConcatSpec, parent: Model, parentGivenName: string, config: Config<SignalRef>) {
+  constructor(
+    spec: SubstituteType<NormalizedConcatSpec, ExprRef, SignalRef>,
+    parent: Model,
+    parentGivenName: string,
+    config: Config<SignalRef>
+  ) {
     super(spec, 'concat', parent, parentGivenName, config, spec.resolve);
 
     if (spec.resolve?.axis?.x === 'shared' || spec.resolve?.axis?.y === 'shared') {
@@ -59,7 +64,9 @@ export class ConcatModel extends Model {
     // TODO(#2415): support shared axes
   }
 
-  private getChildren(spec: NormalizedConcatSpec): NormalizedSpec[] {
+  private getChildren(
+    spec: SubstituteType<NormalizedConcatSpec, ExprRef, SignalRef>
+  ): SubstituteType<NormalizedSpec, ExprRef, SignalRef>[] {
     if (isVConcatSpec(spec)) {
       return spec.vconcat;
     } else if (isHConcatSpec(spec)) {

src/compile/facet.ts

@@ -4,14 +4,14 @@ import {isBinning} from '../bin';
 import {COLUMN, ExtendedChannel, FacetChannel, FACET_CHANNELS, POSITION_SCALE_CHANNELS, ROW} from '../channel';
 import {FieldName, FieldRefOption, initFieldDef, TypedFieldDef, vgField} from '../channeldef';
 import {Config} from '../config';
-import {ExprRef, replaceExprRef} from '../expr';
+import {ExprRef} from '../expr';
 import * as log from '../log';
 import {hasDiscreteDomain} from '../scale';
 import {DEFAULT_SORT_OP, EncodingSortField, isSortField, SortOrder} from '../sort';
 import {NormalizedFacetSpec} from '../spec';
 import {EncodingFacetMapping, FacetFieldDef, FacetMapping, isFacetMapping} from '../spec/facet';
 import {keys} from '../util';
-import {isVgRangeStep, VgData, VgLayout, VgMarkGroup} from '../vega.schema';
+import {isVgRangeStep, SubstituteType, VgData, VgLayout, VgMarkGroup} from '../vega.schema';
 import {buildModel} from './buildmodel';
 import {assembleFacetData} from './data/assemble';
 import {sortArrayIndexField} from './data/calculate';
@@ -40,7 +40,12 @@ export class FacetModel extends ModelWithField {
 
   public readonly children: Model[];
 
-  constructor(spec: NormalizedFacetSpec, parent: Model, parentGivenName: string, config: Config<SignalRef>) {
+  constructor(
+    spec: SubstituteType<NormalizedFacetSpec, ExprRef, SignalRef>,
+    parent: Model,
+    parentGivenName: string,
+    config: Config<SignalRef>
+  ) {
     super(spec, 'facet', parent, parentGivenName, config, spec.resolve);
 
     this.child = buildModel(spec.spec, this, this.getName('child'), undefined, config);
@@ -82,9 +87,7 @@ export class FacetModel extends ModelWithField {
     // Cast because we call initFieldDef, which assumes general FieldDef.
     // However, FacetFieldDef is a bit more constrained than the general FieldDef
     const facetFieldDef = initFieldDef(fieldDef, channel) as FacetFieldDef<FieldName, SignalRef>;
-    if (facetFieldDef.header) {
-      facetFieldDef.header = replaceExprRef(facetFieldDef.header);
-    } else if (facetFieldDef.header === null) {
+    if (facetFieldDef.header === null) {
       facetFieldDef.header = null;
     }
     return facetFieldDef;

src/compile/layer.ts

@@ -1,10 +1,10 @@
-import {Legend as VgLegend, NewSignal, SignalRef, Title as VgTitle} from 'vega';
+import {Legend as VgLegend, NewSignal, SignalRef, Title as VgTitle, ExprRef} from 'vega';
 import {array} from 'vega-util';
 import {Config} from '../config';
 import * as log from '../log';
 import {isLayerSpec, isUnitSpec, LayoutSizeMixins, NormalizedLayerSpec} from '../spec';
 import {keys} from '../util';
-import {VgData, VgLayout} from '../vega.schema';
+import {SubstituteType, VgData, VgLayout} from '../vega.schema';
 import {assembleAxisSignals} from './axis/assemble';
 import {parseLayerAxes} from './axis/parse';
 import {parseData} from './data/parse';
@@ -21,7 +21,7 @@
   public readonly children: Model[];
 
   constructor(
-    spec: NormalizedLayerSpec,
+    spec: SubstituteType<NormalizedLayerSpec, ExprRef, SignalRef>,
     parent: Model,
     parentGivenName: string,
     parentGivenSize: LayoutSizeMixins,
@@ -39,7 +39,7 @@
       if (isLayerSpec(layer)) {
         return new LayerModel(layer, this, this.getName(`layer_${i}`), layoutSize, config);
       } else if (isUnitSpec(layer)) {
-        return new UnitModel(layer, this, this.getName(`layer_${i}`), layoutSize, config);
+        return new UnitModel(layer, this, this.getName(`layer_${i}`), layoutSize, config) as UnitModel;
       }
 
       throw new Error(log.message.invalidSpec(layer));

src/compile/mark/init.ts

@@ -3,7 +3,6 @@ import {isBinned, isBinning} from '../../bin';
 import {isFieldDef, isNumericDataDef, isUnbinnedQuantitativeFieldOrDatumDef, isTypedFieldDef} from '../../channeldef';
 import {Config} from '../../config';
 import {Encoding, isAggregate} from '../../encoding';
-import {replaceExprRef} from '../../expr';
 import * as log from '../../log';
 import {
   AREA,
@@ -25,10 +24,7 @@ import {QUANTITATIVE, TEMPORAL} from '../../type';
 import {contains, getFirstDefined} from '../../util';
 import {getMarkConfig, getMarkPropOrConfig} from '../common';
 
-export function initMarkdef(originalMarkDef: MarkDef, encoding: Encoding<string>, config: Config<SignalRef>) {
-  // FIXME: markDef expects that exprRefs are replaced recursively but replaceExprRef only replaces the top level
-  const markDef: MarkDef<Mark, SignalRef> = replaceExprRef(originalMarkDef) as any;
-
+export function initMarkdef(markDef: MarkDef<Mark, SignalRef>, encoding: Encoding<string>, config: Config<SignalRef>) {
   // set orient, which can be overridden by rules as sometimes the specified orient is invalid.
   const specifiedOrient = getMarkPropOrConfig('orient', markDef, config);
   markDef.orient = orient(markDef.type, encoding, specifiedOrient);

src/compile/model.ts

@@ -22,7 +22,7 @@ import {ChannelDef, FieldDef, FieldRefOption, getFieldDef, vgField} from '../cha
 import {Config} from '../config';
 import {Data, DataSourceType} from '../data';
 import {forEach, reduce} from '../encoding';
-import {ExprRef, replaceExprRef} from '../expr';
+import {ExprRef} from '../expr';
 import * as log from '../log';
 import {Resolve} from '../resolve';
 import {hasDiscreteDomain} from '../scale';
@@ -38,7 +38,7 @@ import {NormalizedSpec} from '../spec/index';
 import {extractTitleConfig, isText, TitleParams} from '../title';
 import {normalizeTransform, Transform} from '../transform';
 import {contains, Dict, duplicate, isEmpty, keys, varName} from '../util';
-import {isVgRangeStep, VgData, VgEncodeEntry, VgLayout, VgMarkGroup} from '../vega.schema';
+import {isVgRangeStep, SubstituteType, VgData, VgEncodeEntry, VgLayout, VgMarkGroup} from '../vega.schema';
 import {assembleAxes} from './axis/assemble';
 import {AxisComponentIndex} from './axis/component';
 import {signalOrValueRef} from './common';
@@ -187,21 +187,21 @@ export abstract class Model {
   public abstract readonly children: Model[];
 
   constructor(
-    spec: NormalizedSpec,
+    spec: SubstituteType<NormalizedSpec, ExprRef, SignalRef>,
     public readonly type: SpecType,
     public readonly parent: Model,
     parentGivenName: string,
     public readonly config: Config<SignalRef>,
     resolve: Resolve,
-    view?: ViewBackground<ExprRef | SignalRef>
+    view?: ViewBackground<SignalRef>
   ) {
     this.parent = parent;
     this.config = config;
-    this.view = replaceExprRef(view);
+    this.view = view;
 
     // If name is not provided, always use parent's givenName to avoid name conflicts.
     this.name = spec.name ?? parentGivenName;
-    this.title = isText(spec.title) ? {text: spec.title} : spec.title ? replaceExprRef(spec.title) : undefined;
+    this.title = isText(spec.title) ? {text: spec.title} : spec.title;
 
     // Shared name maps
     this.scaleNameMap = parent ? parent.scaleNameMap : new NameMap();

src/compile/projection/parse.ts

@@ -3,7 +3,6 @@ import {hasOwnProperty} from 'vega-util';
 import {LATITUDE, LATITUDE2, LONGITUDE, LONGITUDE2, SHAPE} from '../../channel';
 import {getFieldOrDatumDef} from '../../channeldef';
 import {DataSourceType} from '../../data';
-import {replaceExprRef} from '../../expr';
 import {PROJECTION_PROPERTIES} from '../../projection';
 import {GEOJSON} from '../../type';
 import {deepEqual, duplicate, every} from '../../util';
@@ -17,15 +16,15 @@ export function parseProjection(model: Model) {
 
 function parseUnitProjection(model: UnitModel): ProjectionComponent {
   if (model.hasProjection) {
-    const proj = replaceExprRef(model.specifiedProjection);
+    const proj = model.specifiedProjection;
     const fit = !(proj && (proj.scale != null || proj.translate != null));
     const size = fit ? [model.getSizeSignalRef('width'), model.getSizeSignalRef('height')] : undefined;
     const data = fit ? gatherFitData(model) : undefined;
 
     const projComp = new ProjectionComponent(
       model.projectionName(true),
       {
-        ...replaceExprRef(model.config.projection),
+        ...(model.config.projection ?? {}),
         ...proj
       },
       size,

src/compile/unit.ts

@@ -1,5 +1,4 @@
 import {NewSignal, SignalRef} from 'vega';
-import {isArray} from 'vega-util';
 import {Axis, AxisInternal, isConditionalAxisValue} from '../axis';
 import {
   Channel,
@@ -27,7 +26,7 @@ import {Config} from '../config';
 import {isGraticuleGenerator} from '../data';
 import * as vlEncoding from '../encoding';
 import {Encoding, initEncoding} from '../encoding';
-import {ExprRef, replaceExprRef} from '../expr';
+import {ExprRef} from '../expr';
 import {LegendInternal} from '../legend';
 import {GEOSHAPE, isMarkDef, Mark, MarkDef} from '../mark';
 import {Projection} from '../projection';
@@ -37,7 +36,7 @@ import {LayoutSizeMixins, NormalizedUnitSpec} from '../spec';
 import {isFrameMixins} from '../spec/base';
 import {stack, StackProperties} from '../stack';
 import {keys} from '../util';
-import {VgData, VgLayout} from '../vega.schema';
+import {SubstituteType, VgData, VgLayout} from '../vega.schema';
 import {assembleAxisSignals} from './axis/assemble';
 import {AxisInternalIndex} from './axis/component';
 import {parseUnitAxes} from './axis/parse';
@@ -74,13 +73,13 @@ export class UnitModel extends ModelWithField {
 
   protected specifiedLegends: LegendInternalIndex = {};
 
-  public specifiedProjection: Projection<ExprRef | SignalRef> = {};
+  public specifiedProjection: Projection<SignalRef> = {};
 
   public readonly selection: SelectionParameter[] = [];
   public children: Model[] = [];
 
   constructor(
-    spec: NormalizedUnitSpec,
+    spec: SubstituteType<NormalizedUnitSpec, ExprRef, SignalRef>,
     parent: Model,
     parentGivenName: string,
     parentGivenSize: LayoutSizeMixins = {},
@@ -154,25 +153,13 @@ export class UnitModel extends ModelWithField {
         | PositionFieldDef<string>
         | MarkPropFieldOrDatumDef<string>;
       if (fieldOrDatumDef) {
-        scales[channel] = this.initScale(fieldOrDatumDef.scale ?? {});
+        // TODO: remove as Scale<SignalRef> when we have better types for scale
+        scales[channel] = fieldOrDatumDef.scale as Scale<SignalRef>;
       }
       return scales;
     }, {} as ScaleIndex);
   }
 
-  private initScale(scale: Scale<ExprRef | SignalRef>): Scale<SignalRef> {
-    const {domain, range} = scale;
-    // TODO: we could simplify this function if we had a recursive replace function
-    const scaleInternal = replaceExprRef(scale);
-    if (isArray(domain)) {
-      scaleInternal.domain = domain.map(signalRefOrValue);
-    }
-    if (isArray(range)) {
-      scaleInternal.range = range.map(signalRefOrValue);
-    }
-    return scaleInternal as Scale<SignalRef>;
-  }
-
   private initAxes(encoding: Encoding<string>): AxisInternalIndex {
     return POSITION_SCALE_CHANNELS.reduce((_axis, channel) => {
       // Position Axis
@@ -212,9 +199,7 @@ export class UnitModel extends ModelWithField {
 
       if (fieldOrDatumDef && supportLegend(channel)) {
         const legend = fieldOrDatumDef.legend;
-        _legend[channel] = legend
-          ? replaceExprRef(legend) // convert truthy value to object
-          : legend;
+        _legend[channel] = legend;
       }
 
       return _legend;